Abstract: A method for automatic power and modulation management in a communication network includes (a) generating a discontinuous management function that is a weighted function of at least spectral efficiency and power consumption of the communication network, (b) determining, from the discontinuous management function, an optimal modulation format, an optimal forward error correction (FEC) rate, and an optimal output power of a transmitter of the communication network, which collectively achieve a maximum value of the management function, and (c) causing the transmitter to operate according to the optimal modulation format, the optimal FEC rate, and the optimal output power.

Abstract: A fiber-optic network is used to interrogate a geographic area for propagating waves initiated by events external to the fiber-optic network. The probe signals are frequency modulation aligned and/or carrier frequency aligned with one another. Scattered energy indicative of probe signals' interactions with the propagating wave are time aligned with one another, amplitude normalized, cross correlated and/or added together to improve signal-to-noise and spatial resolution.

Abstract: A communications network includes a central communication unit, an optical transport medium, and a plurality of remote radio base stations. The central communication unit generates, within a selected millimeter-wave frequency band, a plurality of adjacent two-tone optical frequency conjugate pairs. Each conjugate pair includes a first optical tone carrying a modulated data signal, and a second optical tone carrying a reference local oscillator signal. The optical transport medium transports the plurality of two-tone conjugate pairs to the plurality of radio base stations, and each base station receives at least one conjugate pair at an optical front end thereof. The optical front end separates the first optical tone from the second optical tone, and converts the first optical tone into a millimeter-wave radio frequency electrical signal.

Abstract: An injection locking laser source is provided for an optical communications system. The injection locking laser source includes a laser cavity configured to receive an externally injected low linewidth primary light source. The laser cavity includes a cavity length, a cavity facet reflectivity, and a cavity quality factor. The injection locking laser source further includes an emitting region configured to output a secondary light source injection locked to the externally injected low linewidth primary light source at a stable detuning frequency based on a photon number, a steady-state phase, and a carrier number of the primary light source injected into the cavity.

Abstract: A method for extracting a plurality of data streams from a time-frequency division multiplexed (TFDM) signal includes determining a plurality of sub-channels of the TFDM signal, where each of the plurality of sub-channels has a respective one of a plurality of frequency ranges. The method also includes down-converting, based on the plurality of frequency ranges, the TFDM signal into a plurality of down-converted signals, where each down-converted signal corresponds to a respective one of the plurality of sub-channels. The method also includes extracting the plurality of data streams from a respective one of the plurality of down-converted signals.

Abstract: An integrated transceiver is provided for a coherent optical communication network. The integrated transceiver includes a first optical transceiver portion configured to receive and transmit coherent optical signals from and to the coherent optical communication network, respectively. The integrated transceiver further includes a second optical transceiver portion configured to receive and transmit non-coherent optical signals respectively from and to a non-coherent optical communication network. The integrated transceiver further includes an integrated media access control (MAC) processor disposed between the first and second optical transceiver portions.

Abstract: An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.

Abstract: An echo cancellation method includes steps of (a) extracting phase-distortion estimates, (b) reconstructing an echo signal, (c) generating a clean signal, and (d) producing a primary signal. Step (a) includes extracting, from a first phase signal, a plurality of phase-distortion estimates, the first phase signal having been estimated from an echo-corrupted signal received at a first coherent transceiver of a coherent optical network. Step (b) includes reconstructing an echo signal from the plurality of phase-distortion estimates and a transmitted signal transmitted by the first coherent transceiver. Step (c) includes generating a clean signal as a difference between the reconstructed echo signal and the first phase signal. Step (d) includes producing a primary signal by mapping each of a plurality of clean-phase estimates of the clean signal to one of a plurality of constellation symbols associated with a modulation scheme of the primary signal.

Abstract: A method for generating optical communication signals in a communication network includes (1) generating at least a first optical tone and a second optical tone using a quantum dot (QD) coherent comb laser (CCL), the first and second optical tones having different respective wavelengths, (2) modulating the first optical tone according to a first modulation signal to generate a first communication signal, and (3) modulating the second optical tone according to a second modulation signal to generate a second communication signal.

Abstract: A method for estimating a chromatic dispersion of an optical-fiber channel is disclosed includes receiving, via the optical-fiber channel, a chromatically-dispersed signal having a symbol rate 1/T. The method also includes, for each chromatic-dispersion value of a plurality of chromatic-dispersion values, determining a respective clock-tone magnitude by: (i) applying, to the chromatically-dispersed signal or a signal derived therefrom, a chromatic dispersion equal to the chromatic-dispersion value to generate a dispersion-compensated signal, and (ii) extracting the clock-tone magnitude from at least one of a positive-frequency clock-tone and a negative-frequency clock-tone of the dispersion-compensated signal, the positive-frequency clock-tone and the negative-frequency clock-tone being spectral components of the dispersion-compensated signal at temporal frequencies 1/T or ?1/T respectively. The method also includes determining a maximum of the extracted clock-tone magnitudes.

Abstract: A method for distributed fiber optic sensing (DFOS) includes (a) generating first data signals for transmission via a first fiber optic strand, (b) generating first sensing signals for transmission via the first fiber optic strand, and (c) analyzing at least one of first back-scattering signals and first forward-scattering signals of the first sensing signals, to perform DFOS. The method may further include generating the first sensing signal such that presence of the first sensing signal on the first fiber optic strand does not interfere with transmission of the first data signal by the first fiber optic strand.

Abstract: A full duplex communication network includes an optical transmitter end having a first coherent optics transceiver, an optical receiver end having a second coherent optics transceiver, and an optical transport medium operably coupling the first coherent optics transceiver to the second coherent optics transceiver. The first coherent optics transceiver is configured to simultaneously transmit a downstream optical signal and receive an upstream optical signal. The second coherent optics transceiver is configured to simultaneously receive the downstream optical signal from the first coherent optics transceiver and transmit the upstream optical signal first coherent optics transceiver. At least one of the downstream optical signal and the upstream optical signal includes at least one coherent optical carrier and at least one non-coherent optical carrier.

Abstract: A method is provided for initiating a handover of a wireless device from a first node to a second node in a communication network. The method includes steps of (a) obtaining, at a first time, a (i) speed, (ii) direction, and (iii) first location of the wireless device, (b) determining, relative to the first location, a first signal strength of the second node and a second, higher signal strength of a third node different from the second node, (c) estimating, based on the obtained (i) first location, (ii) speed, and (iii) direction, a second location for the wireless device at a second, subsequent time, (d) confirming that the second location is within a transmission range of the second node, and (e) preempting the handover to the third node by performing, prior to the second time, the handover directly from the first node to the second node.

Abstract: A receiver is provided for processing an input signal from a communication network. The receiver includes a processor and a memory configured to store computer executable instructions, which, when executed by the processor, cause the processor to (i) receive an input data signal including digital bit information, (ii) code the input data signal into a plurality of multi-level symbols, (iii) map the plurality of multi-level symbols into a plurality of constellation points in the phase domain, (iv) execute a first phase recovery subprocess on the plurality of constellation points to recover a first carrier phase of the input signal, (v) implement a Gaussian mixture model (GMM) on the recovered first carrier phase to generate an enhanced recovered carrier phase, and (vi) process the enhanced recovered carrier phase with a second phase recovery subprocess to reduce distortion from the input signal.

Abstract: An optical network includes a transmitting portion configured to (i) encode an input digitized sequence of data samples into a quantized sequence of data samples having a first number of digits per sample, (ii) map the quantized sequence of data samples into a compressed sequence of data samples having a second number of digits per sample, the second number being lower than the first number, and (iii) modulate the compressed sequence of data samples and transmit the modulated sequence over a digital optical link. The optical network further includes a receiving portion configured to (i) receive and demodulate the modulated sequence from the digital optical link, (ii) map the demodulated sequence from the second number of digits per sample into a decompressed sequence having the first number of digits per sample, and (iii) decode the decompressed sequence.

Abstract: A digital receiver is configured to process a polarization multiplexed carrier from a communication network. The polarization multiplexed carrier includes a first polarization and a second polarization. The receiver includes a first lane for transporting a first input signal of the first polarization, a second lane for transporting a second input signal of the second polarization, a dynamic phase noise estimation unit disposed within the first lane and configured to determine a phase noise estimate of the first input signal, a first carrier phase recovery portion configured to remove carrier phase noise from the first polarization based on a combination of the first input signal and a function of the determined phase noise estimate, and a second carrier phase recovery portion configured to remove carrier phase noise from the second polarization based on a combination of the second input signal and the function of the determined phase noise estimate.

Abstract: An optical communication network includes a primary laser source, a first comb generator, and a first transceiver. The first comb generate a first plurality of comb tones having constant frequency spacing. The first transceiver includes a first transmitter having a secondary laser with a resonator frequency injection locked to a frequency of a single longitudinal mode corresponding to a particular comb tone of the first plurality of comb tones. The first transmitter adheres input data onto the injection locked frequency, and outputs a modulated data stream over an optical transport to a second transceiver downstream of the first transceiver. The improvement includes a second comb generator disposed downstream of, receives a seed tone from, and is phase-synchronized with, the first comb generator. The second comb generator outputs a second plurality of comb tones substantially conforming to the frequencies and frequency spacing of the first plurality of comb tones.

Abstract: An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.

Abstract: A beam steering subsystem is provided in an optical communication system. The beam steering subsystem is configured for steering a free-space optical (FSO) beam from a first transceiver to a second transceiver disposed remotely from the first receiver. The beam steering subsystem includes a beam steering device disposed between the first transceiver and the second transceiver, and an optical tracking unit in optical communication and electrical communication with the beam steering device. The wherein the beam steering device is further configured to (i) receive the FSO beam from the first transceiver, (ii) receive an optical tracking signal from the second transceiver, (iii) optically relay the received optical tracking signal to the optical tracking unit, and (iv) steer the FSO beam to the second transceiver based on an electrical feedback control signal from optical tracking unit.

Abstract: An optical full-field transmitter (OFFT) includes a plurality of optical circulators and a polarization beam combiner. The plurality of optical circulators are fabricated on a silicon-on-insulator (SOI) substrate, where each of the optical circulators has (a) a first port that optically couples to a high-quality optical source, (b) a second port that optically couples to a child laser configured to receive amplitude modulation data, and (c) a third port optically coupled to a phase modulator that (i) is configured to receive a phase modulation data and (ii) includes an output port that outputs amplitude and phase modulated light. The polarization beam combiner receives the amplitude and phase modulated light from each of the optical circulators and outputs combined amplitude and phase modulated light.