Methods and systems for low complexity interference cancellation in multichannel optical transmission. Local or self-iteration is performed one or more times between an expected propagation decision feedback equalizer and a soft demapper. Following local iteration, a soft decision forward error correction decoder determines bit log-likelihood ratios, which are fed back to the expected propagation decision feedback equalizer and soft demapper for further self-iteration. Global iteration involving the decoder can also be performed one or more times before a bitstream is decoded.

Described herein are photonic integrated circuits (PICs) comprising a semiconductor optical amplifier (SOA) to output a signal comprising a plurality of wavelengths, a sensor to detect data associated with a power value of each wavelength of the output signal of the SOA, a filter to filter power values of one or more of the wavelengths of the output signal of the SOA, and control circuitry to control the filter to reduce a difference between a pre-determined power value of each filtered wavelength of the output signal of the SOA and the detected power value of each filtered wavelength of the output signal of the SOA.

This application provides example signal processing apparatus and example signal processing method. One example signal processing apparatus includes a sampling unit, a beam combiner, and an optical resonator. The sampling unit is connected to the beam combiner, and the beam combiner is connected to the optical resonator. The sampling unit is configured to sample an analog signal by using an optical pulse signal to output a sampled optical pulse signal. The beam combiner is configured to combine the sampled optical pulse signal and a multi-wavelength optical signal into a first optical signal. The optical resonator is configured to perform resonance based on the first optical signal to output a second optical signal in the first optical signal, where a wavelength of the second optical signal is equal to a resonant wavelength of the optical resonator.

An optical data communication system includes an optical power supply and an electro-optical chip. The optical power supply includes a laser that generates laser light at a single wavelength. A comb generator receives the light at the single wavelength and generates multiple wavelengths of continuous wave light from laser light at the single wavelength. The multiple wavelengths of continuous wave light are provided as light input to the electro-optical chip. The electro-optical chip includes at least one transmit macro that receives the multiple wavelengths of continuous wave light and that modulates one or more of the multiple wavelengths of continuous wave light to generate modulated light signals that convey digital data.

Systems and methods for increasing throughput of a photonic processor by using photonic degrees of freedom (DOF) are provided. The photonic processor includes a multiplexer configured to multiplex, using at least one photonic DOF, multiple encoded optical signals into a multiplexed optical signal. The photonic processor also includes a detector coupled to an output of an optical path including the multiplexer, the detector being configured to generate a first current based on the multiplexed optical signal or a demultiplexed portion of the multiplexed optical signal. The photonic processor further includes a modulator coupled to and output of the detector, the modulator being configured to generate a second current by modulating the first current.

A wavelength multiplexing/demultiplexing device includes a first collimator, an M number of second collimators, and the M number of filters. The filters have transmission wavelength bands differing from each other. An optical path connecting the first collimator and the second collimator in first order to each other passes through the filter in first order. An optical path connecting a surface opposite to a multilayer film of the filter in mth (m=1, . . . , M) order and the second collimator in (m+1)th order to each other passes through the filter in (m+1)th order. The filter in (m+1)th order is optically coupled on the surface opposite to the multilayer film to the filter in mth order and is optically coupled on a surface of the multilayer film to the second collimator in (m+1)th order.

In a coherent optical receiver device, the dynamic range considerably decreases in the case of selectively receiving the optical multiplexed signals by means of the wavelength of the local oscillator light, therefore, a coherent optical receiver device according to an exemplary aspect of the invention includes a coherent optical receiver receiving optical multiplexed signals in a lump in which signal light is multiplexed; a variable optical attenuator; a local oscillator connected to the coherent optical receiver; and a first controller controlling the variable optical attenuator by means of a first control signal based on an output signal of the coherent optical receiver; wherein the coherent optical receiver includes a 90-degree hybrid circuit, a photoelectric converter, and an impedance conversion amplifier, and selectively detects the signal light interfering with local oscillation light output by the local oscillator out of the optical multiplexed signals; and the variable optical attenuator is disposed in the optical path of the optical multiplexed signals in a stage preceding the photoelectric converter, inputs the optical multiplexed signals, and outputs them to the coherent optical receiver controlling the intensity of the optical multiplexed signals based on the first control signal.

In a coherent optical receiver device, the dynamic range considerably decreases in the case of selectively receiving the optical multiplexed signals by means of the wavelength of the local oscillator light, therefore, a coherent optical receiver device according to an exemplary aspect of the invention includes a coherent optical receiver receiving optical multiplexed signals in a lump in which signal light is multiplexed; a variable optical attenuator; a local oscillator connected to the coherent optical receiver; and a first controller controlling the variable optical attenuator by means of a first control signal based on an output signal of the coherent optical receiver; wherein the coherent optical receiver includes a 90-degree hybrid circuit, a photoelectric converter, and an impedance conversion amplifier, and selectively detects the signal light interfering with local oscillation light output by the local oscillator out of the optical multiplexed signals; and the variable optical attenuator is disposed in the optical path of the optical multiplexed signals in a stage preceding the photoelectric converter, inputs the optical multiplexed signals, and outputs them to the coherent optical receiver controlling the intensity of the optical multiplexed signals based on the first control signal.

According to an example aspect of the present invention, there is provided an apparatus comprising a first part (110) which comprises a first light-based communication port (114) and a network interface (112), a second part (120) which comprises a non-volatile memory (122) and a second light-based communication port (124), and wherein the apparatus is configured to deactivate at least one of the first light-based communication port (114) and the second light-based communication port (124) responsive to determining that a read or write operation in the non-volatile memory (122) is complete.

A multi-layer network planning system can determine a set of regenerator sites (“RSs”) that have been found to cover all paths among a set of nodes of an optical layer of a multi-layer network and can determine a set of candidate RSs in the optical layer for use by the links between a set of nodes of an upper layer, wherein each RS can be selected as a candidate RS for the links. The system can determine a binary path matrix for the links between the set of nodes of the upper layer. The system can determine a min-cost matrix that includes a plurality of min-cost paths. The system can determine a best RS from the set of candidate RSs and can move the best RS from the set of candidate RSs into the set of RSs for the links. The system can then update the binary path matrix.