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Having particular modulation

Subclass of:

398 - Optical communications

398182000 - TRANSMITTER

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Class / Patent application numberDescriptionNumber of patent applications / Date published
398188000 Phase modulation 39
398186000 Intensity modulation 23
398185000 Hybrid modulation 20
398184000 Including polarization 19
398187000 Frequency modulation 15
398189000 Pulse modulation 7
20120183306OPTICAL TRANSMITTER INCLUDING EA MODULATOR AND DRIVER - An optical transmitter to drive the EA modulator integrated with an LD in a mode of lowered power consumption. The optical transmitter includes the optical device integrating the LD with the EA modulator, and the driver to modulate the EA modulator in the differential mode by being supplied with the modulation signal between the anode and the cathode common to the LD.07-19-2012
20100104294Optical modulation device - The present invention discloses an optical modulation device, which comprises an electric signal generator generating an electric signal carrying a data signal; a first sinusoidal signal generator generating a first sinusoidal signal; an optical signal generator generating an input source optical signal; and an optoelectronic modulator(Mach-Zehnder modulator) receiving the input source optical signal, the electric signal and the first sinusoidal signal, biased to modify a transmission performance of the input source optical signal, modulating the input source optical signal with the electric signal and the first sinusoidal signal, and then sending out an output source optical signal carrying the electric signal and the first sinusoidal signal. The present invention realizes frequency multiplication, enables an optical signal to carry vector signals, and promotes the efficiency of broadband systems.04-29-2010
20130084078Technique for Increasing Signal Gain - A technique for generating complementary signals for joint transmission involves generating a first signal having a first wavelength and a second signal having a second wavelength. The first signal is modulated with a first modulation to encode data, and the second signal is modulated with a second modulation, which is an inverted version of the first modulation, to encode the same data such that the first and second signals are complementary. The first and second signals are combined to produce a combined signal in which power attributable to the first signal is interleaved with and substantially non-overlapping temporally with power attributable to the second signal. The combined signal is amplified and then transmitted. The first and second signals can be optical signals at respective first and second optical wavelengths, where the first and second signals are on-off keying (OOK) modulated.04-04-2013
20100142976TRANSMITTING CIRCUIT AND COMPLEMENTARY OPTICAL WIRING SYSTEM - A transmitting circuit has a first transmitter configured to generate a first electric pulse signal in synchronization with a rising edge of a digital electric input signal, a second transmitter configured to generate a second electric pulse signal in synchronization with a falling edge of the digital electric input signal, a first variable impedance circuit configured to supply a bias current to a first light-emitting element only for a predetermined period before the first light-emitting element for converting the first electric pulse signal into a first light signal is supplied with the first electric pulse signal, and a second variable impedance circuit configured to supply a bias current to a second light-emitting element only for a predetermined period before the second light-emitting element for converting the second electric pulse signal into a second light signal is supplied with the second electric pulse signal.06-10-2010
20110002697METHOD AND APPARATUS FOR OPTICAL SIGNAL POWER DISCRIMINATION - The present invention provides an optical power level discriminating device and method for discriminating optical power levels. The optical discriminating device includes a splitter for receiving an optical signal having first and second signal states, and splitting the received optical signal into a first and a second branch optical signal. A first optical fiber for transporting the first branch optical signal is provided that is made of a material having a high non-linear refractive index providing a different non-linear phase shift to the first and second signal states of the first branch optical signal. A second optical fiber is provided for transporting the second branch optical signal with little or no non-linear effect. The discriminating device also includes a combiner for combining the first branch optical signal and second branch optical signal to produce an output optical signal. The output signal is resulted from a constructive interference between the first signal states of the first and second branch optical signals, and a destructive interference between the second signal states of the first and second branch optical signals.01-06-2011
20090041470Multi-wavelength signal generation device and multi -wavelength light generation method - It is an object of the present invention to provide a multiple wavelength signal generation device capable of generating lights of more wavelengths, and a generation method for multiple wavelength light using a multiple wavelength signal generation device.02-12-2009
20120224865PHASE LOCKED LOOP - An optical phase-locked loop (OPLL) comprising a phase-frequency detector; first and second lasers; a local oscillator; a detector and a low pass filter; operably connected in a circuit comprising a feedback path. The OPLL can also include a pre-scaler, a second local oscillator and a mixer.09-06-2012
20090232517DITHERLESS OPTICAL MODULATOR CONTROL - A method of controlling the operating parameters of an optical modulator, without using a dither signal, is provided. Past operating parameters are compared to present operating parameters using a quality of modulation signal obtained by cross-correlating the data modulation signal used to drive the optical modulator with the modulated optical signal output from the optical modulator. The quality of modulation signal is used to optimize the operating parameters (e.g., bias point) of the optical modulator, or other operating parameters of the arrangement, such as the modulator drive level, timing alignment, etc.09-17-2009
20110129232EXTERNAL MODULATOR MONITORING DEVICE AND EXTERNAL MODULATOR MONITORING METHOD - This invention relates to external modulator monitoring device and method for monitoring an external modulator. The external modulator monitoring device includes a mixing unit for mixing optical signals modulated by the external modulator and optical signals not modulated by the external modulator, so as to obtain multiple branches of mixed optical signals; an electrical differential unit for converting the multiple branches of mixed optical signals into corresponding multiple branches of electrical signals, and performing a differential processing on voltages of the multiple branches of electrical signals to obtain differential signals; and a power detection unit for detecting power of the differential signals.06-02-2011
20090087196METHOD AND SYSTEM FOR SPLIT VOLTAGE DOMAIN TRANSMITTER CIRCUITS - Methods and systems for split voltage domain transmitter circuits are disclosed and may include amplifying a received signal in a plurality of partial voltage domains. Each of the partial voltage domains may be offset by a DC voltage from the other partial voltage domains. A sum of the plurality of partial domains may be equal to a supply voltage of the integrated circuit. A series of diodes may be driven in differential mode via the amplified signals. An optical signal may be modulated via the diodes, which may be integrated in a Mach-Zehnder or a ring modulator. The amplified signals may be communicated to the diodes, connected in a distributed configuration, via even-mode coupled transmission lines. The partial voltage domains may be generated via stacked source follower or emitter follower circuits. The voltage domain boundary value may be at one half the supply voltage due to symmetric stacked circuits.04-02-2009
20110299858HOST DEVICE WITH MULTIPURPOSE OPTICS DRIVE CAPABILITIES - A host device is provided that can leverage multiple optical modulation scheme capabilities of the optical module. The host device comprises an electrical modulator unit configured to generate electrical transmit signals comprising modulated data in a modulation format, and a connector configured to connect to the optical module that transmits optical signals to an optical fiber. The host device comprises a controller that is configured to select one of a plurality of optical modulation schemes for an optical reach, and to generate a control signal for supply to the optical module via the connector. The control signal is configured to cause the optical module to generate optical signals from the electrical transmit signals according to the selected optical modulation scheme.12-08-2011
20090123163METHOD OF PRODUCING A HIGHLY PERMEABLE STABLE RF WAVEFRONT SUITABLE AS A DATA CARRIER - A method for generating a highly permeable stable broadband wavefront includes generating a modulated photon wave associated with a modulated data signal, the modulated photon wave comprising plural energized particles, directing the modulated photon wave to an incident surface of a charge transformer and transforming the plural energized particles within the charge transformer. The transformed particles are at substantially zero charge. The method also includes generating a wavefront at an exit surface of the charge transformer including the transformed particles at substantially zero charge.05-14-2009
20090123162CONTROLLER FOR OPTICAL TRANSMISSION DEVICE - A controller supplies a driving signal to an optical modulator for modulating light from a light source in accordance with the driving signal, a low frequency signal being superposed on the driving signal. A bias unit monitors a low frequency component of the modulated light and controls bias of the optical modulator. A compensation unit controls the intensity of the light so as to compensate for refractive index variation of the optical modulator which is caused by variation of the bias.05-14-2009
20090041471REMODULATING CHANNEL SELECTORS FOR WDM OPTICAL COMMUNICATION SYSTEMS - The present invention provides a remodulating channel selector for a wavelength division multiplexed optical communication system. The remodulating selector receives a WDM input signal, selects a particular optical channel from the WDM signal and places the information from the selected signal onto a newly-generated optical output signal. The wavelength of the output optical signal can be the same as or different from one of the optical channels which comprises the WDM input signal. When used in a WDM optical communication system with remodulators at the transmission input, the remodulating selectors provide complete control over the interfaces with optical transmitters and receivers, permitting use with a broad range of optical equipment.02-12-2009
20090274470Optical Code Communication System - An optical code communication system comprises an optical transmitter, an optical receiver, and an optical transmission line. The optical receiver has an optical mixing decoder for mixing a coded light and a local light, dividing the mixed light into an object optical frequency and a non-object optical frequency, and outputting the lights and a detection adder-subtractor filter for detecting the object optical frequency and the non-object optical frequency, filtering the intermediate frequency signals, subtracting one of the intermediate frequency signal from the other, and outputting the resultant intermediate frequency signal. The coded light and the local light are coherent with each other between the optical frequency chips constituting the coded light when detected. The optical mixing decoder or detection adder-subtractor filter regulates the phase of the intermediate frequency signal within the passband when filtered so that the output value or the absolute value of the intermediate frequency signal within the passband when filtered is different when the optical receiver receives a coded light modulated with a different value of the transmission data.11-05-2009
20120294627OPTICAL MODULATION METHOD AND SYSTEM - The present invention provides an optical modulation method and system. The method includes: loading a first dither signal on an amplitude of an input data signal; loading a second dither signal on a bias voltage; and according to the bias voltage loaded with the second dither signal, obtaining a modulation signal according to the data signal whose amplitude is loaded with the first dither signal, and outputting the modulation signal as an output optical signal, where the first dither signal and the second dither signal are signals of the same frequency and the same phase, and a ratio of amplitudes of the signals is determined according to a tracking error, so that a feedback signal obtained according to the modulation signal is locked to a required bias point. In the embodiments of the present invention, lock precision may be improved.11-22-2012
20080212979OPTICAL TRANSMITTER AND OPTICAL TRANSMISSION CONTROL METHOD - An exemplary aspect of the invention is an optical transmitter that emits a light signal, including: a light source; a Mach-Zehnder optical modulator; a modulator driver; a wavelength information holder; and a driving voltage controller, wherein the Mach-Zehnder optical modulator modulates the light intensity of output light from the light source by use of a modulator driving signal, the modulator driver outputs the modulator driving signal according to an input data signal, the wavelength information holder holds wavelength information on the output light of the light source, the driving voltage controller outputs, to the modulator driver, a control signal for setting the latest driving voltage, according to the wavelength information from the wavelength information holder.09-04-2008
20080240732OPTICAL COMMUNICATION MODULE AND CONTROL METHOD THEREOF - An optical communication module includes a driving unit, an optical transmitting unit, a control unit and a signal transform control unit. The driving unit outputs a bias signal and a modulation signal in accordance with a bias control signal and a modulation control signal. The optical transmitting unit is electrically connected to the driving unit, outputs an optical signal in accordance with the bias signal and the modulation signal, and generates a feedback signal. The signal transform control unit is electrically connected to the driving unit and generates the bias control signal and the modulation control signal to be inputted to the driving unit. The control unit is electrically connected to the optical transmitting unit and the signal transform control unit, and controls the signal transform control unit in accordance with the feedback signal. A control method of the optical communication module is also disclosed.10-02-2008
20080232820Optical Vector Modulator - An optical vector modulator includes an information generator that generates a plurality of N-bit streams at an output where each of the plurality of N-bit streams represents a desired modulation point in a signaling constellation. A memory look-up table having an N-bit address input retrieves a first and a second stored value that corresponds to the N-bit address input, where each of the first and the second stored value represent a respective one of a first and a second modulation vector of a desired modulation point in the signaling constellation. A first and a second digital-to-analog converter generates first and second analog signals, respectively, that correspond to respective ones of the first and second modulation vectors of the desired modulation points in the signaling constellation. A dual-drive interferometric modulator modulates the first and the second analog signals on the optical beam to obtain the desired modulation points in the signaling constellation.09-25-2008
20080226305INTEGRATED OPTICAL WAVEFORM MODULATOR - A method of modulating an optical carrier. A target carrier modulation is computed based on an input data signal. An effective length of an optical modulator is then controlled based on the target carrier modulation.09-18-2008
20090136240Balanced Phase-Shaped Binary Transmission In Optical Communications - Optical communication apparatus, methods, systems are provided based on balanced-detection phase-shaped binary transmission (BD-PSBT).05-28-2009
20090080904Optical transmitting apparatus and setting-value determining method - A wavelength-variable light source generates light having a wavelength according to an input wavelength control current. An EA modulator modulates light generated by the wavelength-variable light source, based on a modulation characteristic corresponding to an input EA bias. A TEC changes the temperature of the wavelength-variable light source and that of the EA modulator according to an input temperature control current. A control unit adjusts the setting-value of the wavelength control current input to the wavelength-variable light source, the setting-value of the EA bias input to the EA modulator, and the setting-value of the temperature of the EA modulator according to input wavelength data.03-26-2009
20110229148OPTICAL MODULATION APPARATUS AND OPTICAL MODULATION METHOD - An optical modulation apparatus includes a first modulator, a second modulator, a multiplexer, a detector and an adjustor. The first modulator modulates light emitted by a light source using a first input signal and outputs a first modulated signal. The second modulator modulates the light using a second input signal and outputs a second modulated signal. The multiplexer multiplexes the first and second modulated signals and outputs a multiplexed signal. The detector is configured to detect a dip where power in a waveform of the multiplexed signal is equal to or smaller than a predetermined value. The adjustor is configured to adjust a delay of the first and second input signals based on power at the dip.09-22-2011
20090220248Embedded Parametric Monitoring of Optoelectronic Modules - An optoelectronic module for converting and coupling an information-containing electrical signal with an optical fiber including a housing having an electrical input for coupling with an external electrical cable or information system device and for transmitting and receiving information-containing electrical signals over such input, and a fiber optic connector adapted for coupling with an external optical fiber for transmitting and receiving an optical signal; an electro-optic subassembly coupled to the information containing electrical signal and converting it to and/or from a modulated optical signal corresponding to the electrical signal; and parametric storage means disposed in said housing for storing environmental and/or operational data associated with the module, and an optional method for time-biased lossy compression of such stored data.09-03-2009
20090252500Optical Modulator - It is an object of the invention to provide an optical modulator in which a connection substrate or a terminal substrate is disposed outside an optical modulation element and which can maintain at a proper voltage amplitude value a modulation signal applied to an optical modulation element. An optical modulator includes: a substrate having electro-optic effect; an optical waveguide formed on the substrate; an optical modulation element 10-08-2009
20100003036Communication apparatus and signal reception method - A communication apparatus in accordance with an embodiment comprises a reception unit configured to demodulate a received signal to output a first demodulated signal in dependence on a reception condition. The communication apparatus further comprises a pattern detection unit configured to detect a characteristic pattern in the first demodulated signal to output a pattern detection signal, and a pitch detection unit configured to detect a pitch of the characteristic pattern based on the pattern detection signal to output a first signal detection signal indicating that the first demodulated signal is one of an in-phase signal and a quadrature signal, or an inverted version of the one of the in-phase signal and the quadrature signal.01-07-2010
20100178064OPTICAL DEVICE AND OPTICAL TRANSMITTER - An optical device and an optical transmitter are provided. The optical device includes a substrate, a first optical waveguide that may be formed in the substrate and may have a bending portion, and a second optical waveguide that intersects with the bending portion of the first optical waveguide, wherein a groove may be formed outside the bending portion of the first optical waveguide in the substrate.07-15-2010
20100254714DATA TRANSMISSION WITH ROOM ILLUMINATIONS HAVING LIGHT EMITTING DIODES - Lamps having light emitting diodes configured for data transmission require the high-frequency circuit of higher power. In order to simplify the required electronics, the light emitting diodes are divided into groups and the groups are modulated differently. Due to the multilevel modulation, the symbol rate can be reduced with the data rate remaining the same, thus reducing the switching rate and the circuitry complexity.10-07-2010
20100135673APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING AN INFORMATION SYMBOL IN A VISIBLE LIGHT COMMUNICATION SYSTEM FOR COLOR CODE MODULATION - A visible light communication system and method for transmitting and receiving an information symbol in a visible light communication system for a Color Code Modulation (CCM) scheme using a chromaticity diagram. The method includes determining a first coordinates value corresponding to an information symbol to be transmitted on the chromaticity diagram; determining a first color ratio corresponding to the first coordinates value; determining a second coordinates value corresponding to a compensation symbol for compensating for the first color ratio into a color white and determining a second color ratio corresponding to the second coordinates value; and emitting a visible ray corresponding to each of the first color ratio and second color ratio. The first and second coordinates values are located on a line on the chromaticity diagram.06-03-2010
20090067852Optical modulator and optical transmitter - A reduction in size and cost of an optical modulator is achieved with a simple configuration, while improving the modulation characteristics. An optical modulator modulates light branched by an optical coupler and then couples the light via the optical coupler. The optical coupler is formed in a substrate having electro-optic effects. An optical waveguide is formed in the substrate and, includes a turnback section and ends into which the light branched by the optical coupler is input. A signal electrode is provided in the substrate along the optical waveguide. A modulation signal to modulate the light passing through the optical waveguide is input to the signal electrode.03-12-2009
20110033192Small Packaged Tunable Optical Transmitter - According to one embodiment, the present application includes a tunable optical transmitter configured in a small package. The tunable optical transmitter includes a housing with a volume formed by exterior walls. An electrical input interface is positioned at the first end of the housing and configured to receive an information-containing electrical signal. An optical output interface is positioned at the second end of the housing and configured to transmit an optical communication beam. A tunable semiconductor laser is positioned in the interior space and operable to emit a laser beam having a selectable wavelength. A semiconductor-based modulator is positioned in the interior space along an optical path of the laser beam and operatively coupled to the optical output interface. The semiconductor-based modulator is configured to impart modulation to the laser beam corresponding to an information-containing electrical signal received through the electrical input interface.02-10-2011
20110033193MODULATION METHOD, MODULATION PROGRAM, RECORDING MEDIUM, MODULATION DEVICE, AND OPTICAL TRANSMITTER - A modulation method according to the invention is applied to a modulation device in which a light source is driven by a differential signal while a modulation circuit and the light source are capacitively coupled. In the modulation method of the invention, when an average potential fluctuates at an input terminal of the light source, a potential fluctuation is externally provided using a control circuit such that a normal phase side and a reverse phase side become equal to each other in a time constant of the fluctuation in average potential, and transient states of the average potentials at the normal phase side and reverse phase side are equalized and cancel each other as in-phase components of a signal input to the light source, which allows an optical signal to be normally transmitted from the light source. The optical signal can normally be transmitted from the light source even before the average potentials at a normal phase input terminal and a reverse phase input terminal of the light source are stabilized.02-10-2011
20090214223CMOS-COMPATIBLE TUNABLE MICROWAVE PHOTONIC BAND-STOP FILTER - According to one embodiment, a microwave photonic band-stop (MPBS) filter uses an electrical input signal to drive an optical Mach-Zehnder modulator. A modulated optical carrier produced by the modulator is applied to an optical filter having at least two tunable spectral attenuation bands that are located substantially symmetrically on either side of the carrier frequency. The resulting filtered optical signal is applied to an optical-to-electrical (O/E) converter to produce an electrical output signal.08-27-2009
20110044700OPTICAL COMMUNICATIONS SYSTEM - The present invention relates to an optical communications system that allows improving OSNR while suppressing the power increase of pumping light for distributed Raman amplification. In the optical communications system, an optical fiber is laid in a transmission section between a transmitter station (or repeater station) and a receiver station (or repeater station), and optical signals are transmitted from the transmitter station to the receiver station via the optical fiber. In the optical communications system, pumping light for Raman amplification, outputted by a pumping light source provided in the receiver station, is fed into the optical fiber via an optical coupler, and the optical signals are distributed-Raman-amplified in the optical fiber. The transmission loss and the effective area of the optical fiber satisfy, at the wavelength of 1550 nm, a predetermined relationship.02-24-2011
20110116808REFLECTIVE OPTICAL TRANSMITTER - A semiconductor optical amplifier (SOA) is used in a double pass configuration with one of the output ports followed by an attenuator, which is followed by a modulator with a reflective facet. The variable loss between the SOA and the modulator is optimised, so that the SOA can be operated in a highly saturated regime without distorting the modulated signal. The SOA is firstly saturated by the input carrier, (05-19-2011
20100003035LASER DIODE HAVING AN ABRUPT TURN-ON, OPTICAL TRANSMITTER DEVICE USING THE SAME LASER DIODE AND OPTICAL COMMUNICATION APPARATUS - Provided are a laser diode which has low power consumption and can realize a high on/off extinction ratio by small variation of current and which can modulate optical signals at high speed, an optical transmitter, and an optical communication apparatus including the optical transmitter. The laser diode having an abrupt turn-on characteristic, comprises: an active region in which light is generated by application of current and gain is controlled; and an absorption region absorbing light generated in the laser diode at a current lower than an abrupt threshold current that is the same as or lower than an operation current, the operation current being a current level that allows the laser diode to generate a target optical power, wherein the output optical power rapidly increases at the abrupt threshold current.01-07-2010
20090324252Optical Transmitter - An optical transmitter includes a light source that outputs light superposed with a pilot signal having a predetermined frequency; an optical modulating unit that modulates the light from the light source according to an input electric signal; a detecting unit that detects a high-output-side maximum value of signal light output from the optical modulating unit, a fluctuation width of the high-output-side maximum value, and a fluctuation width of a low-output-side minimum value; a bias-potential adjusting unit that adjusts a bias potential of an electric signal to be input to the optical modulating unit based on the detected maximum value; and an amplitude adjusting unit that adjusts an amplitude of the electric signal to be input to the optical modulating unit based on the fluctuation width of the high-output-side maximum value and the fluctuation width of the low-output-side minimum value.12-31-2009
20090324251Tunable Radio Frequency and Microwave Photonic Filters - RF and microwave devices and techniques are disclosed for processing RF and microwave signals by using (1) photonic or optical components and (2) RF and microwave components. In some implementations, a part of the processing is performed in the RF and microwave domain such as applying a microwave or RF input signal to control an optical modulator, and another part of the processing is performed in the optical domain such as optical filtering of the modulated optical beam to select desired microwave or RF spectral components. The frequency of a selected spectral component can be tuned by either tuning the frequency of the optical beam that is modulated by the optical modulator or a filter that is used to filter modulated optical beam.12-31-2009
20090310976Illuminative light communication system - An light source control unit controls the flashing of a light source and the light amount of a light source according to information to be transmitted. Thus, light, which is modulated according to the information to be transmitted, is emitted from the light source. The light emitted from the light source is made to enter an optical fiber to pass therethrough and enter a light-scattering body which scatters and radiates the modulated light incident from the optical fiber. The scattered light serves as illumination light as it is. Furthermore, if the illumination light is decoded by a decoding unit after being received by a photoreceptor unit of a receiving set, then information carried by the illumination light can be received.12-17-2009
20110255875DUAL RATE QPSK/TCM-QPSK OPTICAL MODULATION - The present disclosure allows for optical link capacity to be optimized based on transmission parameters, such as amplifier gain, link loss, optical signal-to-noise ratio. For example, optical signals at wavelengths that are susceptible to impairments, such as non-linear effects, or that are not adequately amplified by an optical amplifier, may be modulated in accordance with lower rate/less spectrally efficient modulation formats (“low rate formats”) that are more noise tolerant. On the other hand, those optical signals at wavelengths that are less susceptible to or do not incur such impairments may be modulated in accordance with highly spectrally efficient /higher rate modulation formats (“high rate formats”) that are more noise sensitive. Accordingly, a maximum or optimized capacity may be realized through appropriately choosing, for each channel, a particular modulation format and channel spacing. Such optimized capacity can be readily obtained with adaptive driver circuits.10-20-2011
20100209119APPARATUS FOR CONTROLLING LIGHTING EQUIPMENT FOR LIGHTING COMMUNICATION - Disclosed is an apparatus for controlling an illumination device for optical communication, including an optical array having a plurality of light emitting elements, a visible ray communication unit for outputting an electrical signal for visible ray communication, an optical array driving unit for providing a control signal for individually controlling ON/OFF of the plurality of light emitting elements, and a logic operation unit for performing logic operations on signals provided from the visible ray communication unit and the optical array driving unit, and outputting resultant operated signals to the optical array.08-19-2010
20100260505SYSTEM AND METHOD FOR GENERATING MULTILEVEL CODED OPTICAL SIGNALS - A simple and effective all-optical system, producing a multilevel coded optical signal based on the M-ASK technology and by the minimized equipment. The novel all-optical modulation technique for optical M-ASK generation is based on nonlinear interaction between optical signals, say between N 2-ASK modulated pump signals having extinction ratio ER10-14-2010
20100021181Device, System, and Method of Communication Using Path State Modulation - A communication method including: modulating one more information data bits at a first site by selectively switching the path state of a first stream of photons, and demodulating said information data bits at a second site by detecting appearance and disappearance of an interference pattern of a second stream of photons correlated with said first stream of photons.01-28-2010
20100021180COMPLEMENTARY OPTICAL WIRING APPARATUS - A complementary optical wiring apparatus includes an optical transmitter, first and second optical transmission lines, and an optical receiver, the optical transmitter has a first operation mode of transmitting an optical signal synchronized with the rising of one electrical input signal via the first optical transmission line and transmitting an optical signal synchronized with the falling thereof via the second optical transmission line, and a second operation mode of transmitting an optical signal synchronized with the rising and falling of one of two electrical input signals via the first optical transmission line and transmitting an optical signal synchronized with the rising and falling of the other electrical input signal via the second optical transmission line, and is operated after one of the two operation modes is selected.01-28-2010
20100021179OPTICAL FIELD RECEIVER AND OPTICAL TRANSMISSION SYSTEM - An optical field receiver comprises an optical brancher that branches a received optical multilevel signal into first and second optical signals; an optical delayed detector that performs delayed detection on the first optical signal by a delayed detector with a delay time of T/2 (where T is equal to a symbol time) and a phase difference of 90 degrees; a balanced optical receiver that converts the optical signal outputted from the first delay detector to an electric signal; and an optical intensity receiver that converts the second optical signal to an electric signal; and an electric field calculating part that generates, from the output signals of the first and second optical receivers, first and second reproduced signals indicative of the phase angle and amplitude value of the received symbol represented by the complex signal in each symbol time T.01-28-2010
20090003840Controlling a bias voltage for a Mach-Zehnder modulator - In one embodiment, the present invention includes a controller coupled to an optical modulator to receive a dither signal, determine a difference between the dither signal and a previous dither signal, determine a derivative of the difference with respect to a bias voltage difference between first and second bias voltages, and control a bias voltage for the optical modulator based on the derivative. Other embodiments are described and claimed.01-01-2009
20120002978OPTICAL SINGLE-SIDEBAND TRANSMITTER - A method for generating an optical single sideband signal comprising the steps of splitting an optical field into two parts and introducing a relative phase delay of +/−π/4 radians in each direction of transmission to one of the parts, intensity reflection-modulating each part with electrical signals having a relative phase delay of +/−π/2 radians and then recombining the reflection-modulated signals.01-05-2012
20120008963OPTICAL MODULATOR, OPTICAL TRANSMISSION DEVICE, AND BIAS ADJUSTING METHOD - Included are a first modulator, a second modulator, a first optical amplifier that amplifies an output of the first modulator at an amplification factor based on a first bias signal, a second optical amplifier that amplifies an output of the second modulator at an amplification factor based on a second bias signal, an optical phase adjuster that phase-rotates an output of the second optical amplifier, an optical multiplexer that multiplexes an output of the first optical amplifier with an output of the optical phase adjuster, and a second bias corrector that generates a first pulse signal and a second pulse signal, which are complementary to each other, and obtains a first bias value and a second bias value based on a change of strength of an output signal of the optical multiplexer. The first and second pulse signals are superimposed on the first and second bias signals, respectively.01-12-2012
20110097091TIME DELAY ADJUSTMENT DEVICE AND METHOD - A time delay adjustment method is provided, which includes the following steps. A same scrambling signal is added into two received signals. The added scrambling signals are then extracted. A delay difference between the two signals is detected according to a difference between the two extracted scrambling signals. The delay difference between the two signals is adjusted by delaying one or both of the two signals. Furthermore, a time delay adjustment device and an optical transmission apparatus are also provided. Therefore, time delay can be adjusted online, and real-time monitoring and adjustment of delay difference is also achieved.04-28-2011
20120106979OPTICAL TRANSMITTER AND OPTICAL TRANSMISSION APPARATUS - An optical transmitter is disclosed. An optical modulator outputs an optical signal by modulating light being input, and has an optical absorption characteristic which changes a degree of optical absorption depending on a bias voltage being applied and includes a first characteristic region and a second characteristic region in which the degree of the optical absorption is greater than the first characteristic region. An power source applies an electric field generated by applying a predetermined shutdown bias voltage corresponding to the second characteristic region to electrodes provided in two interference optical guides formed in the optical modulator, when an output of the optical signal from the optical modulator is shut down to be less than or equal to a desired amount.05-03-2012
20100172654LIGHT EMITTING ELEMENT CIRCUIT, LIGHT TRANSMITTING SYSTEM, LIGHT TRANSMITTING MODULE, AND ELECTRONIC DEVICE - A light emitting element circuit has a light emitting element, a drive circuit that supplies a current to the light emitting element, and a signal circuit that autonomously supplies a signal according to an ambient temperature. The signal adjusts the current such that the current corresponds to a temperature characteristic of the light emitting element.07-08-2010
20100092183FREQUENCY TUNABLE TERAHERTZ CONTINUOUS WAVE GENERATOR - A frequency tunable terahertz continuous wave generator controls the number of feedbacks of an optical signal output from an optical intensity modulator by adding a feedback loop between input and output terminals of the optical intensity modulator, thereby simply tuning a frequency of a terahertz continuous wave.04-15-2010
20120189321Dual Drive Externally Modulated Laser - A method of generating a signal in an optical transmitter comprising a directly modulated laser and an amplitude modulator for modulating the output of the laser. The method comprises the steps of applying a first modulation signal representing data to be transmitted to the current of the laser such that the output frequency of the laser is modulated, and applying a second modulation signal representing the data to be transmitted to the amplitude modulator such that the amplitude of the laser output is modulated.07-26-2012
20120082467OPTICAL TRANSMITTER, OPTICAL TRANSMISSION DEVICE, AND METHOD OF CONTROLLING OPTICAL TRANSMITTER - An optical transmitter includes a driver outputting data; an optical modulator outputting an optical modulation signal by modulating light from a light source based on the data output from the driver; a detector detecting at least one of a signal intensity of the optical modulation signal from the optical modulator and a signal intensity of the data from the driver and outputs a detection result; and an adjustor adjusting a signal parameter of the data based on the detection result.04-05-2012
20120082466UPSAMPLING OPTICAL TRANSMITTER - Consistent with the present disclosure, data, in digital form, is received by a transmit nodes of an optical communication, and converted to analog signal by a digital-to-analog converter (DAC) to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data. The modulated light is then transmitted over an optical communication path to a receive node. At the receive node, the modulated optical signal, as well as other modulated optical signals are supplied to a photodetector circuit, which receives additional light at one of the optical signal wavelengths from a local oscillator laser. An analog-to-digital converter (ADC) is provided in the receive node to convert the electrical signals output from the photodetector into digital form. The output from the ADC is then filtered in the electrical domain, such that optical demultiplexing of individual channels is unnecessary.04-05-2012
20120269522DIFFERENTIAL TRANSMISSION CIRCUIT AND INFORMATION PROCESSING SYSTEM - A differential transmission circuit includes a grounded conductive layer, a pair of transmission line conductors, a conductive film and a via hole which connects the grounded conductive layer to the conductive film. The differential transmission circuit further includes a straight-line region which is present in the differential transmission circuit through which a differential transmission signal output by a driving circuit is transmitted and in which the pair of transmission line conductors extends parallel so as to have a first width, and a band rejection filter region in which the pair of transmission line conductors planarly overlaps the conductive film and extends parallel so as to have a second width narrower than the first width and a common mode of the differential transmission signal is attenuated at one of the frequencies which are natural number multiples of a frequency corresponding to the predetermined bit rate.10-25-2012
20100232806OPTICAL TRANSMITTER DEVICE AND OPTICAL TRANSMITTER MODULE - Provided are an optical transmitter device and an optical transmitter module which are capable of reducing the optical transmitter module size while maintaining a state where an excellent optical transmission waveform quality is obtained over a wide range of frequencies. The optical transmission module (09-16-2010
20120087677METHOD AND APPARATUS FOR TRANSMITTING DATA USING VISIBLE LIGHT COMMUNICATION - A transmitting apparatus using visible light communication generates a light source control signal from color information representing additional information and transmits additional information with a color of light that is emitted by a light source by controlling an on/off time of a plurality of LEDs according to the light source control signal. Therefore, a user can intuitively know additional information from a color of light that is emitted by the light source.04-12-2012
20100202784OPTICAL MODULATOR - In an optical modulator, lights that have been branched by an input optical branching section are input via curved waveguides to a plurality of optical modulation sections arranged in parallel on the same substrate. In the optical modulation sections, optical branching sections of an MZ type optical waveguide are arranged shifted to an output side in the longitudinal direction (x direction) of the substrate, corresponding to an arrangement of input ends of signal electrodes. As a result, even if the input ends of the signal electrodes of the respective optical modulation sections are arranged side by side with a predetermined spacing on one side face of the substrate, input light can be applied to the respective optical modulation sections at low loss, without incurring an increase in the drive voltage.08-12-2010
20130170841METHOD AND APPARATUS FOR TRANSMITTING HIGH-LEVEL QAM OPTICAL SIGNALS WITH BINARY DRIVE SIGNALS - Methods and apparatus for power-efficiently and reliably transmitting high-level quadrature amplitude modulation (QAM) optical signals using binary drive signals. Even though binary signals are used to drive a QAM modulator directly, without digital-to-analog conversion, the methods and apparatus disclosed allow the transmission of pilot symbol sequences having near optimal properties, such as a constant power profile in the time domain; a mean power that is approximately the same as the mean power of the data symbols; and roughly uniform amplitude in the frequency domain for non-zero frequency components of the pilot symbol sequence. The binary drive signals can be processed so that the modulated optical signals are selectively constrained to a subset of points of the QAM constellation to form a QAM constellation with reduced size and a mean power that is approximately the same as the mean power of the original QAM constellation.07-04-2013
20130129361OPTICAL TRANSMITTER MODULE AND TRANSMITTING METHOD - An optical transmitter module includes at least one light source, at least one optical modulator aligned to the at least one light source one by one, a first light interleaver, and at least one optical fiber. Each light source emits a light wave with a particular wavelength. Each optical modulator modulates the light wave of the corresponding light source, to form a central light wave having the particular wavelength and a number of secondary light waves having secondary wavelengths. The first light interleaver separates the secondary light waves from the central light wave. The at least one optical fiber transmits the secondary light waves.05-23-2013
20080199188Interferometric communication - Embodiments of interferometric communication are disclosed.08-21-2008
20110236033Optical Field Transmitter and Optical Transmission System - It is provided an optical field transmitter comprising a light source, one or more DA converters, an optical field modulator, a complex information multilevel signal generator circuit, and a phase pre-integration circuit. The optical field modulator modulates light output from the light source into a optical field signal by using the analog signal converted from a complex multilevel information signal including phase pre-integration complex information by the one or more DA converters. A phase angle of the complex multilevel information signal at a complex signal point is any one of values of integral multiples obtained by dividing 360 degrees by a positive integer N. An amplitude value of the complex multilevel information signal at the complex signal point is any one of values of a positive integer M. A total number of the complex signal points which may be taken is lower than a product of N and M.09-29-2011

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