Abstract: A system and method for wavelength detection includes one or more detection stages configured for receiving at least a portion of an optical carrier. Each stage includes a splitter for splitting the signal into two arms. A 90-degree optical hybrid and in-phase (I-channel)/quadrature (Q-channel) differential detectors generate I-channel and Q-channel differential signals based on the hybrid outputs. A gas cell or like multi-point wavelength reference path also receives the input signal and provides a set of reference absorption wavelengths converted into the electrical domain by a reference photodetector. A logic device receives sets of detection signals (including I-channel and Q-channel differential signals and the set of reference wavelengths, all corresponding to a common measurement time) and determines a wavelength of the optical carrier based on an arctangent of a ratio of the Q-channel and I-channel differential signals, mapped to the set of reference absorption wavelengths.

Abstract: A system is described. The system includes HNLF for generating an optical frequency comb and a single mode fiber for reducing a pulse duration of comb. The system includes a FRM to reflect the light in back propagation through the HNLF and the single mode fiber. Perturbations in a state of polarization caused by the HNLF and the single mode fiber are cancelled between the forward propagation and the backward propagation. The optical frequency comb may then be polarization maintaining without an active component such as a polarization controller and a feedback circuit.

Abstract: A system is described. The system includes HNLF for generating an optical frequency comb and a single mode fiber for reducing a pulse duration of comb. The system includes a FRM to reflect the light in back propagation through the HNLF and the single mode fiber. Perturbations in a state of polarization caused by the HNLF and the single mode fiber are cancelled between the forward propagation and the backward propagation. The optical frequency comb may then be polarization maintaining without an active component such as a polarization controller and a feedback circuit.

Abstract: A system and method for wavelength detection includes one or more detection stages configured for receiving at least a portion of an optical carrier. Each stage includes a splitter for splitting the signal into two arms. A 90-degree optical hybrid and in-phase (I-channel)/quadrature (Q-channel) differential detectors generate I-channel and Q-channel differential signals based on the hybrid outputs. A gas cell or like multi-point wavelength reference path also receives the input signal and provides a set of reference absorption wavelengths converted into the electrical domain by a reference photodetector. A logic device receives sets of detection signals (including I-channel and Q-channel differential signals and the set of reference wavelengths, all corresponding to a common measurement time) and determines a wavelength of the optical carrier based on an arctangent of a ratio of the Q-channel and I-channel differential signals, mapped to the set of reference absorption wavelengths.

Abstract: A photonic processor includes a modulator, an optical filter, and a polarization combiner. The modulator is configured to receive an electronic signal, first optical control signal, and first optical operating signal, the first optical operating signal received from an optical source circuit on a first path having a first length, the first optical control signal received from an optical control circuit on the first path; modulate the first optical operating signal using the electronic signal to provide an intensity-modulated optical operating signal comprising a first optical operating carrier, first sideband, and second sideband; and modulate the first optical control signal using the electronic signal to provide an intensity-modulated control signal comprising a first optical control carrier. The optical filter is configured to extract the first optical operating carrier and first sideband from the intensity-modulated optical operating signal and provide the second sideband and the control carrier.

Abstract: A method of performing optical serial-to-parallel conversion of an optical signal includes performing phase modulation of the optical pulse stream and outputting a phase-modulated optical signal as a result thereof. The method also includes performing optical switching of the phase-modulated optical signal by optical switches connected to each other in a series relationship on a signal path. The method further includes performing optical switching of a reference optical clock signal by optical switches connected to each other in a series relationship on a reference path.

Abstract: A method and related system for linearizing a photonic ADC sampling system of an ELINT receiver includes modulating optical pulse trains of varied pulse amplitudes based on a generated ramped-voltage calibration signal. The modulated pulse trains are demodulated into I/Q components to generate signal constellations. Equivoltage radials are defined by points of the signal constellations sharing a common calibration voltage and a common phase angle of the modulator. A lookup table is generated by mapping the signal constellations and equivoltage radials to a coordinate system to determine, for each coordinate bin, a corresponding pulse amplitude and phase angle. The generated lookup table may be used to correct nonlinear distortions in recovered output signals, preserving high-ENOB performance and increasing the dynamic range of the receiver.

Abstract: A mode-locked laser has optical components integrated into a single apparatus and interrelated via optical free-space coupling. The laser optical cavity path is reduced to less than ten meters, primarily composed of optical gain fiber. A Fabry-Perot filter is matched to the laser pulse repetition frequency. Utilizing a Fabry-Perot filter within the laser optical cavity suppresses supermode spurs in the phase noise spectrum; thereby reducing total timing jitter.

Abstract: A communication system may include a first control circuit to detect a break on a first optical link; a first optical source to supply a first optical signal on a second optical link in response to detecting the break on the first optical link, the first optical signal propagating in a first direction on the second optical link; a second control circuit to detect a presence of the first optical signal on the second optical link, and output a control signal in response to detecting the presence of the first optical signal; and a second optical source to supply a second optical signal on the second optical link, the second optical signal propagating in a second direction opposite the first direction, where the Raman pump is disabled in response to the control signal.

Abstract: A method of and system of processing a phase-modulated optical signal includes performing, by demodulators, demodulation of the phase-modulated optical signal and outputting optical demodulated signals. The processing further includes performing, by pairs of gated photo detectors respectively connected to the I/Q demodulators, photo detection of the demodulated signals. The processing further tracks and holds electronicversions of the demodulated signals with a track and hold amplifier.

Abstract: A system and method of digitizing an analog signal without an amplitude channel is disclosed. The system and method includes receiving an analog signal comprising a voltage v(t) and a frequency f1, producing a series of optical pulses at a sampling frequency f2 with a pulsed laser, splitting the series of optical pulses into a first optical signal and an optical reference signal, phase modulating the first optical signal with the analog signal to produce a sampled optical signal such that phase shifts between adjacent samples in the sampled optical signal does not exceed ? radians, and receiving the sampled optical signal and the optical reference signal at a photonic signal processor.

Abstract: An analog signal receiver includes photonic sampling and electronic quantization. The receiver includes timing control circuitry configured to receive a series of optical pulses and output a plurality of timing signals based on the series of optical pulses to synchronize optical switches that receive a sampled optical signal to time deinterleave the optically sampled signal. The time deinterleaved signals are then sent to a plurality of demodulators wherein each demodulator receives at least one time deinterleaved optically sampled signal and at least one time deinterleaved optical reference signal to produce electrical signals based on the demodulated optical signals.

Abstract: A method of performing optical serial-to-parallel conversion of an optical signal includes performing phase modulation of the optical pulse stream and outputting a phase-modulated optical signal. Optical switching of the phase-modulated optical signal is performed by optical switches provided on a signal path. Optical switching of a reference optical clock signal is performed by optical switches provided on a reference path. I/Q demodulation of the optically switched phase-modulated optical signal respectively output by an optical switch is performed on the signal path at timings corresponding to the optically switched reference optical clock signal respectively output by an optical switch on the reference path, in which I and Q demodulated signals are output as a result thereof. Photodetection of the I and Q demodulated signals is then performed.

Abstract: A communication system may include a first control circuit to detect a break on a first optical link; a first optical source to supply a first optical signal on a second optical link in response to detecting the break on the first optical link, the first optical signal propagating in a first direction on the second optical link; a second control circuit to detect a presence of the first optical signal on the second optical link, and output a control signal in response to detecting the presence of the first optical signal; and a second optical source to supply a second optical signal on the second optical link, the second optical signal propagating in a second direction opposite the first direction, where the Raman pump is disabled in response to the control signal.

Abstract: Optical transmission systems of the present invention include at least one optical amplifier generally including an optical signal amplifying medium supplied with pump power in the form of optical energy in via an optical pump source. The pump source includes multiple optical sources, at least two of which provide optical energy in first and second wavelength ranges separated by a frequency difference. The amplifier includes a wavelength controller configured to adjust the wavelength range of at least one of the optical sources to vary the frequency difference in a manner sufficient to vary optical intensity noise produced when the optical energy from the multiple optical sources is combined.

Abstract: Optical transmission systems of the present invention include at least one optical amplifier generally including an optical signal amplifying medium supplied with pump power in the form of optical energy in via an optical pump source. The pump source includes multiple optical sources, at least two of which provide optical energy in first and second wavelength ranges separated by a frequency difference. The amplifier includes a wavelength controller configured to adjust the wavelength range of at least one of the optical sources to vary the frequency difference in a manner sufficient to vary optical intensity noise produced when the optical energy from the multiple optical sources is combined.

Abstract: Optical transmission systems of the present invention include at least one optical amplifier generally including an optical signal amplifying medium supplied with pump power in the form of optical energy in via an optical pump source. The pump source includes multiple optical sources, at least two of which provide optical energy in first and second wavelength ranges separated by a frequency difference. The amplifier includes a wavelength controller configured to adjust the wavelength range of at least one of the optical sources to vary the frequency difference in a manner sufficient to vary optical intensity noise produced when the optical energy from the multiple optical sources is combined.

Abstract: Optical transmission systems of the present invention include at least one optical amplifier generally including an optical signal amplifying medium supplied with pump power in the form of optical energy in via an optical pump source. The pump source includes multiple optical sources, at least two of which provide optical energy in first and second wavelength ranges separated by a frequency difference. The amplifier includes a wavelength controller configured to adjust the wavelength range of at least one of the optical sources to vary the frequency difference in a manner sufficient to vary optical intensity noise produced when the optical energy from the multiple optical sources is combined.