A system includes a transmitter configured to output an optical signal. The transmitter includes a seed laser, an optical array including a plurality of array elements, and a plurality of phase shifters in a multi-layer arrangement. The multi-layer arrangement includes a plurality of layers between the seed laser and the optical array, wherein a first layer of the plurality of layers transmits light to a second layer of the plurality of layers. The first layer has fewer phase shifters than the second layer. The multi-layer arrangement also includes a plurality of branches wherein each branch includes a phase shifter from each of the plurality of layers connected in series between the seed laser and one of the plurality of array elements. Each phase shifter is configured to shift the optical signal incrementally to amass a total phase shift for each of the plurality of array elements.

This disclosure describes digitally generating sub-carriers (SCs) to provide isolation and dynamic allocation of bandwidth between uplink and downlink traffic between transceivers that are communicatively coupled via a bidirectional link including one or more segments of optical fiber. Separate uplink and downlink communication channels may be created using digitally generated SCs and using the same transmitter laser. In some implementations, one or more of the nodes include a transceiver having at least one laser and one digital signal processing (DSP) operable for digitally generating at least two SCs and detecting at least two SCs. The transceiver can transmit selected SCs, and can receive other SCs. Accordingly, the transceiver can facilitate bidirectional communication, for example, over a single optical fiber link. In some instances, techniques can facilitate dynamic bandwidth assignment by facilitating adding or blocking of optical subcarriers from transmission in an uplink or downlink direction.

An interferometric demodulation system for a large capacity fiber grating sensing network is provided by the present disclosure, comprising: a continuous light output end of the nanoscale wide-spectrum light source is connected to an input end of the pulse optical modulator, an output end of the reference grating is connected to an input end of the grating array sensing network, and a third communication end of the optical circulator is connected to an input end of the optical amplifier, an output end of the optical amplifier is connected to an input end of the Mach-Zehnder interferometer, three-channel signal output ends of the Mach-Zehnder interferometer are respectively connected to signal input ends corresponding to the embedded signal processor through the photoelectric converter, and the embedded signal processor controls the heating device to control a temperature of an any one of interference arms of the Mach-Zehnder interferometer.

An interferometric demodulation system for a large capacity fiber grating sensing network is provided by the present disclosure, comprising: a continuous light output end of the nanoscale wide-spectrum light source is connected to an input end of the pulse optical modulator, an output end of the reference grating is connected to an input end of the grating array sensing network, and a third communication end of the optical circulator is connected to an input end of the optical amplifier, an output end of the optical amplifier is connected to an input end of the Mach-Zehnder interferometer, three-channel signal output ends of the Mach-Zehnder interferometer are respectively connected to signal input ends corresponding to the embedded signal processor through the photoelectric converter, and the embedded signal processor controls the heating device to control a temperature of an any one of interference arms of the Mach-Zehnder interferometer.

According to the present disclosure, it is possible to realize an optical communication system in which a relay-type PSA and homodyne detection are efficiently combined using a single phase synchronization mechanism. Intensity noise and phase noise can be suppressed to a very low level, and accurate transmission of signals with increased multiplicity is enabled. By utilizing the features of the PSA to extract the phase of a single carrier using the sum frequency light of the signal light and its phase-conjugated light, the number of pilot carriers can be reduced compared to the configuration of the conventional optical communication system, and it is possible to suppress unnecessary nonlinear noise.

According to the present disclosure, it is possible to realize an optical communication system in which a relay-type PSA and homodyne detection are efficiently combined using a single phase synchronization mechanism. Intensity noise and phase noise can be suppressed to a very low level, and accurate transmission of signals with increased multiplicity is enabled. By utilizing the features of the PSA to extract the phase of a single carrier using the sum frequency light of the signal light and its phase-conjugated light, the number of pilot carriers can be reduced compared to the configuration of the conventional optical communication system, and it is possible to suppress unnecessary nonlinear noise.

A power sourcing equipment includes a laser oscillator and a modulator. The laser oscillator converts electric power into feed light. The modulator modulates, based on transmission information, a phase of the feed light output from the laser oscillator. The feed light phase-modulated by the modulator is output to outside of the power sourcing equipment. A powered device includes a photoelectric conversion element and a demodulator. The photoelectric conversion element converts feed light input from outside of the powered device into electric power. The demodulator detects a phase of the feed light to restore transmission information.

A power sourcing equipment includes a laser oscillator and a modulator. The laser oscillator converts electric power into feed light. The modulator modulates, based on transmission information, a phase of the feed light output from the laser oscillator. The feed light phase-modulated by the modulator is output to outside of the power sourcing equipment. A powered device includes a photoelectric conversion element and a demodulator. The photoelectric conversion element converts feed light input from outside of the powered device into electric power. The demodulator detects a phase of the feed light to restore transmission information.

A High Bandwidth Individual Channel Control via Optical Reference Interferometry (HICCORI) system actively controls the phase and/or polarization of the optical emission of each element in a tiled optical array. It can also actively align any high-frequency broadening waveform applied to the array beams for spectral broadening or data transmission. By maintaining consistent polarization and manipulating the phase relationships of the beams emitted by the array elements, the HICCORI system can manipulate the spatial pattern of constructive and destructive interference formed as the individual emissions coherently combine. Active feedback control allows the desired phase, polarization, and/or spectral broadening alignment to be maintained in the presence of external disturbances.

A High Bandwidth Individual Channel Control via Optical Reference Interferometry (HICCORI) system actively controls the phase and/or polarization of the optical emission of each element in a tiled optical array. It can also actively align any high-frequency broadening waveform applied to the array beams for spectral broadening or data transmission. By maintaining consistent polarization and manipulating the phase relationships of the beams emitted by the array elements, the HICCORI system can manipulate the spatial pattern of constructive and destructive interference formed as the individual emissions coherently combine. Active feedback control allows the desired phase, polarization, and/or spectral broadening alignment to be maintained in the presence of external disturbances.