Techniques are described for providing a hybrid compensation of chromatic dispersion in optical networks to reduce power consumption by coherent receivers. In some examples, a controller may receive a chromatic dispersion value of an optical signal from a coherent receiver integrated with a receiver optical network device. The controller may compare the chromatic dispersion value with a threshold. The controller may, in response to determining that the chromatic dispersion value satisfies the threshold, perform at least one of: configure a switch connected to a dispersion compensation module (DCM) with a state to provide access to the DCM to compensate the chromatic dispersion value of the optical signal, or adjust a phase response of a filter of a coherent transmitter to compensate the chromatic dispersion value of the optical signal.

Apparatus and method for digital signal constellation transformation are provided herein. In certain configurations, an integrated circuit includes an analog front-end that converts an analog signal vector representing an optical signal into a digital signal vector, and a digital signal processing circuit that processes the digital signal vector to recover data from the optical signal. The digital signal processing circuit generates signal data representing a signal constellation of the digital signal vector. The digital signal processing circuit includes an adaptive gain equalizer that compensates the signal data for distortion of the signal constellation arising from biasing errors of optical modulators used to transmit the optical signal.

Apparatus and method for digital signal constellation transformation are provided herein. In certain configurations, an integrated circuit includes an analog front-end that converts an analog signal vector representing an optical signal into a digital signal vector, and a digital signal processing circuit that processes the digital signal vector to recover data from the optical signal. The digital signal processing circuit generates signal data representing a signal constellation of the digital signal vector. The digital signal processing circuit includes an adaptive gain equalizer that compensates the signal data for distortion of the signal constellation arising from biasing errors of optical modulators used to transmit the optical signal.

The invention provides a method for nonlinear compensation of coherent high-capacity high-order QAM system, including: deploying an OPC on an intermediate link of communication between a transmitter and receiver, and performing phase conjugation on a transmitted signal based on the OPC to generate idler; performing phase recovery on a compensated signal at the receiver to obtain a constellation diagram, simulating a nonlinear function relationship between a transmitted signal and a received signal by using a trained and learned CVDNN, and performing nonlinear compensation on the constellation diagram to obtain the compensated constellation diagram; and calculating a Q-factor based on the compensated constellation diagram, and evaluating communication performance by the Q-factor. Nonlinear compensation is performed on a transmitted signal by using an OPC+CVDNN method to equalize nonlinear degradation of an optical fiber in a WDM coherent optical communication system.

A method and apparatus for compensating optical dispersion over an optical fiber are provided in fiber optic communications to increase a transmission distance by overcoming the optical dispersion caused by wavelength changes of light sources and dispersion effects of a fiber. In one implementation, the present technology may be implemented in the form of a RLC passive microwave filter with no extra power consumption. By way of example, an optical receiver may include a photodiode operable to receive an optical signal and produce an electrical signal, a transimpedance amplifier (TIA) operable to receive the electrical signal and produce a first amplified signal, and an electronic dispersion compensation (EDC) device operable to receive the first amplifier signal from the TIA and compensate or reduce the effects of optical dispersion on the received electrical signal.

An optical signal receiver includes a multimode waveguide for receiving a complex modulated optical signal, an optical resonator that receives the complex modulated optical signal from the multimode waveguide and converts the complex modulated optical signal to an intensity modulated signal, and a detector that is configured to convert the intensity modulated signal into an electrical signal, the electrical signal having an amplitude indicative of an intensity of the intensity modulated signal from the optical resonator, and that provides a detected signal.

The invention provides a method for nonlinear compensation of coherent high-capacity high-order QAM system, including: deploying an OPC on an intermediate link of communication between a transmitter and receiver, and performing phase conjugation on a transmitted signal based on the OPC to generate idler; performing phase recovery on a compensated signal at the receiver to obtain a constellation diagram, simulating a nonlinear function relationship between a transmitted signal and a received signal by using a trained and learned CVDNN, and performing nonlinear compensation on the constellation diagram to obtain the compensated constellation diagram; and calculating a Q-factor based on the compensated constellation diagram, and evaluating communication performance by the Q-factor. Nonlinear compensation is performed on a transmitted signal by using an OPC+CVDNN method to equalize nonlinear degradation of an optical fiber in a WDM coherent optical communication system.

A system and method for mitigating nonlinearity in an optical communication link with multiple carriers uses mutual frequency referencing to stabilize at least a portion of the multiple carriers. Using at least one frequency-referenced signal, carrier nonlinearity can be determined and compensated within the link by pre-distortion, back-propagation, or a combination of both. Mutual frequency referencing may be performed at the emitting end of the link, at the receiving end, or a combination of both.

An optical communication system includes a transmitter and at least one receiver employing a feature of an outdoor environment, or includes a transmitter and a receiver in each of multiple transceivers employing a respective or shared feature of the outdoor environment. The transmitter includes a laser emitting a beam of laser pulses having a wavelength. The transmitter encodes data into the laser pulses in the beam, and transmits the beam of laser pulses through free space of the outdoor environment and then onto a feature of the outdoor environment. Each receiver includes a line filter blocking light not having the wavelength. The receiver decodes data from the light that passes through the line filter and includes a diffusion of the beam from the feature.

An optical signal receiver includes a multimode waveguide for receiving a complex modulated optical signal, an optical resonator that receives the complex modulated optical signal from the multimode waveguide and converts the complex modulated optical signal to an intensity modulated signal, and a detector that is configured to convert the intensity modulated signal into an electrical signal, the electrical signal having an amplitude indicative of an intensity of the intensity modulated signal from the optical resonator, and that provides a detected signal.