Abstract: An optically-switch data network includes an optical data bus, an optical wavelength bus, and multiple nodes connected by the optical data bus and the optical wavelength bus. A first node determines that it has communication information to transmit to a second node, and determines if a first subscription signal is present on the optical wavelength bus. The first subscription signal includes a target frequency. If the first subscription signal is not present on the optical wavelength bus, the first node injects an optical communication signal onto the optical data bus. The optical communication signal includes the communication information and a carrier wave. The carrier wave includes the target frequency. The second node receives the optical communication signal using the optical data bus. If the first subscription signal is present on the optical wavelength bus, injection of the optical communication signal onto the optical data bus is postponed.

Abstract: In a system, known digitizer signals (known analog signals or digital representations of known analog signals) are generated. The known digitizer signals are input into digitizers (analog-to-digital converter (ADCs) or digital-to-analog converter (DACs)) to output generated digitizer signals (generated digital representations or generated analog signals). The generated digitizer signals are analyzed in relation to the known digitizer signals to generate coupling coefficients, which can be either scalar quantities or finite-impulse-response (FIR) filter functions. Subsequent digitizer signals are generated. The subsequent digitizer signals are modified using the coupling coefficients to generate modified digitizer signals according to formulae. The modified digitizer signals are used directly as digital representations, or are input to the DACs to output modified analog signals that substantially match subsequent analog signals.

Abstract: A system includes a first optical frequency comb generator that generates a first parametrically generated comb using parametric mixing comprising a first plurality of optical waves including at least one first optical wave. The system includes a second optical frequency comb generator that generates a second parametrically generated comb using parametric mixing comprising a second plurality of optical waves. The second optical frequency comb generator receives the at least one first optical wave and generates the second plurality of optical waves using the at least one first optical wave. Respective center frequencies of one or more optical waves of the first plurality of optical waves are aligned in frequency with respective center frequencies of one or more optical waves of the second plurality of optical waves.

Abstract: In a system, known digital representations are generated, and test analog signals are generated using the known digital representations. The test analog signals are transmitted using a transmitter of a transmission system. The test analog signals are received using a receiver of the transmission system and used to generate test received digital representations. The test received digital representations are cross-correlated with the known digital representations to generate a mixing matrix. The mixing matrix is inverted to generate a de-mixing matrix, which is applied to subsequent digital data to be encoded onto a signal and transmitted by the transmitter to generate pre-compensated digital data.

Abstract: In some embodiments, an integrated photonic module contains, a silicon-on-insulator platform, an integrated photonic component, and an optical fiber. The silicon-on-insulator platform can contain a silicon-on-insulator photonic circuit, a co-fabricated spot size converter, and a co-fabricated micromachined trench structure. The co-fabricated micromachined trench structure can contain dimensions compatible with the optical fiber, and the optical fiber can be bonded to, and disposed at least partially within, the micromachined trench structure. The optical modes of the optical fiber, the integrated photonic component, the co-fabricated spot size converter, and the silicon-on-insulator photonic circuit can also be spatially aligned with one another.

Abstract: Phase noise is corrected in a communication system including a modulated signal having a constellation including multiple constellation points. The system and methods include a coarse phase recovery followed by a fine phase recovery. Coarse phase corrected points can be generated using an Mth power operation. Fine phase corrected points can be generated by rotating each coarse phase corrected point by an angle that is determined by the location of that coarse phase corrected point in the constellation, and applying a phase offset function to each transformed point. A phase noise mitigated constellation can be generated by derotating the fine phase corrected points.

Abstract: In an improved wavelength-division multiplexed system, transmitters modulate carrier signals that are phase or frequency correlated with each other. Receivers retrieve transmission data from the modulated carrier signals by demodulating and equalizing the modulated carrier signals using oscillating signals that are also phase or frequency correlated with each other. Each oscillating signal has a wavelength that matches a wavelength of a corresponding one of the carrier signals. At least one of the receivers generates process information during the demodulating and equalizing. The process information is sent to at least one other receiver, which uses the process information to retrieve at least a portion of the transmission data.

Abstract: In a transmission system, a transmission signal is generated from transmission data. The transmission signal has a series of shaped pulses, such as raised-cosine or root-raised-cosine shaped pulses, formed using a pulse-shaping filter. A reception signal, based on the transmission signal having passed through a transmission channel, is sampled to generate sampled digital data. The sampled digital data is filtered through a receiver filter to regenerate the transmission data, where the pulse shaping filter and the receiver filter are mismatched.

Abstract: In a system, known digitizer signals (known analog signals or digital representations of known analog signals) are generated. The known digitizer signals are input into digitizers (analog-to-digital converter (ADCs) or digital-to-analog converter (DACs)) to output generated digitizer signals (generated digital representations or generated analog signals). The generated digitizer signals are analyzed in relation to the known digitizer signals to generate coupling coefficients, which can be either scalar quantities or finite-impulse-response (FIR) filter functions. Subsequent digitizer signals are generated. The subsequent digitizer signals are modified using the coupling coefficients to generate modified digitizer signals according to formulae. The modified digitizer signals are used directly as digital representations, or are input to the DACs to output modified analog signals that substantially match subsequent analog signals.

Abstract: Timing recovery systems and methods can include receiving a signal with Nyquist shaped pulses, sampling the signal using an analog-to-digital converter at a sampling rate, generating a plurality of delayed sampled signals from the received pulses, resampling each delayed sampled signal to 1 sample per symbol, taking the absolute value of each resampled signal, raising the absolute value of each resampled signal to the fourth power, taking the mean of the fourth power of the absolute value of each resampled signal, feeding all of the mean values into a phase estimator, and using the output from the phase estimator for timing correction. The output from the phase estimator can either be fed back to the analog-to-digital converter, or to an interpolation stage that adjusts sampling instants of the sampled signals output from the analog-to-digital converter, to correct the timing.

Abstract: A system includes a first optical frequency comb generator that generates a first parametrically generated comb using parametric mixing comprising a first plurality of optical waves including at least one first optical wave. The system includes a second optical frequency comb generator that generates a second parametrically generated comb using parametric mixing comprising a second plurality of optical waves. The second optical frequency comb generator receives the at least one first optical wave and generates the second plurality of optical waves using the at least one first optical wave. Respective center frequencies of one or more optical waves of the first plurality of optical waves are aligned in frequency with respective center frequencies of one or more optical waves of the second plurality of optical waves.

Abstract: In a transmission system, a transmission signal is generated from transmission data. The transmission signal has a series of shaped pulses, such as raised-cosine or root-raised-cosine shaped pulses. A reception signal, based on the transmission signal having passed through a transmission channel, is sampled to generate sampled digital data. The sampled digital data is filtered through a super-Gaussian filter to regenerate the transmission data.

Abstract: In a system, known digitizer signals (known analog signals or digital representations of known analog signals) are generated. The known digitizer signals are input into digitizers (analog-to-digital converter (ADCs) or digital-to-analog converter (DACs)) to output generated digitizer signals (generated digital representations or generated analog signals). The generated digitizer signals are analyzed in relation to the known digitizer signals to generate coupling coefficients, which can be either scalar quantities or finite-impulse-response (FIR) filter functions. Subsequent digitizer signals are generated. The subsequent digitizer signals are modified using the coupling coefficients to generate modified digitizer signals according to formulae. The modified digitizer signals are used directly as digital representations, or are input to the DACs to output modified analog signals that substantially match subsequent analog signals.

Abstract: In a system, known digitizer signals (known analog signals or digital representations of known analog signals) are generated. The known digitizer signals are input into digitizers (analog-to-digital converter (ADCs) or digital-to-analog converter (DACs)) to output generated digitizer signals (generated digital representations or generated analog signals). The generated digitizer signals are analyzed in relation to the known digitizer signals to generate coupling coefficients, which can be either scalar quantities or finite-impulse-response (FIR) filter functions. Subsequent digitizer signals are generated. The subsequent digitizer signals are modified using the coupling coefficients to generate modified digitizer signals according to formulae. The modified digitizer signals are used directly as digital representations, or are input to the DACs to output modified analog signals that substantially match subsequent analog signals.

Abstract: In a system, known digital representations are generated, and test analog signals are generated using the known digital representations. The test analog signals are transmitted using a transmitter of a transmission system. The test analog signals are received using a receiver of the transmission system and used to generate test received digital representations. The test received digital representations are cross-correlated with the known digital representations to generate a mixing matrix. The mixing matrix is inverted to generate a de-mixing matrix, which is applied to subsequent digital data to be encoded onto a signal and transmitted by the transmitter to generate pre-compensated digital data.

Abstract: In an improved wavelength-division multiplexed system, transmitters modulate carrier signals that are phase or frequency correlated with each other. Receivers retrieve transmission data from the modulated carrier signals by demodulating and equalizing the modulated carrier signals using oscillating signals that are also phase or frequency correlated with each other. Each oscillating signal has a wavelength that matches a wavelength of a corresponding one of the carrier signals. At least one of the receivers generates process information during the demodulating and equalizing. The process information is sent to at least one other receiver, which uses the process information to retrieve at least a portion of the transmission data.

Abstract: In a transmission system, a transmission signal is generated from transmission data. The transmission signal has a series of shaped pulses, such as raised-cosine or root-raised-cosine shaped pulses. A reception signal, based on the transmission signal having passed through a transmission channel, is sampled to generate sampled digital data. The sampled digital data is filtered through a super-Gaussian filter to regenerate the transmission data.

Abstract: An optically-switch data network includes an optical data bus, an optical wavelength bus, and multiple nodes connected by the optical data bus and the optical wavelength bus. A first node determines that it has communication information to transmit to a second node, and determines if a first subscription signal is present on the optical wavelength bus. The first subscription signal includes a target frequency. If the first subscription signal is not present on the optical wavelength bus, the first node injects an optical communication signal onto the optical data bus. The optical communication signal includes the communication information and a carrier wave. The carrier wave includes the target frequency. The second node receives the optical communication signal using the optical data bus. If the first subscription signal is present on the optical wavelength bus, injection of the optical communication signal onto the optical data bus is postponed.

Abstract: An optically-switch data network includes an optical data bus, an optical wavelength bus, and multiple nodes connected by the optical data bus and the optical wavelength bus. A first node determines that it has communication information to transmit to a second node, and determines if a first subscription signal is present on the optical wavelength bus. The first subscription signal includes a target frequency. If the first subscription signal is not present on the optical wavelength bus, the first node injects an optical communication signal onto the optical data bus. The optical communication signal includes the communication information and a carrier wave. The carrier wave includes the target frequency. The second node receives the optical communication signal using the optical data bus. If the first subscription signal is present on the optical wavelength bus, injection of the optical communication signal onto the optical data bus is postponed.

Abstract: An optically-switch data network includes an optical data bus, an optical wavelength bus, and multiple nodes connected by the optical data bus and the optical wavelength bus. A first node determines that it has communication information to transmit to a second node, and determines if a first subscription signal is present on the optical wavelength bus. The first subscription signal includes a target frequency. If the first subscription signal is not present on the optical wavelength bus, the first node injects an optical communication signal onto the optical data bus. The optical communication signal includes the communication information and a carrier wave. The carrier wave includes the target frequency. The second node receives the optical communication signal using the optical data bus. If the first subscription signal is present on the optical wavelength bus, injection of the optical communication signal onto the optical data bus is postponed.