| Patent application number | Description | Published |
|---|
| 20080199189 | COLORLESS OPTICAL DEMODULATOR FOR DIFFERENTIAL QUADRATURE PHASE SHIFT KEYING DWDM SYSTEMS - A colorless optical DQPSK demodulator and system operating over multiple, equally-spaced DWDM channels with fixed optical delays—capable of demodulating DQPSK within signals within DWDM communications wave bands on ITU grids using delay interferometers having fixed free spectral range at 20 GHz or 25 GHz. | 08-21-2008 |
| 20080253768 | High Bit Rate Packet Generation with High Spectral Efficiency in an Optical Network - Optical packets are generated by generating a first optical beam with a first wavelength and a second optical beam with a second optical beam. The first optical beam is modulated with a payload signal and then filtered to reduce the bandwidth of the signal. The second optical beam is modulated with a label signal. The filtered modulated first optical beam and modulated second optical beam are combined to generate a dual-wavelength optical beam. | 10-16-2008 |
| 20080279556 | Wavelength Division Multiplexed Passive Optical Network - Data is transmitted between a central office and customer premises by a wavelength division multiplex passive optical network. Two laser beams with separate wavelengths are transmitted from the central office to an optical network unit in the customer premises. Both laser beams carry downstream data. One laser beam is intensity modulated by on/off keying. The other laser beam is phase modulated by differential phase shift keying, which maintains a constant optical intensity. The first laser beam is received by a first optical receiver, which demodulates the first downstream data. The second laser beam is split in two. One laser beam is sent to a second optical receiver, which demodulates the second downstream data. The other laser beam is sent to a reflective semiconductor amplifier, which modulates the beam with upstream data and transmits the beam back to a receiver in the central optical system. | 11-13-2008 |
| 20090059351 | DEMODULATOR SYSTEM AND METHOD USING MULTILEVEL DIFFERENTIAL PHASE SHIFT KEYING - A demodulator and demodulation method includes an optical coupler configured to receive an input signal. The optical coupler couples the signal to an even number of branches. Each branch including at least one interferometer configured to split, combine and interfere with an optical signal from one of within the branch or from another branch. A common optical delay is disposed on one of every two branches between the optical coupler and the interferometer of the branch. | 03-05-2009 |
| 20090067839 | STORAGE AREA NETWORK EXTENSION OVER PASSIVE OPTICAL NETWORKS USING PARALLEL SIGNAL DETECTION - A storage area network extension, network and method include a storage terminal coupled to a remote node. The remote node is connected to a passive optical network (PON) for transferring data signals in the PON and storage signals to/from the storage terminal by employing subcarrier channels in the PON to enable concurrent bidirectional transfer of the data and the storage signals. A storage area network is coupled to the storage terminal and configured to store and retrieve the storage signals for transfer over the PON. | 03-12-2009 |
| 20090214210 | 100 Gbit/s OFDM Optical Signal Generation - A method includes modulating lightwaves to provide first and second OFDM signal sidebands at a first polarization direction and first and second OFDM signal sidebands at a second polarization direction, and combining sidebands that are oppositely positioned and joined from the first and second OFDM signal sidebands at each polarization direction to provide a polarization multiplexing OFDM signal. | 08-27-2009 |
| 20090274462 | CENTRALIZED LIGHTWAVE WDM-PON EMPLOYING INTENSITY MODULATED DOWSTREAM AND UPSTREAM - An optical system and method includes a source-free optical network unit coupled to an optical fiber for receiving a centralized lightwave carrier signal with downstream data over the optical fiber. The optical network unit includes a coupler configured to split the original carrier signal into a first path and a second path. The first path includes an optical filter configured to reduce fading effects of the carrier signal. The second path includes a modulator configured to remodulate the centralized lightwave carrier signal with upstream data to produce an upstream data signal for upstream transmission. | 11-05-2009 |
| 20090279891 | ALL-OPTICAL WAVELENGTH CONVERSION FOR A POLARIZATION MULTIPLEXING OPTICAL SIGNAL - An apparatus includes a first laser source for providing a first lightwave; a first optical coupler that is polarization maintaining for dividing the first lightwave into first and second optical carrier lightwaves; first and second modulators for modulating respective ones of the first and second carrier lightwaves with information; a polarization beam combiner for combining the modulated first and second carrier lightwaves which generates a polarization multiplexing optical signal; second and third lasers for providing second and third lightwaves whose wavelengths are one of both longer than that of the first lightwave and shorter than that of the first lightwave, a second optical coupler that is polarization maintaining for combining the second and third lightwaves; and a third optical coupler for combining the modulated first and second carrier lightwaves from the polarization beam combiner and the combined second and third lightwaves out of the second optical coupler for transmission over an optical medium. | 11-12-2009 |
| 20090285577 | Optical Frontend for Integration of Optical and Wireless Networks - Data is transmitted by radio over fiber in a wavelength division multiplex optical transmission system. Data is transmitted over a single optical channel by directly modulating a single wavelength laser with a baseband data signal. Multiple single wavelength laser beams are multiplexed into a single multi-wavelength laser beam. All of the single optical channels are up-converted to RF frequencies by modulating the intensity of the multi-wavelength laser beam with an RF carrier. | 11-19-2009 |
| 20090290877 | Monitoring for High Speed OFDM Signal Transmission - A method includes coupling an optical signal upconverted to a higher frequency and a digital signal having a bit rate similar to that of a subchannel of the upconverted optical signal, and obtaining, responsive to the coupling, a transmission signal with an optical carrier frequency carrying the digital signal and subchannels about the optical carrier frequency carrying the upconverted optical signal, the bit rate of the optical carrier being similar to that of the subchannels. In a preferred embodiment, the coupling includes electrically power coupling the upconverted optical signal with the digital signal, and modulating the coupled optical carrier frequency carrying the digital signal and subchannels about the optical carrier frequency carrying the upconverted optical signal. | 11-26-2009 |
| 20090290878 | Generating an Optical OFDM Signal with Reduced OSNR Requirement - A method for generating an optical OFDM signal with reduced optical signal to nose ratio requirement includes separating an up-converted OFDM signal into a first part and a second part out of phase with the first part; driving a modulator with the first and second parts of the of the up-converted OFDM signal; and varying a lightwave with the modulator for generating a carrier suppressed OFDM signal having improved receiver sensitivity. | 11-26-2009 |
| 20100028001 | Generation Of At Least 100 Gbit/s Optical Transmission - A method includes generating at least two lightwave carriers from a lightwave source, the carriers having a wavelength spacing, creating an up-subchannel and a down-subchannel orthogonal to one another and spaced apart based on the fixed wavelength spacing from modulations of the lightwave carriers according to respective up-converted OFDM signals that are carrier suppressed, and combining one lightwave from the up-subchannel and one lightwave from the down-subchannel into an optical channel for transmission over an optical fiber. | 02-04-2010 |
| 20100046962 | All Optical Up-Conversion System - An optical system for providing all-optical up-conversion of a baseband signal including an all-optical up-converter responsive to baseband signals to provide corresponding dual sideband signals about a suppressed optical carrier, said dual sideband signals each having the same polarization direction, being phase locked, having the same optical power and having a fixed frequency spacing; and an optical filter for filtering the carrier signals and providing wavelength division multiplexed signals without optical carriers. In a preferred embodiment, the all-optical up-converter includes an intensity modulator for generating two pump lightwaves that are carrier suppressed in response to the intensity modulator receiving a laser light source and being driven by an RF signal, wherein the intensity modulator is DC biased at a null point, an optical combiner for combining the baseband signal and the two pump lightwaves, a nonlinear medium for four wave mixing the baseband signal and two pump lightwaves to generate the baseband signal and corresponding dual sideband signals, and an optical interleaver for removing the baseband signal and two pump lightwaves to provide said sideband signals about the suppressed optical carrier. | 02-25-2010 |
| 20100086303 | HIGH SPEED POLMUX-OFDM USING DUAL-POLMUX CARRIERS AND DIRECT DETECTION - A polarization multiplexing, orthogonal frequency division multiplexing (POMUX) transmission system utilizing direct detection. | 04-08-2010 |
| 20100086314 | Method and Apparatus for an Optical Duty Cycle for an Optical Digital Coherent System - An optical apparatus includes a quadrature phase shift keying modulator for generating a non-return-to-zero quadrature phase shift keyed NRZ-QPSK signal from a received lightwave, the modulator being driven by a radio frequency RF signal, an intensity modulator for carving the NRZ-QPSK signal to return-to-zero RZ pulses with a different duty cycle than that of the NRZ-QPSK, the intensity modulator being driven by a radio frequency RF clock signal to change the NRZ-QPSK to an RZ-QPSK signal, and an optical filter with a narrow band for filtering the signal from the intensity modulator to increase optical power that is useable by an optical digital coherent detection system. | 04-08-2010 |
| 20100208853 | FEEDBACK ADJUSTABLE CONSTELLATION DE-MAPPER - A system and method to adjust the symbol constellation used to de-map a signal in an optical coherent communications system. A feedback de-mapper adjustment module is configured to compare average Error Vector Magnitude and Bit Error Ratio to a pre-defined table to determine when a constellation de-mapper mismatch occurs. The feedback de-mapper adjustment module then rotates the de-mapper constellation in order to compensate for phase drift. | 08-19-2010 |
| 20100247104 | Optical Communication System and Method for Generating Dark Return-to-Zero and DWDM Optical MM-Wave Generation For ROF Downstream link using Optical Phase Modulator and Optical Interleaver - A method of generating a dark-RZ pulse in an optical communications system with a dual-arm modulator by setting a direct current bias on the modulator to a specific value such that an output optical power from the modulator achieves a maximum value when the RF signals on the first and second arms of the modulator are off and maintaining the direct current bias at the specific value and applying RF signals to the first and second arms of the modulator and delaying one of the RF signals applied to one of the first and second arms relative to the other of the RF signals such that a dark-RZ pulse is generated with a duty cycle based on the delay. Another aspect of the invention provides a method for generating dense wave division multiplexing (DWDM) optical mm-waves in an optical transmission system by phase modulated DWDM optical signal and applying the phase modulated DWDM optical signal to an input port of an optical interleaver, the optical interleaver having a specified bandwidth to suppress the optical carriers and convert the DWDM optical signal to DWDM optical mm-waves; and amplifying the DWDM optical mm-waves and transmitting the DWDM optical mm-waves over single mode fiber (SMF). | 09-30-2010 |
| 20100329696 | 16 Quadrature Amplitude Modulation Optical Signal Transmitter - An optical transmitter including a dividing optical coupler for dividing a lightwave onto optical paths; a first optical modulator in a first of the optical paths and driven by an I component of a first signal and a I component of a second signal for modulating the lightwave, a DC bias of the first optical modulator being at a quadrature point; a second optical modulator in a second of the optical paths and driven by a Q component of the first signal and a Q component of the second signal for modulating the lightwave, a DC bias of the second optical modulator being at the quadrature point; a phase shifter for generating a 90 degree phase shift in the Q components of the first and second signals that are modulated by the second optical coupler; and a combining optical coupler for combining the modulated lightwave from the first optical coupler and the phase shifted Q components of the first and second signals for generating a quadrature amplitude modulated signal. | 12-30-2010 |
| 20110020003 | Generating A 400-Gbit/s Single-Channel Optical Signal - A method for generating a 400 Gb/s single channel optical signal from multiple modulated subchannels includes carving respective modulated subchannels into return-to-zero RZ modulated subchannels having non-overlapping peaks with intensity modulators having a duty cycle less than 50%, and combining the subchannels into a single channel signal aggregating the bit rate of each of the subchannels. The subchannels are combined with a flat top optical component for increased subsequent receiver sensitivity. | 01-27-2011 |
| 20110069964 | Optical Signal Sideband Millimeter-Wave Signal Generation for Super-Broadband Optical Wireless Network - An optical wireless network includes an optical coupler for diverting received millimeter-wave signals comprised of an optical carrier and second order sidebands into multiple transmission paths; a downstream optical path being one of the multiple transmission paths and including an optical filter for filtering passing through the optical carrier with a single sideband, a converter for converting the optical carrier and single sideband to a corresponding electrical signal for amplification and broadcast transmission from an antenna; and an upstream path being one of the multiple transmission paths and having a filter for passing through the optical carrier only from the mm-wave signals and an intensity modulator driven by data received over the antenna to modulate the optical carrier for optical transmission to a receiving destination. | 03-24-2011 |
| 20110081151 | Generation and Coherent Detection of High-Speed Orthogonal DWDM Optical Signal - A high speed orthogonal dense wavelength division multiplexing DWDM signal generator includes a multi-peak continuous wave signal generator responsive to a light source, an optical filter for separating multi-peaks of lightwaves from the generator; and a polarization multiplexing stage responsive to the multi-peaks of lightwaves from the optical filter for providing a polarization multiplexing optical signal. The generator includes a cascaded phase modulator and intensity modulator driven by a repetitive frequency (I) to generate multiple spectral peaks, each peak being modulated by an optical modulator driven by a respective baud rate (f baud/s) electrical signal. | 04-07-2011 |
| 20110085797 | ULTRA WIDE-RANGE FREQUENCY OFFSET ESTIMATION FOR DIGITAL COHERENT OPTICAL RECEIVERS - Methods and systems for receiving an optical signal using cascaded frequency offset estimation. Coherently detecting an optical signal includes compensating for a coarse laser frequency offset between a transmitting laser and a local oscillator laser by determining a maximum phase error (MPE) in the optical signal, compensating for a residual laser frequency offset between the transmitting laser and the local oscillator laser, and decoding data stored in the optical signal. | 04-14-2011 |
