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398 - Optical communications

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Class / Patent application numberDescriptionNumber of patent applications / Date published
398208000 Including postcompensation 130
398212000 Including optical element (e.g., lens, mirror, etc.) 22
398214000 Including optical waveguide 18
398204000 Heterodyne 17
398203000 Homodyne 8
20130209111DEMODULATING DELAY CIRCUIT AND OPTICAL RECEIVER - A demodulating delay circuit with a planar lightwave circuit includes: an optical interferometer including input and output couplers, and a first arm waveguide connecting the couplers, and a shorter second arm waveguide. The interferometer delays each bit of a signal by one bit such that the delayed bit interferes with its adjacent bit, and has a bent form such that propagation directions of light in the couplers are different by 180 degrees. The couplers each include first and second waveguides. The first waveguide is longer and the waveguides are closely arranged in parallel at two positions thereby forming directional couplers. The input and output couplers are each configured as a wavelength insensitive coupler having a coupling ratio of 50 percent in a bandwidth used. The first waveguide of the input coupler is arranged on the same side as that on which the first waveguide of the output coupler is arranged.08-15-2013
20100074631FREQUENCY-AGILE INFRARED RECEIVER - An infrared receiver is provided that may include an infrared sensor, a band-pass filter, and a processor. The processor may be configured to transmit a confirmation signal to the band-pass filter if the signal is distinguishable from noise.03-25-2010
20130039665CLOCK PHASE RECOVERY APPARATUS - A clock phase recovery apparatus includes a clock estimator for estimating a first clock signal and a second clock signal upon the basis of an input signal, the input signal comprising a first sub-signal according to a first optical polarization and a second sub-signal according to a second optical polarization, the first clock signal comprising a first clock magnitude and a first clock phase, the second clock signal comprising a second clock magnitude and a second clock phase, and a selector for selecting the first clock phase to form the estimated clock phase if the first clock magnitude is greater than the second clock magnitude, or for selecting the second clock phase to form the estimated clock phase if the second clock magnitude is greater than the first clock magnitude.02-14-2013
20090154940BALANCED OPTICAL SIGNAL PROCESSOR - An apparatus and method for reducing electrical signal intermodulation by processing a balanced electrical signal in the optical domain in a manner adapted to reduce noise and second order intermodulation, and converting the processed optical signal back to an electrical domain signal with either a single or balanced (differential) outputs.06-18-2009
20130039666Current-controlled CMOS logic family - Various circuit techniques for implementing ultra high speed circuits use current-controlled CMOS (C02-14-2013
20090304397LIGHT RECEIVING DEVICE AND LIGHT RECEIVING METHOD - The light receiving device includes a pixel array, such as a two-dimensional pixel array, of pixels each having a light-receiving element for receiving input signal light, an output selecting unit for selecting the outputs of pixels within the pixel array, a selected output adding unit for adding and outputting the selected outputs of the pixels, and an amplifying unit for amplifying the output of the selected output adding unit.12-10-2009
20090304396Optical Receiver and Method of Detecting Loss of Optical Signal of the Optical Receiver - The optical receiver includes: a photoelectric conversion circuit for receiving an optical signal and converting the received optical signal into an electrical signal; a comparator for outputting a first determination signal (S12-10-2009
20090041476METHOD AND APPARATUS FOR PROCESSING SIGNALS OF PHOTO-DETECTOR IN VISIBLE LIGHT COMMUNICATION SYSTEM - Disclosed is a method for processing incoming signals of photo-detectors in a visible light communication system. The method includes: dividing symbol duration into divided durations according to an equal time interval to set the divided durations to a plurality of time slots, the symbol duration being a time required to transmit one of a symbol and a bit; receiving visible light signals through a photodiode array in a receiver; determining a gain value of each of the photodiodes during a time slot, in consideration of each photodiode area on the photodiode array during the time slot and the time slot position within the symbol duration; multiplying a gain value of each of the photodiodes by an output value of a corresponding photodiode; and summing up output values of each of the photodiodes by which the gain value has been multiplied and calculating a total of output values of the time slot.02-12-2009
20090269081Soft Decision Threshold Control in a Signal Receiver Using Soft Decision Error Correction - A soft decision threshold control system and method may be used with a forward error correction (FEC) scheme to adjust or tune one or more soft decision thresholds in response to one or more bit value averages for the threshold(s) and in response to a bit error rate (BER). The bit value average for a soft decision threshold generally refers to an average number of binary values (e.g., logic ones and/or zeros) occurring in a bit stream detected using the soft decision threshold. For different BER levels in a particular system, for example, one or more of the soft decision thresholds may have a predetermined bit value average, which has been determined to provide a certain level of performance (e.g., an optimum performance). Thus, one or more of the soft decision thresholds may be adjusted such that the bit value averages for the soft decision thresholds are adjusted as a function of the BER. The settings of the soft decision thresholds may also be adjusted in response to changes in a signal amplitude of the input signal being detected.10-29-2009
20120224867METHOD AND APPARATUS FOR ALL-OPTICAL DISCRETE FOURIER TRANSFORM INCLUDING ALL-OPTICAL OFDM DEMULTIPLEXING - Various exemplary embodiments relate to an optical discrete Fourier transform device including: a 1×N splitter; N optical delay lines each with an optical phase shifter, wherein the N optical delay lines are coupled to the 1×N MMI device; and an N×N MMI device coupled to the N optical delay lines, wherein the N×N MMI device produces N optical outputs.09-06-2012
20080247766PIN/TIA SYSTEM FOR USE IN FTTx APPLICATIONS - A system is disclosed for an improved ROSA that has increased sensitivity for permitting greater numbers of ONTs to be connected to an optical network per defined transmission line distances. ROSA configuration includes a digital optical module with improved performance characteristics. This digital optical module has replaced a conventional photodiode with a PIN detector that is coupled with the TIA. The resulting the digital optical module containing this PIN/TIA configuration when incorporated in a ROSA provides a single ROSA solution that will meet or exceed the ITU/IEEE FTTx standards for short and long distances under substantially all operating conditions.10-09-2008
20090238581OPTICAL SIGNAL RECEIVING CIRCUIT - To solve problematic trade-off between a bandwidth and a in-band deviation in an optical signal receiving circuit of a gigabit order that is required to have a wide dynamic range, the optical signal receiving circuit has a current-voltage conversion circuit that receives as an input a current signal outputted from a photoelectric conversion circuit for receiving and converting an optical signal into a current signal and converts it into a voltage signal, and realizes the wide dynamic range by providing the current-voltage conversion circuit with an AGC function and a phase compensation function by MOS transistors and a capacitance. Further, by providing the current-voltage conversion circuit with a second phase compensation function by a MOS transistor and a capacitance, it is made possible for the optical signal receiving circuit to reduce the in-band deviation at the time of minimum gain while securing the bandwidth at the time of maximum gain.09-24-2009
20120288286OPTICAL RECEIVER FOR AMPLITUDE-MODULATED SIGNALS - An optical receiver that uses a coherent optical quadrature-detection scheme to demodulate an amplitude-modulated optical input signal in a manner that enables the use of a free-running optical local-oscillator source. The optical receiver employs a signal combiner that combines, into an electrical output signal, the in-phase and quadrature-phase electrical signals generated as a result of the quadrature detection of the optical input signal. Depending on the frequency offset between the local-oscillator signal and the input signal, the electrical output signal produced by the signal combiner can be a desired baseband signal or an intermediate-frequency signal. The latter signal can be demodulated to recover the baseband signal in a relatively straightforward manner, e.g., using a conventional intermediate-frequency electrical demodulator coupled to the signal combiner.11-15-2012
20110280588PARTIAL DPSK (PDPSK) TRANSMISSION SYSTEMS - An optical receiver includes a demodulator having a delay interferometer comprising an optical input that receives a phase modulated optical signal from a bandwidth limited transmission system. The delay interferometer has a free spectral range that is larger than a symbol rate of the phase modulated optical signal by an amount that improves receiver performance. The receiver also includes a differential detector having a first and a second photodetector. The first photodetector is optically coupled to the constructive optical output of the delay interferometer. The second photodetector is optically coupled to the destructive optical output of the delay interferometer. The differential detector combines a first electrical detection signal generated by the first photodetector and a second electrical detection signal generated by the second photodetector to generate an electrical reception signal.11-17-2011
20110280587PMD Insensitive Direct-Detection Optical OFDM Systems Using Self-Polarization Diversity - A self-polarization diversity technique to combat PMD in a direct-detection optical OFDM system. This technique does not require any dynamic polarization control, and can simultaneous compensate PMD in a WDM system with one device. Simulation results show that this technique virtually completely eliminates the PMD impairments in direct-detection optical OFDM systems.11-17-2011
20090003844HIGH SPEED OPTOELECTRONIC RECEIVER - A novel 100+ Gbit/s opto-electronic receiver uses hybrid integration of a photodiode and a demultiplexer. The photodiode converts a high speed optical data stream to an electrical data stream that is input to an electronic demultiplexer. The photodiode and the demultiplexer are connected together by a novel planar microwave transmission structure.01-01-2009
20090202259Current mirror circuit and optical receiver circuit using the same - A current mirror circuit and an optical receiver circuit implementing with the current mirror circuit are disclosed. The current mirror circuit provides two MOSFETs and two differential amplifiers. The MOSFETs are operated under the same bias condition even the power supply voltage decreases due to the virtual short-circuit characteristic between two inputs of the differential amplifier. One of the differential amplifiers provides a variable gain and output impedance characteristic to stabilize the feedback loop formed by this differential amplifier and one of the MOSFETs.08-13-2009
20110293292Mitigating Signal Offsets in Optical Receivers - An optical receiver circuit is disclosed in which a number of electrical signals are processed to extract data encoded therein. The electrical signals may be compared during the process to selectively remove one or more waveforms from one or more corresponding electrical signals. Various data signals, each including one or more waveforms, may then be processed to extract the encoded data. The optical receiver circuit reduces, or eliminates, electrical offsets which may be present in one or more of the electrical signals to reduce corresponding errors in the encoded data signals.12-01-2011
20110293293TRANS-IMPEDANCE AMPLIFIER WITH VARIABLE BANDWIDTH AND DIGITAL COHERENT OPTICAL RECEIVER INSTALLING THE SAME - A trans-impedance amplifier (TIA) with an adjustable bandwidth is disclosed. The TIA of the present invention includes the amplifying stage and the emitter follower stage arranged in the downstream of the amplifying stage. The transistor in the amplifying stage includes a diode in the emitter thereof to provide a substantial emitter level to the transistor. This diode is biased by another current source with a variable function. The operating point of the diode, in particular, the differential resistance thereof, is variable by the current source, which adjusts the bandwidth of the TIA without affecting the phase characteristic of the TIA.12-01-2011
20090028581Burst mode optical receiver and system and method therefor - A communications system includes an optical receiver for receiving optical signals and for converting the optical signals into electrical signals, a transimpedance amplifier (“TIA”) for filtering the electrical signals, a limiting amplifier coupled with the TIA, an automatic threshold control (“ATC”) coupled with the TIA for providing a reference voltage for the limiting amplifier. The ATC further includes a common emitter circuit and an emitter follower circuit, wherein logic high signals and logical low signals in the electrical signals are determined based on the reference voltage output from the ATC.01-29-2009
20090103931SYSTEMS AND METHODS FOR THE COHERENT NON-DIFFERENTIAL DETECTION OF OPTICAL COMMUNICATION SIGNALS - In various exemplary embodiments, the present invention provides coherent non-differential detection systems and methods for the detection of optical communication signals by the Brillouin fiber amplification of an optical communication signal carrier, the coherent non-differential detection systems including: a Sagnac loop including a single-mode fiber span; a fiber span with negligible birefringence (i.e. a spun fiber span or the like); or a fiber loop with negligible birefringence (i.e. a spun fiber loop or the like).04-23-2009
20110008059DIGITAL EQUALIZATION APPARATUS AND METHOD FOR COHERENT OPTICAL RECEIVER - Disclosed are a digital equalization apparatus for a coherent optical receiver and a digital equalization method for a coherent optical receiver, capable of compensating for chromatic dispersion and polarization impairment through a digital signal processing, and capable of performing a clock recovery and a data recovery through a digital symbol synchronization. The digital equalization apparatus and the method compensate for various impairments occurring on an optical path in a digital manner and achieve synchronization through a simple structure.01-13-2011
20090208227OPTICAL APPARATUS AND USE METHOD THEREOF FOR PASSIVE OPTICAL NETWORK SYSTEM - An optical apparatus receives an upward signal light from a plurality of subscriber units, where the upward signal light is composed of a plurality of time slots corresponding to the plurality of optical subscriber units. The optical apparatus includes a driving unit configured to determine a respective required gain for light from each of the plurality of optical subscriber units, an amplifying section configured to amplify the upward signal light with the required gain corresponding to the time slots of the upward signal light, and a receiver configured to receive the amplified upward signal light.08-20-2009
20100272448OPTICAL BURST SIGNAL RECEIVING DEVICE - An optical burst signal receiving device includes: a photoelectric conversion unit that photoelectrically converts an input optical burst signal into a current burst signal and outputs the current burst signal; a transimpedance amplifier that converts the current burst signal output from the photoelectric conversion unit into a phase-inverted voltage burst signal; an equalizing amplifier that performs equalizing amplification on the output signal from the transimpedance amplifier and then outputs the resulting signal; a level detection circuit that detects the level of the output signal from the transimpedance amplifier; and an automatic gain control circuit that controls at least one of the transimpedance amplifier and the equalizing amplifier such that the optimum gain is attained for the level of a burst cell detected by the level detection circuit, in which the level detection circuit has: a monitor window generating unit that generates a monitor window signal that regulates a level detection block, which is a predetermined period commencing from the start point of a preamble portion of the burst cell; a reference voltage generating circuit that generates a reference voltage signal; a threshold value comparator that compares the level of the output signal from the transimpedance amplifier with the level of the reference voltage signal; and an AND circuit that performs an AND operation on the monitor window signal output from the monitor window generating unit and the output from the threshold value comparator.10-28-2010
20120189324SOFT-INPUT GENERATION FOR SOFT-DECISION FEC DECODING - A soft-decision forward error correction scheme for received optical signals is described. Differential decoding may be performed, for example, in each polarization after coherent QPSK detection. Hard decisions may be made based on judging the most likely transition between each pair of received input symbols. Soft-input generation is also described, representing the reliability of the hard decisions. The soft-input information may be generated through simplified algorithms that utilize the most likely transitions to determine a reliability assignment.07-26-2012
20100119240RECEIVING APPARATUS AND RECEIVING METHOD - A receiving apparatus is provided, which includes: a photoelectric detector (PD), adapted to generate current signals according to optical signals projected on the PD and digitally modulated at a high or low rate; a first switch, adapted to switch to output the high-rate or low-rate current signals; a first transimpedance amplifier (TIA), adapted to amplify the high-rate current signals into high-rate voltage signals; and a second TIA, adapted to amplify the received low-rate current signals into low-rate voltage signals. Therefore, in the present invention, high-rate and low-rate receiving paths are completely separated. This provides signals with good quality and avoids signal deterioration; and switching between the high-rate and low-rate receiving paths simplifies the structure and lowers costs.05-13-2010
20100067924OPTICAL RECEIVER - An optical receiver of wide-dynamic range characteristic that stably reproduces a burst signal having different light receiving levels. A preamplifier converts an output from a light receiving element into a voltage signal. A level detecting circuit includes: a first level detecting unit having a shorter time constant; and a second level detecting unit having a longer time constant and switching over to any of the level detecting units in response to a time constant switching signal to detect a voltage level of an output voltage signal output from the preamplifier. An amplifier variably controls conversion gain of the preamplifier based on the detecting result. A time constant switching control outputs the time constant switching signal to the level detecting unit based on the output voltage signal from the preamplifier, to select the first level detecting unit or the second detecting unit based on a number of consecutive identical digits being equal to, smaller, or larger than the predetermined number.03-18-2010
20100098437OPTICAL RECEIVER APPLICABLE TO MULTIPLE TRANSMISSION SPEED - The present invention provides an optical receiver that enables to vary the sensitivity depending on the transmission speed. The optical receiver provides a photodiode to generate the photocurrent, the pre-amplifier to convert the photocurrent to the voltage signal, the lead pin to supply the bias voltage to the photodiode, and the control block to generate the switching signal for varying the current-to-voltage conversion efficiency and the frequency bandwidth of the pre-amplifier based on the control signal. The control signal is commonly provided from the lead pin through which the bias voltage is applied. The control block interprets the signal applied to the lead pin and generates the switching signal.04-22-2010
20080212981OPTICAL RECEIVER AND VISIBLE LIGHT COMMUNICATION SYSTEM - A data signal to be transmitted is supplied to a modulator of a transmitter, and the modulator modulates the output of a blue light-excited white LED and outputs blue LED light and phosphor light. The modulated blue light enters to a photo-electric converter through an LED light transmission color filter. The modulated phosphor light on the other hand enters to another photo-electric converter through a phosphor light transmission color filter. The photo-electric converters convert incident light to electric signals. The converted signals are amplified by amplifiers. Then, equalizers emphasize the harmonic component therein according to the response characteristic of the blue light and the response characteristic of the phosphor light for reduction of the dullness of waveforms.09-04-2008
20080240736Inter-Symbol Interference-Suppressed Colorless DPSK Demodulation - An optical device includes an interferometer for a received optical differential phase shift keying DPSK signal, and an equalizer integrated with the interferometer in a manner for reducing from optical filtering effects an interference by signal bits of the DPSK signal with signal bits of a contiguous DPSK signal. The interferometer is a Michelson delay interferometer type, but can also be a Mach-Zehnder delay interferometer type on fiber, waveguide or other optical structure. The equalizer is a Fabry-Perot type equalizer, but can be a ring resonator type or a fiber based equalizer.10-02-2008
20080240738OPTICAL RECEIVER, OPTICAL COMMUNICATION DEVICE, AND OPTICAL SIGNAL RECEIVING METHOD - An optical receiver including a demodulator to convert an in-phase signal of a received differential phase modulated optical signal into a first electrical signal, and to convert a quadrature signal of the received differential phase modulated optical signal into a second electrical signal; a decision member deciding logic states of the first and second electrical signals; a logic controller using the decision result of the decision member to control logic states of the first and second electrical signals; and a memory storing information relating to the decision result. The logic controller controls the logic state using the information relating to the decision result stored in the memory.10-02-2008
20080273881BURST LIGHT RECEIVER, OPTICAL COMMUNICATION SYSTEM, BURST LIGHT RECEPTION CONTROL METHOD AND RECORDING MEDIUM WITH PROGRAM RECORDED THEREIN - To enhance resistance against external factors such as junk data and noise in the burst signal by use of a simple configuration without separately requiring other dedicated circuits such as a mask signal generator, a burst light receiver includes an information restoring unit for receiving a signal from an optical signal receiving unit and extracting therefrom information of a clock signal and data to restore the information and a timing control unit for making the information restoring unit execute burst reset processing at timing of release of a reception interruption signal indicating absence of an optical signal to the optical signal receiving unit.11-06-2008
20100054759Method for Electric Power Supply of Optical Receiver, Digital Signal Processing Circuit, and Optical Receiver - In a digital signal processing circuit of an optical receiver applicable to this method for electric power supply control, tap coefficients of a filter used in a waveform equalization section are calculated in a tap coefficient calculating section, based on a state of an optical fiber transmission line. Then, among the calculated tap coefficients, a tap coefficient for which an absolute value is less than a previously determined threshold is determined, and electric power supply to a circuit part of a filter corresponding to the tap coefficient is stopped. As a result, for an optical receiver that performs digital signal processing, it is possible to reduce the power consumption, while realizing waveform equalization at a high accuracy.03-04-2010
20080199190OPTICAL RECEIVER - An optical receiver comprising: a photoelectric converting unit converting an input optical signal into an converted electrical signal; a splitting unit splitting the converted electrical signal into a plurality of split electrical signals; an amplifier amplifying one of the plurality of the split electrical signals with a first input time constant and thereby outputting an output signal; a detection circuit detecting an interruption of the input optical signal with a second input time constant on the basis of one of the plurality of the split electrical signals other than the one of the plurality of the split electrical signals input to the amplifier and thereby outputting a detection signal; and a delay circuit configured to delay the detection signal; wherein, the second input time constant of the detection circuit is smaller than the first input time constant of the amplifier.08-21-2008
20110008060METHOD AND SYSTEM FOR OPTOELECTRONIC RECEIVERS FOR UNCODED DATA - A method and system for optoelectronic receivers for uncoded data are disclosed and may include amplifying received electrical signals in a signal amplifier comprising differential gain stages with signal detectors coupled to the outputs. First and second output voltages may be tracked and held utilizing the signal detectors. A difference between the tracked and held value may be amplified in a feedback path of the gain stage, which enables the dynamic configuration of a decision level. The received electrical signals may be generated from an optical signal by a PIN detector, an avalanche photodiode, or a phototransistor. The electrical signal may be received from a read channel. The feedback path may comprise digital circuitry, including an A/D converter, a state machine, and a D/A converter. The detectors may comprise envelope detectors utilized to detect maximum or minimum voltages. The signal amplifier may be integrated in a photonically-enabled CMOS chip.01-13-2011
20120070159SIGNAL GENERATING CIRCUIT, OPTICAL SIGNAL TRANSMITTING APPARATUS, SIGNAL RECEIVING CIRCUIT, METHOD FOR ESTABLISHING OPTICAL SIGNAL SYNCHRONIZATION, AND OPTICAL SIGNAL SYNCHRONIZATION SYSTEM - To enable signal position detection, frequency offset compensation, clock offset compensation, and chromatic dispersion amount estimation in a communication system based on coherent detection using an optical signal, even on a signal having a great offset in an arrival time depending on a frequency due to chromatic dispersion. An optical signal transmitting apparatus generates specific frequency band signals having power concentrated on two or more specific frequencies and transmits a signal including the specific frequency band signals. An optical signal receiving apparatus converts a received signal into a digital signal, detects positions of the specific frequency band signals from the converted digital signal, estimates frequency positions of the detected specific frequency band signals, and detects a frequency offset between an optical signal receiving apparatus and an optical signal transmitting apparatus. Moreover, the optical signal receiving apparatus detects a clock offset between the optical signal receiving apparatus and the optical signal transmitting apparatus from an interval between the estimated frequency positions of the specific frequency band signals. Furthermore, the optical signal receiving apparatus estimates temporal positions of the detected specific frequency band signals and detects a chromatic dispersion amount from a difference between the temporal positions of the specific frequency band signals corresponding to different frequencies.03-22-2012
20110222866Multirate Burst Mode Receiver - There is a need to provide a multirate burst mode receiver for an OLT to be capable of receiving a high-speed burst signal without the need for a special capability of an ONU in a PON system including a mix of ONUs at different transmission bit rates. A multirate burst mode receiver according to the invention includes a signal input discrimination section and a bit rate discrimination section. The signal input discrimination section detects an average amplitude to discriminate signal input. The bit rate discrimination section detects an envelope curve for a high-frequency component to discriminate a signal bit rate. Based on a discrimination result from the signal input discrimination section and the bit rate discrimination section, the multirate burst mode receiver switches a setting for an optical signal reception section and a serial-parallel converter corresponding to the reception bit rate.09-15-2011
20090257756Optical receiver and optical phase control method thereof - An optical receiver includes: delay interferometers respectively provided in at least two branches that branch a reception signal; a phase shift amount control device that controls a phase shift amount of the delay interferometer in accordance with an optical phase control value; a balanced optical detecting section that respectively photoelectrically converts respective branch signals output from the delay interferometers; a data regenerating section that regenerates transmission data from the photoelectrically converted branch signals output from the balanced optical detecting section; a control section that outputs the optical phase control value based on a signal of the data regenerating section; and a memory that stores therein the optical phase control value output from the control section at the time of signal communication, as a history of control values, wherein the control section refers to the history of control values during a signal communication operation to determine the optical phase control value.10-15-2009
20090202258Method for improving the performance of phase-modulated communication systems in an optical network - A method and system for improving the performance of a differential-phase modulated optical communication system is disclosed. The system comprises a demodulator having a tunable element to adjust the free-spectral range (FSR) thereof, and a tunable phase shifter to adjust a frequency of a signal passing therethrough.08-13-2009
20110229152Bit-Rate Discrimination Method and Its Apparatus - In the present invention, unlike a conventional circuit, discrimination is not made by integrating a logical code that includes “0” and “1” to some extent and produced from a random code, but repetition of an identical pattern of a well-known preamble signal added to a head portion of a signal is discriminated when a bit-rate of the signal is changed. More specifically, the repetition of the identical pattern is converted into a consecutive identical signal to generate the consecutive identical signal (having a length of tens bits to thousands bits). Although the consecutive identical signal is longer than a same-code continuation length included in the signal, and is shorter than a time constant necessary to the conventional circuit by about one to three digits. Therefore, an integration time can be shortened to the same degree as the generated consecutive identical signal length, and the bit-rate can be discriminated at high speed within a preamble signal receiving time.09-22-2011
20090097865METHOD AND SYSTEM FOR A NARROWBAND, NON-LINEAR OPTOELECTRONIC RECEIVER - Methods and systems for a narrowband, non-linear optoelectronic receiver are disclosed and may include amplifying a received signal, limiting a bandwidth of the received signal, and restoring the signal utilizing a level restorer, which may include a non-return to zero (NRZ) level restorer. The NRZ level restorer may include a pulse-triggered bistable circuit, which may include two parallel inverters, with one being a feedback path for the other. The inverters may be single-ended or differential. A photogenerated signal may be amplified in the receiver utilizing a transimpedance amplifier and programmable gain amplifiers (PGAs). A received electrical signal may be amplified via PGAs. The bandwidth of the received signal may be limited utilizing one or more of: a low pass filter, a bandpass filter, a high pass filter, a differentiator, or a series capacitance on the chip. The signal may be received from a photodiode integrated on the chip.04-16-2009
20080317477LASER RANGEFINDER AND METHOD FOR DIGITAL SIGNAL PROCESSING THEREOF - A method for digital signal processing is disclosed. Reflected laser signals are received and digitized to generate corresponding digital signals. The digital signals are accumulated to generate an accumulated signal. A digital filtering operation is applied to the accumulated signal to generate a filtered signal. A maximum signal value for the filtered signal is found and a threshold value is set accordingly. It is determined whether the maximum signal value is less than the threshold value, and, if not, a distance value is calculated.12-25-2008
20080232821Optical receiver having transfer function bandwidth selection - An optical receiver apparatus and methods for mitigating intersymbol interference (ISI) in a differentially-encoded modulation transmission system by controlling constructive and destructive transfer functions. The receiver includes a bandwidth control element for controlling transfer function bandwidth, a transfer phase controller for controlling transfer function phase and/or an imbalancer for imbalancing the transfer functions for compensating for intersymbol interference and optimizing the quality of the received optical signal.09-25-2008
20080310860Method and Apparatus for Decision Threshold Control In An Optical Signal Receiver - A method of adjusting a decision threshold in an optical signal receiver. A forward error correction (FEC) decoder provides a feedback signal representative of corrected errors. The decision threshold is adjusted in response to a polarity of the received signal and to balance a number of corrected ones and zeros.12-18-2008
20120141144SYSTEM AND METHOD FOR GENERATING SOFT DECISION RELIABILITY INFORMATION FROM HARD DECISIONS IN AN OPTICAL SIGNAL RECEIVER - A system and method for generating soft decision reliability information from hard decisions in an optical signal receiver. The receiver may include a digital signal processor including a symbol reliability function for generating symbol reliability information associated with symbols encoded on optical signal. The symbol reliability information may be generated as a function of the symbols and hard decision outputs associated with the symbols.06-07-2012
20090116850RESONANT QUANTUM WELL MODULATOR DRIVER - A drive circuit and method of controlling a quantum well modulator are disclosed. The drive circuit can be disposed in an optical transceiver having a quantum well modulator configured to retro-modulate an incoming optical signal. The drive circuit can include separate modulating and bias voltage sources. A level of the modulating voltage and the bias voltage can be determined based on an ambient temperature of the optical transceiver and can be adjusted to compensate for variations in the optical performance of the quantum well modulator. The quantum well modulator can be controlled in intervals. The modulating voltage can be applied to the quantum well modulator during a first interval. A current associated with the modulating voltage can be returned to the modulation voltage source during a second interval. A timing of the first and second intervals can be based on electrical properties of the quantum well modulator.05-07-2009
20100254718OPTICAL RECEIVER AND METHOD FOR OPTICAL RECEPTION - In-phase signal light and quadrature-phase signal light obtained by mixing input light and local light with each other are converted into digital signals. The quality of a signal to be received is monitored with reference to information obtained through digital signal processing, and the power ratio between the input signal light and the local light that are to be mixed with each other are controlled on the basis of the result of the monitoring.10-07-2010
20120170946TRANSLATION OF RAW FORMATTED INFRARED CODES - A method of translating raw formatted IR codes to discrete formatted IR codes. A raw formatted IR message representing an IR code can be detected. The IR message can include a raw formatted device ID including a first series of IR pulses and a raw formatted command ID including a second series of IR pulses. The IR message can be encoded into a definition that defines the first and second series of pulses contained in the IR message. Encoded data corresponding to the device ID and the command ID can be identified. The encoded data corresponding to the device ID can be matched to a particular device to identify a discrete formatted device ID. The encoded data corresponding to the command ID can be matched to a particular command to identify a discrete formatted command ID. The discrete formatted device ID and the discrete formatted command ID can be stored.07-05-2012
20100189446OPTICAL SIGNAL PROCESSING - Optical signal processing apparatus for processing packetised optical signals comprising a probe signal generator which is arranged to issue a plurality probe pulses, and an optical AND logic gate assembly, the arrangement of the apparatus being such that, in use, the probe signals have an interval between pulses substantially equal to the interval between data elements of the packetised data to be extracted, and the packetised data and the probe pulses are then combined by the AND logic gate assembly.07-29-2010
20130216239System and Method for Blind Equalization and Carrier Phase Recovery in a Quadrature Amplitude Modulated System - A system and method for blind equalization of a QAM signal. Equalization is achieved using an algorithm characterized by cost function that is a function the Euclidian distance, e.g. the minimum Euclidian distance, between points of the constellation associated with the QAM signal, i.e. the distance between symbols.08-22-2013
20100221019Low-noise parallel cascade of optical receivers - A method includes cascading outputs from a plurality of photodiodes connected in parallel; and amplifying the cascaded outputs. An apparatus, includes a plurality of photodiodes cascaded in parallel; and an amplifier coupled to the plurality of photodiodes.09-02-2010
20100254719DEVICE AND METHOD FOR RECEIVING DQPSK SIGNAL AND METHOD FOR OBTAINING DQPSK SIGNAL - A device and a method for receiving a differential quadrature phase shift keying (DQPSK) signal and a method for obtaining a DQPSK signal are provided. The device includes: a splitter, configured to split the DQPSK signal to obtain two optical signals; two optical bandpass filters, connected to the splitter and configured to optically bandpass filter the two optical signals respectively, in which the two optical bandpass filters respectively have a positive frequency offset and a negative frequency offset from a central frequency of the DQPSK signal received by the splitter; and two photoelectric detectors, correspondingly connected to the two optical bandpass filters and configured to photoelectrically convert the filtered optical signals to obtain data signals. In the method, the DQPSK signal is filtered and demodulated by the optical bandpass filters, and then photoelectrically converted by the photoelectric detectors to recover the data signals, such that the problems of poor stability and polarization dependence caused by the Mach-Zehnder interferometer (MZI) are avoided, thereby greatly improving the performance of an optical transmission system.10-07-2010
20110026939INFRARED-RECEIVING DEVICE WITH EXPANDED MODULE AND RECEIVING METHOD FOR THE SAME - An infrared-receiving device includes an infrared-receiving module, an expanded module, and a microprocessor control unit (MCU). The MCU receives a data pulse signal transmitted from the infrared-receiving module. The expanded module is electrically connected to the infrared-receiving module and the MCU to receive a substitution data pulse signal outputted from an external expanded device. The expanded module sends the substitution data pulse signal to the MCU to send a control command to an electronic appliance electrically connected to the MCU.02-03-2011
20090220249DEMODULATION CIRCUIT - A demodulation circuit for reproducing transmitted data from a signal received by a receiver, the demodulation circuit includes a selector, converters and data recovery circuits. The selector demultiplexes the transmitted data into a plurality of divided signals. The converters receives the divided signal from the selector, respectively, the plurality of converters including a delay device and an adding circuit, the delay device for delaying the divided signal from the selector and for outputting a delayed signal, the adding circuit for adding the divided signal from the selector to the delayed signal from the delay device. The plurality of data recovery circuits receives an output signal from the adding circuits, respectively, each of the data recovery circuits discriminating the output signal from the adding circuit.09-03-2009
20090142074OPTICAL RECEIVING APPARATUS, OPTICAL LINE TERMINAL APPARATUS, AND OPTICAL NETWORK SYSTEM - The optical receiving apparatus of the present invention is provided with an optical receiving unit which receives a burst optical signal and outputs a signal in accordance with an optical reception level, a preamplification unit which amplifies the signal from the optical receiving unit, a direct-current component removing unit which removes a direct-current component of a signal output from the preamplification unit and has a variable response time constant, and a time-constant control unit which controls the response time constant of the direct-current component removing unit based on a signal indicating the rising edge of the burst optical signal and a signal indicating the falling edge of the burst optical signal. According to this constitution, the shortening of the rise time and the securing of the tolerance against the same code succession can be simultaneously realized.06-04-2009
20080292325HIGH IMMUNITY CLOCK REGENERATION OVER OPTICALLY ISOLATED CHANNEL - An optically isolated circuit device includes a first opto-isolator circuit that is driven by a first clock signal, and the output of the first opto-isolator circuit is used to drive a phase-locked loop (PLL) that is configured to synthesize a second clock signal having a frequency that is a multiple of the first clock signal frequency. The second clock signal is used as an input to a suitable clocked circuit of a type that benefits from optical isolation, such as an analog-to-digital converter (ADC).11-27-2008
20110129233BURST-MODE OPTICAL RECEIVER AND TIMING CONTROL METHOD - A burst-mode optical receiver and a timing control method are provided. The receiver receiving the burst-mode optical signal includes a transimpedance amplifier (TIA) for receiving a single current information signal and converting the single current information signal into a single voltage signal, a differential signal converter for converting the single voltage signal, received from the TIA, into differential signals, and an automatic offset control limiting amplifier (AOC-LA) for automatically controlling and amplifying an offset of the differential signals. The receiver further includes a gain controller for generating a gain value control signal based on an intensity of a burst packet of the single voltage signal to control a gain value of the TIA, and a burst detector for receiving the differential signals, detecting burst packets, and generating a burst detection signal for the start timing of each of the burst packets.06-02-2011
20110026940OPTICAL COMMUNICATION DEVICE - An optical communication device using a digital coherent reception system includes a phase detector configured to generate, based on a signal obtained in a course of digital signal processing, a phase signal indicating a displacement of a sampling of a reception signal, a clock switch-determiner configured to switch from an reference clock to a clock of transferred data when a value of an amplitude of the phase signal exceeds a given threshold value, and a selector configured to synchronize the sampling of the reception signal and an internal clock of the digital signal processing with the reference clock at start time or signal loss time, and synchronize the sampling of the reception signal and the internal clock with the line clock of the reception signal except for the start time and the signal loss time.02-03-2011
20110110674METHOD AND DEVICE FOR PROCESSING TERAHERTZ WAVES - A method for processing received electromagnetic radiation includes receiving electromagnetic radiation having a plurality of carrier waves in the frequency range between 0.1 and 10 terahertz and having modulated onto the carrier waves information with a signal frequency of less than 50 GHz. The received radiation is filtered with a filter that is tunable in the frequency range from 0.1 to 10 terahertz so as to obtain at least one carrier wave as a terahertz signal. The terahertz signal is provided to a detection circuit that is sensitive to the terahertz signal frequency.05-12-2011
20100322639DEMODULATION OF AN OPTICAL SIGNAL UNDER CONTROL OF A KALMAN FILTER - An optical receiver and a method of demodulating an optical signal. The method includes combining a received optical signal with a local oscillator signal to construct a complex signal indicative of an optical field of the modulated optical signal and processing the complex signal recursively under control of a Kalman filter that enforces a constraint. The receiver includes an optical hybrid that combines a received optical signal with a local oscillator signal, a detector that recovers components of a complex signal, a processor that receives these components, and instructions that cause the processor to process the components of the complex signal recursively under control of a Kalman filter that enforces a constraint to recover data.12-23-2010
20110033194REMOTE CONTROL SIGNAL RECEIVING CIRCUIT - The invention is directed to decreasing the power consumption of a remote control signal receiving circuit. A receiving circuit includes a timing signal generation circuit generating a timing signal, a power supply circuit intermittently operating a light receiving element receiving a remote control signal by supplying power to the light receiving element when the timing signal is at a first level and by halting supplying power to the light receiving element when the timing signal is at a second level, a sampling signal generation circuit generating a sampling signal during the operation of the light receiving element corresponding to the timing signal, a sampling circuit sampling an output signal from the light receiving element corresponding to the sampling signal, and a detection circuit detecting the output signal sent from the light receiving element and sampled by the sampling circuit.02-10-2011
20110116810Optical Burst Mode Clock and Data Recovery - An optical receiver, transmitter, transceiver or transponder for bursty, framed or continuous data. The optical receiver includes a burst mode clock recovery module that recovers the clock rapidly and with a small number of preamble or overhead bits at the front end of the data. A local clock is used for timing when the recovered clock is not available. Transitions between the recovered clock and local clock are smoothed out to avoid undesirable artifacts.05-19-2011
20110116809PHASE RECOVERY DEVICE, PHASE COVERY METHOD AND RECEIVER FOR 16 QAM DATA MODULATION - The present invention relates to a phase recovery device, phase recovery method and receiver for 16 QAM data modulation. The phase recovery device comprises: a fourth power calculator for calculating fourth power values of respective symbols in a symbol block; a classification unit for classifying respective symbols in the symbol block based on amplitudes, so as to classify respective symbols in the symbol block into a first category having a large or small amplitude, and a second category having an intermediate amplitude; a reference point determination unit for determining a reference point based on categories of respective symbols in the symbol block and their fourth power values; a rotation unit for rotating respective symbols in the symbol block undergone the fourth power operations and being classified into the second category, based on the reference point; and a phase estimation unit for performing phase estimations based on respective symbols in the symbol block undergone the fourth power operations and being classified into the first category, and respective rotated symbols in the symbol block undergone the fourth power operations and being classified into the second category.05-19-2011
20100014875OPTICAL RECEIVER - An optical detector includes a photoelectric conversion circuit converting an optical input signal into an electrical signal, an AC-to-DC signal conversion circuit converting the electrical signal to a DC signal, a high voltage generating circuit supplying a voltage to the photoelectric conversion circuit, and a current sink circuit drawing a current from the high voltage generating circuit. The current drawn into the current sink circuit from the high voltage generating circuit increases as an output signal of the AC-to-DC signal conversion circuit decreases.01-21-2010
20100054758Optical Receiver With Threshold Voltage Compensation - An optical receiver includes an optical detector having an input that is positioned to detect an optical data signal. The optical detector generates a voltage at an output that is proportional to an optical intensity of the optical data signal. A differential amplifier includes a data input that is electrically connected to the output of the optical detector and a decision threshold voltage signal input. The differential amplifier generates a data signal at a data output and an inverse data signal at a data_bar output. A decision threshold voltage signal generator includes an output that is coupled to the decision threshold voltage signal input of the differential amplifier. The decision threshold voltage signal generator generates a decision threshold voltage signal having an amplitude that causes the differential amplifier to maintain a substantially constant differential voltage between the data signal and the inverse data signal generated.03-04-2010
20090028580Optical reception apparatus and controlling method thereof - The optical reception apparatus of the invention branches into two an RZ-DQPSK optical signal input from an optical transmission path via an optical amplifier, respectively sends this to delay interferometers and photoelectric converters on a pair of arms, separately detects a number of generated errors for the signals propagating through the arms in an error-number detection circuit, obtains a difference in the respective number of generated errors in an error-number detector, and controls phase shift in the delay interferometers so that the difference is within a preset tolerance. By so doing, it is possible to realize excellent reception performance by suppressing the occurrence of the burst error.01-29-2009
20110069975Digital Coherent Detection of Multi-Carrier Optical Signal - Embodiments for optical communication are provided in which subbands of a multi-carrier optical signal are digital coherent detected and then processed to recover data carried by the modulated carriers corresponding to at least one of the subbands. An exemplary optical communication system includes a multi-carrier coherent optical receiver for receiving a multi-carrier optical signal having M modulated carriers that are frequency locked, wherein M is greater than 2. The multi-carrier coherent optical receiver includes a subband digital coherent detector configured to provide output signals in a digital form for N different subbands of the multi-carrier optical signal, where N is an integer greater than 1 and less than M; and a digital signal processor configured to process the digital form of the detected output signals in order to recover the data carried by the modulated carriers corresponding to at least one of the subbands of the multicarrier optical signal.03-24-2011
20100310260Optical Receiver - The interference phases of two optical delay line interferometers of an optical receiver adopting the DQPSK or the like are stabilized at points, which have a difference of 90°, without bifurcation of a receiving signal or receiving data. A low-speed photocurrent flowing through the current source terminal of a photodetector that receives interfering light outputted from an optical delay line interferometer is detected. The interference phase is identified by utilizing a variation in the AC or DC component of the photocurrent dependent on the interference phase of the optical delay line interferometer. The difference between the interference phases of two optical delay line interferometers is controlled to be 90°.12-09-2010
20100303473Receiver and Method for Operating Said Receiver - A receiver contains a phase demodulator and an electronic dispersion compensator that is electrically connected to the phase demodulator. The phase demodulator contains a delay that is equal to or less than 1 bit. Ideally the delay is an adjustable delay. Further, a method for operating the receiver described above is discussed.12-02-2010
20090022502Receiving apparatus - A receiving apparatus which suppresses threshold-voltage changes. A peak voltage detection block detects the peak voltage of a signal. A bottom voltage detection block detects the bottom voltage of the signal. A stop control block generates a stop signal for stopping the operations to detect the peak voltage and the bottom voltage. A threshold value specification block specifies a threshold voltage derived from the peak voltage and the bottom voltage. When receiving the stop signal, the peak voltage detection block stops the operation to detect the peak voltage and retains the peak voltage detected before the reception of the stop signal while the same signal is being received. When receiving the stop signal, the bottom voltage detection block stops the operation to detect the bottom voltage and retains the bottom voltage detected before the reception of the stop signal while the same signal is being received.01-22-2009
20090252504Optical Receiver - Provided is an optical receiver which has a wide dynamic range characteristic for stably reproducing packets having different light receiving levels, and which is superior in high-speed responsiveness and consecutive same binary symbols tolerance.10-08-2009
20110150503Receiver Algorithms for Coherent Detection of Polarization-Multiplexed Optical Signals - A digital signal processor (DSP) operating within, for example, an optical receiver wherein the DSP processes complex sample streams derived from a modulated optical signal, the DSP configured to perform a method of acquiring an intermediate frequency (IF) signal from within the received optical signal, the method comprising: processing at least one block of complex sample stream symbols using a frequency locked loop (FLL) to achieve an initial constellation lock condition, the FLL having a nominal lock-in spectral region; if an initial constellation lock condition is not achieved within a predetermined amount of time, shifting the spectral region processed by the FLL to a spectral region proximate a current operating spectral region.06-23-2011
20100178065DELAY PROCESSING APPARATUS, SIGNAL AMPLIFICATION APPARATUS, OPTO-ELECTRIC CONVERSION APPARATUS, ANALOG-DIGITAL CONVERSION APPARATUS, RECEIVING APPARATUS, AND RECEIVING METHOD - A delay device that provides a delay amount to at least one of the in-phase signal and the quadrature signal, and a delay control section that controls the delay amount provided by the delay device based on a quality of the signals when the in-phase signal and the quadrature signal, to the at least one of which the delay amount is provided, at the delay device are converted into digital signals by the analog-digital converter, and the digital signal processing is carried out at the processor are provided. Thereby, the signal quality of recovered data at a receiving end of a multi-level phase modulation communication system is improved.07-15-2010
20120177385HOLEVO CAPACITY ACHIEVING JOINT DETECTION RECEIVER - An optical receiver may include a unitary transformation operator to receive an n-symbol optical codeword associated with a codebook, and to perform a unitary transformation on the received optical codeword to generate a transformed optical codeword, where the unitary transformation is based on the codebook. The optical receiver may further include n optical detectors, where a particular one of the n optical detectors is to detect a particular optical symbol of the transformed optical codeword, and to determine whether the particular optical symbol corresponds to a first optical symbol or a second optical symbol. The optical receiver may also include a decoder to construct a codeword based on the determinations, and to decode the constructed codeword into a message using the codebook. The optical receiver may attain superadditive capacity, and, with an optimal code, may attain the Holevo limit to reliable communication data rates.07-12-2012
20110255877DIGITAL COHERENT RECEIVER AND RECEIVING METHOD - A digital coherent receiver includes a front end, an A/D convertor, and a processor. The front end converts a light signal into an electric signal by using a signal light and a local oscillator light. The A/D convertor converts the electric signal of the front end into a digital signal. The processor calculates a spectrum gravity center of the digital signal converted by the A/D convertor, estimates a frequency offset of the digital signal based on the calculated spectrum gravity center, and reduces the frequency offset of the digital signal based on the estimated frequency offset.10-20-2011
20110255878BANDPASS COMPONENT DECIMATION AND TRANSMISSION OF DATA IN CABLE TELEVISION DIGITAL RETURN PATH - A device for and a method of decreasing the data rate of a digital return path link in a Cable Television Hybrid Fiber-Coax system (CATV system) is disclosed. At the node of the CATV system, the bandwidth of the a digital data stream representative of an analog return signal is limited to a desired frequency band. The ba10-20-2011
20110020012OPTICAL SIGNAL RECEIVING APPARATUS - A simple synchronizing detection circuit is provided in each of logical operation circuits, and a method for making a synchronizing detection in parallel is adopted. A selector control section monitors the states of the simple synchronizing detection circuits in parallel, and supplies an output from a proper logical operation circuit detecting the synchronization establishment to a frame synchronizing/terminating circuit at the latter stage. There is provided a function of relieving a synchronization determination condition if the synchronization establishment is not detected in any of the synchronizing detection circuits, whereby the output from the proper logical operation circuit can be selected depending on a load on a transmission path.01-27-2011
20110026938OPTICAL ROTARY JOINTS, METHODS OF MOUNTING SAME IN A PROPERLY-ALIGNED MANNER, AND OPTICAL RELECTOR ASSEMBLIES FOR USE THEREIN - The present invention relates generally to optical rotary joints (02-03-2011
20110110672Burst Mode Linear Optical Receivers - Techniques are provided for implementing a burst mode optical receiver capable of maintaining a stable gain profile in response to a burst signal. The optical receiver has a photodiode in balanced circuit configuration with a separate RF amplifier stage connected to each terminal of the photodiode. The two RF amplifier stages are coupled to biasing voltage sources that are inverted in comparison to the terminal connections and that, in some examples, each contain a field effect transistor (FET) that having a gate that is controlled in response to a sensed voltage. The burst mode optical receiver may be used in numerous applications, including optical line terminations (OLTs) in passive optical networks (PONs).05-12-2011
20110262149LIGHT RECEPTION DEVICE AND METHOD FOR CONTROLLING THE SAME - A light reception device includes: an interferometer that outputs a signal obtained by making an optical phase modulated signal interfere with a reference signal after shifting an optical phase of the optical phase modulated signal by a given amount; a light reception element that receives an output signal from the interferometer and converts the output signal into a light reception current; and a phase controller that controls a control amount in controlling the given amount so that a value of a function, which is calculated based on an amount relating to the light reception current and a change amount of an amount relating to the light reception current against the control amount, becomes an extreme value or 0.10-27-2011
20110135319OPTICAL ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING RECEIVER AND OPTICAL SIGNAL RECEIVING METHOD THEREOF - Provided is an optical OFDM receiver. The optical OFDM receiver receives an optical signal dependent on the nonlinearity of a transmitter. The optical OFDM receives includes an optical down converter, a nonlinearity compensator, and an OFDM demodulator. The optical down converter converts the optical signal into an electrical signal. The nonlinearity compensator filters the electrical signal, for compensating distortion which is added to the optical signal when the transmitter performs optical modulation. The OFDM demodulator demodulates the distortion-compensated electrical signal in an OFDM scheme.06-09-2011
20110052214METHOD AND APPARATUS FOR VISIBLE LIGHT COMMUNICATION WITH IMAGE PROCESSING - According to one embodiment, a visible-light communication apparatus includes an image input unit, a calculation unit, a preamble detection unit, a bit train detection unit, and a reception unit. The image input unit is configured to input image data generated by photographing a source of visible light carrying data. The calculation unit is configured to generate, from the image data, luminance data about an image at a designated position. The preamble detection unit is configured to detect a preamble at the head of the data, on the basis of the luminance data. The bit train detection unit is configured to detect the data bit train from the image data, in accordance with the preamble. The reception unit is configured to reproduce the data from the data bit train.03-03-2011
20110052213METHOD, APPARATUS AND SYSTEM FOR REDIRECTING INFRARED CONTROL CODES OVER A NETWORK FOR CONTROL AND PROCESSING - A networked bypass controller of the present invention receives IR codes transmitted from an IR transmitter (often a handheld device) and the controller is configured to either process the IR codes normally, or to perform actions, such as translation or association of the codes with stored function commands, on the IR codes transmitted. The networked bypass controller of the present invention can then send the resulting commands to one or more playout devices over a network to a device controller(s) for causing a response/change in an associated device(s).03-03-2011
20110052212Optical receiver - The present invention relates to an optical receiver, and particularly, to an optical receiver by which a DQPSK-modulated optical signal is demodulated to a multilevel phase-modulated signal.03-03-2011
20110217048Delayed interferometer and optical receiver - A delayed interferometer includes a branching unit that branches an optical signal into a first optical signal and a second optical signal; a guiding unit that guides the first optical signal in a first optical path to delay the first optical signal when a polarization direction of the first optical signal is the first direction, and guides the first optical signal in a second optical path when the polarization direction of the first optical signal is the second direction perpendicular to the first direction; a demodulating unit that causes the first optical signal guided in the first optical path or the second optical path and the second optical signal branched by the branching unit to interfere with each other, thereby demodulating the optical signal; and a polarization direction adjusting unit to adjust the polarization direction of the first optical signal in the first direction or the second direction.09-08-2011
20110110673Method and Apparatus for Coupling Optical Signal with Packaged Circuits Via Optical Cables and Lightguide Couplers - Method and apparatus for coupling electrical and communication circuits, included in a packaged semiconductor comprising photo receivers, photo transmitters and photovoltaic cells, through lightguide and optical fiber cables. The packaged semiconductor combinations comprise one, two or plurality of photo elements for a single or plurality one way optical signal, receive or transmit, and a single or plurality of two way optical signal communications via direct optical links and via optical prisms, filters, half mirrors and lenses. The packaged semiconductor includes at least one optical access to a single or plurality of lightguides or optical fiber with single core and for multicore lightguides. A built-in or attachable holders are used for attaching the different lightguide cables to the one or plurality of optical accesses with the attached cable end is terminated by cutting, trimming and shaping. The packaged circuit comprising electrical switches, current sensors, basic elements such as diodes, transistors and FETs, switches and power switches and different basic electrical circuit and communication, distribution circuits including CPU, DSP and complex semiconductor circuits, as used for communicating within limited short distances through optical network of lightguides and fiber optical cables. A packaged semiconductor of an SPDT power switch circuit is integrated with an SPDT manually activated switch, for providing dual switching for lights and other electrical appliances, via manual action and remotely via the lightguide or the optical fiber.05-12-2011
20120148264COHERENT OPTICAL RECEIVER FOR PILOT-ASSISTED DATA TRANSMISSION - A coherent optical receiver for a data-frame format in which a data frame has two or more pilot-symbol blocks, each having a cyclic prefix or suffix, and one or more payload-symbol blocks, each of which is concatenated with at least one adjacent block without a guard interval between them. The receiver uses optical signals corresponding to the pilot-symbol blocks to perform data-frame synchronization, frequency-offset correction, and channel-estimation procedures, which are robust even in the presence of certain transmission impairments. The receiver applies block-overlap processing with a sliding window to recover the payload data in a manner that substantially cancels the adverse effects of inter-block interference caused by the absence of guard intervals in the payload portion of the data frame. In one embodiment, the receiver performs channel-estimation and block-overlap processing for polarization-division-multiplexed signals in a manner that enables a combined, intertwined application of channel-response-compensation and polarization-demultiplexing procedures.06-14-2012
20110318021Feed-Forward Carrier Phase Recovery for Optical Communications - The carrier phase of a carrier wave modulated with information symbols is recovered with a multi-stage, feed-forward carrier phase recovery method. A series of digital signals corresponding to the information signals is received. For each digital signal, a coarse phase recovery is performed to determine a first phase angle which provides a first best estimate of the information symbol corresponding to the digital signal. Using the first best estimate as input, a second stage of estimation is then performed to determine a second phase angle which provides an improved (second) best estimate of the information symbol. Additional stages of estimation can be performed. The multi-stage, feed-forward carrier phase recovery method retains the same linewidth tolerance as a single-stage full blind phase search method; however, the required computational power is substantially reduced. The multi-stage, feed-forward carrier phase recovery method is highly efficient for M-QAM optical signals.12-29-2011
20110097092Optical Receiver Having Fractional Sampling - Apparatus and methods for receiving and processing optical signals carrying symbols that represent data, including an optical receiver having fractional sampling analog-to-digital conversion and interpolation timing recovery synchronization for processing an optical signal.04-28-2011
20120063789PHOTON DETECTOR - A photon detection system comprising: an avalanche photodiode; a biasing circuit configured to reverse bias said avalanche photodiode; a first measuring circuit configured to measure avalanche events occurring in said avalanche photodiode as a transient current due to photon absorption; and a second measuring circuit configured to measure the bias current flowing through the avalanche photodiode.03-15-2012
20120207484FREQUENCY SELECTIVE COMMUNICATIONS SYSTEM - A system and method are disclosed for a frequency selective communications system for sensing a sequence of multi-wavelength photons. The frequency selective communications system includes at least one intensity control device, at least one polarization control device, at least one focusing element, at least one frequency selective electromagnetic detector, and at least one processor. The frequency selective electromagnetic detector detects the sequence of photons. When the frequency selective electromagnetic detector senses a photon, the frequency selective electromagnetic detector emits an electrical pulse that has a voltage that is proportional to the energy level of the sensed photon. The processor processes the emitted electrical pulses, and de-multiplexes the sequence of emitted electrical pulses based on the voltage of the electrical pulses. In one or more embodiments, the frequency selective communications system is a frequency selective optical communications system that is used to sense photons having optical frequencies.08-16-2012
20090067854OPTICAL SPACE COMMUNICATION RECEPTION CIRCUIT, OPTICAL SPACE COMMUNICATION DEVICE, OPTICAL SPACE COMMUNICATION SYSTEM, AND ELECTRONIC DEVICE - An optical space communication reception circuit receives a signal in switched-over communication speed modes and under settings corresponding to the communication speed modes. Receiver sensitivity in the respective communication speed modes is set in advance such that maximum communicable distances in the communication speed modes are substantially equal. By this, it becomes possible, for example, in optical space transmission such as infrared communication and the like to enhance a false operation prevention characteristic against disturbance noise, without decreasing maximum communicable distances.03-12-2009
20090074426MONOLITHIC DQPSK RECEIVER - A monolithic, Indium Phosphide (InP) differential phase-shift keying (DPSK) or differential quadrature phase shift keying (DQPSK) receiver that exhibits low polarization sensitivity.03-19-2009
20090142075DQPSK optical receiver - According to an aspect of an embodiment, a DQPSK optical receiver, comprising: a first LPF connected to a line branching off from between a first optical-electrical converter and a first data recovery circuit; a second LPF connected to a line branching off from between a second optical-electrical converter and a second data recovery circuit; a first LIA for amplifying a signal output from the first LPF and also limiting an amplitude of an output signal thereof; a second LIA for amplifying a signal output from the second LPF and also limiting an amplitude of an output signal thereof; a first mixer for multiplying the output signal from the first LIA by a signal output from the second LPF; and a second mixer for multiplying the output signal from the second LIA by a signal output from the first LPF.06-04-2009
20110020013DEMODULATION OF AN OPTICAL CARRIER - A method of transmitting a plurality n data streams comprises modulating an optical carrier using differential M-ary phase shift key (DMPSK) signaling in which M=201-27-2011
20100054760Phase Detector Circuit for Clock and Data Recovery Circuit and Optical Communication Device Having the Same - A high-accuracy phase detector circuit compatible with a 1/N rate architecture is provided. The phase detector circuit has as many as N track-and-hold circuits for tracking and holding N-phase clock signals CLK03-04-2010
20100172656OPTICAL RECEIVER CIRCUIT AND OPTICAL COUPLING DEVICE - An optical receiver circuit and an optical coupling device, which includes: a light-receiving element; TIA operable to output a first voltage signal in response to input of the current signal; a voltage source operable to supply a second voltage signal serving as a reference voltage for determining pulse switching; a voltage source operable to supply a third voltage signal serving as a reference voltage for generating a shift control signal; a level shift circuit operable to output a voltage signal generated by subtracting a level shift voltage from the first voltage signal; a comparator operable to convert the first voltage signal to a pulse, and a controller operable to output the shift control signal outputting the first voltage signal shifted to a low-level side when the first voltage signal exceeds the third voltage signal, and outputting the first voltage signal without shifting after the output of the level shift circuit is lowered below the second voltage signal, are provided.07-08-2010
20120121273COMMON BASE CIRCUIT WITH OUTPUT COMPENSATION, CURRENT-TO-VOLTAGE CIRCUIT CONFIGURED WITH COMMON BASE AMPLIFIER, AND OPTICAL RECEIVER IMPLEMENTED WITH THE SAME - An amplifier implementing with a common base circuit is disclosed. The amplifier includes the common base circuit, a current shunt, and a current supplement. The common base circuit receives an input current. The current shunt shunts the input current based on the average of the output of the pre-amplifier. The current supplement supplements a current shunted by the current shunt.05-17-2012
20100209121SIGNAL PROCESSING DEVICE AND OPTICAL RECEIVING DEVICE - A signal processing device includes: a phase controller configured to control respective phases of an in-phase signal and an quadrature signal, which are obtained by converting an analog signal into a digital signal when a multi-value phase modulation light is demodulated, by digital signal processing; and a control amount provider configured to provide a control amount to the phase controller based on an output of the phase controller.08-19-2010
20120134684Adaptive equalizer, optical receiver, and tap coefficient correcting method - An adaptive equalizer includes a finite impulse response filter with a predetermined number of taps; and a tap coefficient adaptive controller having a register to hold tap coefficients for the filter, a weighted center calculator to calculate a weighted center of the tap coefficients, and a tap coefficient shifter to shift the tap coefficients based on a calculation result of the weighted center. During an initial training period, the tap coefficient shifter shifts the tap coefficients on a symbol data basis such that a difference between the calculated weighted center of the tap coefficients and a tap center defined by the number of taps is minimized.05-31-2012
20120213531ULTRA-HIGH-SPEED PHOTONIC-ENABLED ADC BASED ON MULTI-PHASE INTERFEROMETRY - A ultra high speed photonic Analog to Digital Converted (ADC) for sampling and quantizing an electrical voltage signal, internally enabled by photonics uses coherent optical detection architectures for photonic quantization. Coherent light is phase modulated by the test signal. Using an interferometer, or an array of interferometers the phase of modulated light is compared with a reference light. Flash ADC, successive approximation ADC and delta-sigma ADC configurations are presented.08-23-2012
20120315052INPUT ISOLATION OF A TRANSIMPEDANCE AMPLIFIER IN OPTICAL RECEIVERS - An optical receiver is described. This optical receiver has two operating modes: a calibration mode and a normal mode. During the normal mode, switches are used to electrically couple an input of a transimpedance amplifier (TIA) to an optical-to-electrical (OE) converter that receives an optical signal and provides a corresponding analog electrical signal. Moreover, during the calibration mode, the switches are used to electrically isolate the input of the TIA from the OE converter while maintaining a feedback path from an output of the TIA to the input of the TIA, thereby ensuring proper bias of the TIA during calibration. Furthermore, a frequency response of the TIA during the normal mode is substantially unchanged over an operating bandwidth of the TIA by the capability to electrically isolate the input of the TIA from the OE converter during the calibration mode.12-13-2012
20120170947APPARATUS AND METHOD FOR RECEIVING LIGHT USING MULTIPLE LIGHT RECEIVING SENSORS - In an apparatus and method for receiving light using multiple light receiving sensors, a light receiving apparatus includes a light receiving unit comprising multiple light receiving sensors to receive an optical signal; an analyzing unit to extract a highlighted area; a light receiving controlling unit to activate a first light receiving sensor corresponding to the highlighted area, and to determine the first light receiving sensor to be a part of a first sensor group; and a data processing unit to demodulate an optical signal received by the first sensor group into data. A method for receiving an optical signal including extracting a highlighted area; activating a light receiving sensor corresponding to the highlighted area; receiving light through the first light receiving sensor; grouping the first light receiving sensor into a first sensor group; and demodulating an optical signal received by the first sensor group into data.07-05-2012
20120076506COHERENT OPTICAL RECEIVING APPARATUS AND COHERENT OPTICAL RECEIVING METHOD - A coherent optical receiving apparatus according to the present invention includes a coherent optical receiving unit to receive a whole of an optical multiplexed signal into which an optical signal is multiplexed, a tunable filter, a local oscillation unit, and a control unit. The coherent optical receiving unit, which includes a 90-degree hybrid circuit and an optoelectric conversion device, selectively detects an optical signal, which interferes with a local oscillation light outputted by the local oscillation unit, out of the optical multiplexed signal. The tunable filter, which is arranged in front of the optoelectric conversion device on an optical path on which the optical multiplexed signal flows, has a bandwidth within which a plurality of optical signals are included. The control unit makes a central wavelength of the tunable filter and a wavelength of the local oscillation light be changed together.03-29-2012
20120177384SCALABLE WAVEGUIDE-MODE COUPLER FOR AN OPTICAL RECEIVER OR TRANSMITTER - A waveguide-mode (WM) coupler having a plurality of single-mode fibers, each optically coupled to a different respective waveguide mode of a multimode fiber. The coupling optics employed by the WM coupler are scalable and include reflective fiber-tip coatings, polarization beam splitters, phase masks, and quarter-wave plates configured to overlap and/or separate the optical beams corresponding to different waveguide modes of the multimode fiber in a manner that does not cause a significant increase in the optical insertion losses with an increase in the number of optical channels in the WM coupler.07-12-2012
20080298815Small Form Pluggable Analog Optical Receiver - A pluggable small form factor optical receiver is described. The optical receiver can be plugged into an optical receiver unit which may hold many optical receivers. The optical receiver includes a photo-detector, a pre-amplification stage, and an attenuator. The optical receiver may have receptacle optical ports such as LC or SC type, also it may include a pin connector for mating with the optical receiver unit and a latch mechanism to secure the optical receiver in the optical receiver unit.12-04-2008
20120269523OPTICAL DIFFERENTIAL PHASE-SHIFT KEYED SIGNAL DEMODULATOR - A phase-shift keyed signal demodulator and method for demodulating is disclosed. An example demodulator includes N filters that receive inputs from a splitter and include transmission functions offset from one another. N pairs of photodiodes receive the transmitted and reflected beams from each filter and a decoder converts the outputs of the pairs of photodiodes to one or more data symbols.10-25-2012
20090257757SIGNAL IDENTIFICATION IN OPTICAL COMMUNICATIONS NETWORKS - Signals in an optical communications network, such as optical channels in an optical WDM network for example, are each identified by at least two low frequency dither tones with which the signal is modulated. The dither tones alternate with a predetermined periodicity to produce a cyclically repeated sequence of dither tones. A network parameter, such as a channel identifier for example, is obtained by the detection of the particular combination of dither tones in the sequence. To detect a number of network parameters a signal is modulated with a number of cyclically repeated sequences of dither tones each uniquely identifying a respective network parameter. In some implementations each dither tone in a cyclically repeated sequence of dither tones is repeated with substantially the same phase and coherent averaging is performed over a number of periods to detect dither tones on low power signals.10-15-2009
20100232810Electromagnetic device with integral/non-linear component - An optical antenna assembly including multiple optical antenna elements, each of the optical antenna elements are arranged in a regular pattern and carried by a supporting body. The regular pattern of the plurality of optical antenna elements is nonuniform. Certain ones of the optical antenna elements are configured to respond to the one or more waves of light.09-16-2010
20100232809Detection of Data in Signals with Data Pattern Dependent Signal Distortion - A detection system and method may be used to detect data transmitted in a signal with data pattern dependent signal distortion. In general, a detection system and method compares samples of a received signal with stored samples of distorted signals associated with known data patterns and selects the known data patterns that correspond most closely with the samples of the received signal. The detection system and method may thus mitigate the effects of data pattern dependent signal distortion.09-16-2010
20100232808RECEIVING CIRCUIT FOR OPTICAL COMMUNICATION - A receiving circuit for optical communication includes: a differential circuit, one differential input terminal of which is connected to an anode side of a first photodiode and the other differential input terminal of which is connected to an anode side of a second photodiode; a latch circuit that performs latch operation based on output of the differential circuit; and a flip-flop that performs set operation and reset operation based on a latch state of the latch circuit.09-16-2010
20120087678OPTO-ELECTRONIC ASSEMBLY FOR A LINE CARD - In one embodiment, the opto-electronic assembly is a hybrid integrated circuit having an array of avalanche photodiodes (APDs) that are electrically coupled to a corresponding array of transimpedance amplifiers (TIAs), with both the APDs and TIAs being mounted on a common ceramic substrate. The opto-electronic assembly further has an optical subassembly comprising an arrayed waveguide grating (AWG) and an array of turning mirrors, both attached to a temperature-control unit in a side-by-side arrangement and flip-chip mounted on the substrate over the APDs. The opto-electronic assembly employs a silicon-based submount inserted between the APDs and the substrate to accommodate the height difference between the APDs and the TIAs. The submount advantageously enables the placement of APDs in relatively close proximity to the turning mirrors while providing good control of the APD's tilt and offset distance with respect to the substrate. The temperature-control unit enables independent temperature control of the AWG and of the array of turning mirrors, which helps to achieve good optical-coupling efficiency between the AWG and the APDs even when the turning mirrors have a relatively small size.04-12-2012
20120321325PARALLEL CONVERSION BETWEEN OPTICAL AND DIGITAL - A coherent optical receiver Includes an electro-optic module coupled to an electronic signal processing Integrated circuit (IC) via a parallel analog transmission line bus. The electro-optic module receives and detects an optical channel light including a high-bandwidth signal modulated thereon. The electro-optic module includes: a single optical hybrid for mixing the optical channel light with a corresponding continuous wave local oscillator light to generate a mixed light containing the high-bandwidth data signal, at least one photodetector; and an analog frequency decimator for generating a set of parallel analog signals, each analog signal representing a respective portion of the high-bandwidth signal. The electronic signal processing IC includes a respective Analog-to-digital (A/D) converter for sampling each one of the set of parallel analog signals, and for generating corresponding parallel digital sample streams; and a digital signal processor (DSP) for processing the parallel digital sample streams to extract the high-bandwidth signal.12-20-2012
20120328305FORWARD CARRIER RECOVERY USING FORWARD ERROR CORRECTION (FEC) FEEDBACK - A system receive, from an optical receiver, a signal derived from a first optical signal and a second optical signal generated by a local oscillator, that includes a first component that is an in-phase component and a second component that is a quadrature phase component; filter the signal, using a filter, set to one or more configurations, to obtain one or more recovered signals, where each of the recovered signals includes a respective quantity of noise; perform forward error correction, on the recovered signals, to obtain one or more quantities of bit errors that correspond to the recovered signals; and process the signal using the filter set to a particular configuration, of the one or more configurations, that corresponds to a lowest quantity of bit errors of the one or more quantities of bit error.12-27-2012
20090208226Bang-bang architecture - In one embodiment, the present invention includes an apparatus having a voltage controlled oscillator (VCO) to generate a first clock signal having a frequency controlled by a bias current coupling ratio of first and second bias currents, and a control circuit coupled to the VCO to generate a first pair of control signals to adjust the bias current coupling ratio. Other embodiments are described and claimed.08-20-2009
20110158656HIGH DYNAMIC RANGE APD OPTICAL RECEIVER FOR ANALOG APPLICATIONS - An optical receiver includes a light receiving element such as an avalanche photodiode (APD) for converting an optical signal to an electrical photocurrent amplified by a first current gain value and a temperature sensor for measuring the temperature of the light receiving element. The optical receiver also includes a control unit configured to control a bias voltage applied to the light receiving element such that the first gain value is adjusted to a second gain value based at least in part on a predetermined relationship between the current gain, the temperature and the applied bias voltage. The second current gain value is based at least in part on one or more parameters characteristic of the optical receiver and a system in which the optical receiver is employed.06-30-2011
20080253776Optical Signal Receiver - An optical signal receiver is provided for converting an optical signal being intensity-modulated with high frequency signals, to desired frequency electric signals for output. The optical signal receiver (10-16-2008
20080240739Differential circuit with precisely controlled terminator circuit - The present invention provides a precisely controlled terminator circuit of a differential amplifier, in particular, for a differential amplifier of an optical receiver. The differential circuit, which receives a differential signal by a first input for the normal phase signal and a second input for an anti-phase signal, provides a terminator circuit comprises two resistors connected in serial between two inputs and two resistive connections each including a transistor and a resistor serially connected to the transistor and connected between respective inputs and the power supply line Vcc. The control unit, by receiving a medium potential of two resistors, provides a bias to two transistors so as to equalize the medium potential with the reference potential.10-02-2008
20080240737OPTICAL RECEIVER AND CONTROL METHOD FOR OPTICAL RECEIVER - An optical receiver converting an optical signal modulated by differential phase shift keying to electrical first and second data signals; generating a clock signal from the first data signal; demultiplexing the first data signal into two signals; latching the two signals using the clock signal; delaying the clock signal by a certain amount; latching the two signals using the delayed clock signal; demultiplexing the second data signal into two additional signals; generating an inverted clock signal by inverting the clock signal; latching the two additional signals using the inverted clock signal or the clock signal; and further latching the two additional signals using the delayed clock signal.10-02-2008
20080232822Optical receiver - The present invention provides an optical receiver that suppresses the saturation in the output without alleviating the bandwidth restriction of the current-to-voltage conversion gain. This optical receiver comprises an amplifier 09-25-2008
20080226307Methods and systems for monitoring multiple optical signals from a single source - Methods and systems for monitoring a plurality of different optical signals from a single source of such signals, where each such different optical signal is spatially separated from other such signals and directed to different detectors or locations upon a single detector, which direction is generally accomplished through the use of a small number of optical components and/or manipulations.09-18-2008
20080226306GT decoder having bandwidth control for ISI compensation - An optical receiver apparatus and methods for mitigating intersymbol interference (ISI) in a differentially-encoded modulation transmission system by controlling constructive and destructive transfer functions. The receiver includes a bandwidth control element for controlling transfer function bandwidth, a transfer phase controller for controlling transfer function phase and/or an imbalancer for imbalancing the transfer functions for compensating for intersymbol interference and optimizing the quality of the received optical signal.09-18-2008
20090196632OPTICAL BURST RECEIVER AND METHOD - The present invention allows a configuration with elements inside the LSI, the elimination of manpower by using automatic adjustment, a reduction in the manufacturing cost, and control of the duty ratio in a wide temperature range and a wide dynamic range and includes: a TIA that converts an optical burst signal from a current signal to a voltage signal and that outputs the voltage signal as a differential signal; a peak detection/adder circuit that detects a peaking preamble signal of the differential signal, sets the peaking level to a normal phase and a reversed phase, and adjusts an offset signal; an ATCBUFFER that controls the duty ratio of the output signal by a threshold voltage; a duty detection circuit that detects the duty ratio from a burst signal; a threshold voltage adjustment circuit that adjusts the duty ratio by a new threshold voltage in accordance with the size of the voltage signal corresponding to the duty ratio; and a reset control circuit that can detect a burst signal of the duty detection circuit by a reset signal that confirms the arrival of the burst signal.08-06-2009
20090041477ATTENUATION SYSTEMS AND METHODS FOR USE WITH AN OPTICAL DETECTOR IN AN OPTICAL COMMUNICATION SYSTEM - Systems and methods for use with an optical communication beam are disclosed. The system allows the beam of light to operate at an adequate power level that provides a robust optical link while minimizing any safety risk to humans. The system calibrates and controls the gain for an avalanche photodiode detector (APD). A detector circuit is used to calibrate the APD. Once calibrated, the detector circuit further provides an electrical bias to the APD to process or condition the electrical signal to produce a detector output. The systems and methods disclosed herein attenuate the power level of an incoming communication beam to prevent oversaturation of an APD. The system further provides an alignment signal, which is effective over a wide dynamic range of incoming power levels.02-12-2009
20120281989OPTICAL RECEIVER - An optical receiver including a photo detector for converting a light signal into an electrical current signal and a preamplifier circuit for receiving the electrical current signal and outputting a corresponding voltage signal. In one example, the preamplifier circuit includes a first transistor having: (i) a high impedance node connected to an input node connected to receive the electrical current signal from the photo detector, and (ii) a control terminal connected to receive active negative feedback proportional to the electrical current signal received at the input node.11-08-2012
20110158657INFRARED RECEIVER CIRCUIT - The invention relates to an infrared receiver circuit for processing a carrier-modulated infrared signal, comprising an amplification circuit and a demodulator. A comparator is provided, which is designed to digitize the output signal of the amplification circuit or of a band pass filter connected downstream of the amplification circuit by comparison to a threshold value in order to create a pulse train signal. The receiver circuit comprises a logic circuit, which is designed to link the pulse train signal of the comparator and the output signal of the demodulator logically to each other in order to extract an additional output signal corresponding to the infrared signal from the pulse train signal.06-30-2011
20120020677RECEIVING DEVICE AND DEMODULATION DEVICE - To adequately perform sampling, a receiving device that solves problems that involve an increase in circuit area and an increase in cost, is provided.01-26-2012
20120020676APPARATUS FOR RECEIVING OPTICAL SIGNAL AND METHOD OF CONTROLLING PHASE OFFSET FOR DIFFERENTIAL QUADRATURE PHASE SHIFT KEYING - An apparatus for receiving optical signals in DQPSK and method of controlling a phase offset in receiving optical signals for DQPSK is provided. An original optical signal modulated in DQPSK is received. The original optical signal is delayed by one bit to make a delay optical signal such that an interference on the original optical signal and the delay optical signal is performed. A control signal is generated by use of an interference result between the original optical signal and the delay optical signal. A phase offset for the interference between the original optical signal and the delay optical signal is controlled by use of the generated control signal. In receiving optical signals, the phase offset between the delay optical signal and the original optical signal is precisely controlled, thereby optimizing the transfer characteristics of an optical delay interferometer.01-26-2012
20120033980Burst Optical Signal Receiving Device - A burst optical signal receiving device is provided, which includes an optical receiving component and a limiting amplifying circuit unit. The optical receiving component further includes a photodetector, a trans-impedance amplifier, a first direct current (DC) cancellation forbidding circuit, and a DC bias circuit, and the limiting amplifying circuit unit further includes a group of alternating current (AC) coupling capacitors, a limiting amplifier, and a second DC cancellation forbidding circuit. Through the technical solution, an input burst optical signal within a certain dynamic range can be recovered into a valid burst electric signal in shorter time. The technical solution can be applied in a burst optical signal receiver in a 10-Gigabit Ethernet passive optical network (10GEPON).02-09-2012
20080240735Symmetrical Optical Receiver - The invention relates to a symmetrical optical receiver comprising a photodiode (Ph) and a symmetrical transimpedance amplifier (TIA). The cathode (K) or respectively the anode (A) of the photodiode (Ph) is connected via a first capacitor (C10-02-2008
20090214226OPTICAL DQPSK RECEIVER AND OPTICAL PHASE MONITOR APPARATUS FOR USE IN OPTICAL DQPSK RECEIVER - First and second delay interferometers respectively have a phase-shift element. First and second photo detectors respectively detect optical signals output from the first and second delay interferometers. First and second data recovery circuits recover data from signals detected by the first and second photo detectors, respectively. A common adjustment unit adjusts the phase-shift elements of both first and second delay interferometers in accordance with an output signal from the first photo detector and an output signal from the second data recovery circuit. An individual adjustment unit adjusts the phase-shift element of the second delay interferometer in accordance with the output signal from the first photo detector and an output signal from the second photo detector.08-27-2009
20130094866Wearable accessory for monitoring whether user is looking at portable electronic device - An accessory that includes a light transmitter may be worn by a user of an electronic device that includes a light receiver and a display screen. When the accessory is paired to the electronic device, the device may be configured to perform one or more behaviors in response to a change intensity of light incident on the light receiver, the light having been transmitted from the accessory. Example behaviors include activating and deactivating the display screen, altering what is displayed on a display screen, and turning the electronic device on or off. The device may also be configured to determine one or more properties of the light incident on the light receiver and to perform the behaviors only if the one or more properties correspond to one or more prerequisite light properties stored in the device.04-18-2013

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