A remote unit includes: an optical module configured to receive a signal from an access unit communicatively connected to the remote unit; a power distribution module connected to the optical module and configured to divide the signal received from the optical module into a first component and a second component, the second component having a working band different from that of the first component; a first low noise and high-power amplifier connected to the power distribution module and configured to process the first component; and a second low noise and high-power amplifier connected to the power distribution module and configured to process the second component.

Systems and methods are described for transmitting information optically. For instance, a system may include an optical source configured to generate a beam of light. The system may include at least one modulator configured to encode data on the beam of light to produce an encoded beam of light/encoded plurality of pulses. The system may include a spectrally-equalizing amplifier configured to receive the encoded beam of light/encoded plurality of pulses from the at least one modulator and both amplify and filter the encoded beam of light/encoded plurality of pulses to produce a filtered beam of light/filtered plurality of pulses, thereby spectrally equalizing a gain applied to the encoded beam of light. In some cases, the system may slice the beam of slight, to ensure a detector has impulsive detection. In some cases, the system may include a temperature controller to shift a distribution curve of wavelengths of the optical source.

A method for operating an optical demodulator includes receiving a double sideband suppressed carrier (DSBSC) optical signal. The method further includes passing the DSBSC optical signal through a Costas loop circuit. The method further includes outputting a radio frequency (RF) signal from a quadrature port of the Costas loop circuit.

Systems and methods are described for transmitting information optically. For instance, a system may include an optical source configured to generate a beam of light. The system may include at least one modulator configured to encode data on the beam of light to produce an encoded beam of light/encoded plurality of pulses. The system may include a spectrally-equalizing amplifier configured to receive the encoded beam of light/encoded plurality of pulses from the at least one modulator and both amplify and filter the encoded beam of light/encoded plurality of pulses to produce a filtered beam of light/filtered plurality of pulses, thereby spectrally equalizing a gain applied to the encoded beam of light. In some cases, the system may slice the beam of slight, to ensure a detector has impulsive detection. In some cases, the system may include a temperature controller to shift a distribution curve of wavelengths of the optical source.

An optical receiver includes an error generator, a multipath interference estimator, and a combiner. The error generator is configured to receive an input comprising a received optical signal, to estimate a modulation level of samples of the received optical signal, and to generate an error signal based on the estimated modulation level of the samples, the error signal representing a difference between an actual level of the received optical signal and the estimated modulation level. The multipath interference estimator is configured to generate estimates of multipath interference (MPI) associated with the samples of the received optical signal based on the error signal. The combiner is configured to generate an MPI-mitigated signal based on a combination of the samples and the estimates of MPI.

An optical module configured to electrically connect to a host. A linear equalizer performs equalization on a host equalized signal to create a module equalized signal, and a driver configured to present the module equalized signal from the linear equalizer to an optical conversion device at a magnitude suitable for the optical conversion device. An optical conversion device receives the module equalized signal from the driver, converts the module equalized signal to an optical signal, and transmit the optical signal over an optical channel. Also part of the optical module is an interface which communicates supplemental equalizer settings to the host. A memory stores the supplemental equalizer settings which reflect the optical modules effect on a signal passing through the optical module. A controller oversees communication of the supplemental equalizer settings to the host such that the host uses the supplemental equalizer settings to modify host equalizer settings.

An optical module configured to electrically connect to a host. A linear equalizer performs equalization on a host equalized signal to create a module equalized signal, and a driver configured to present the module equalized signal from the linear equalizer to an optical conversion device at a magnitude suitable for the optical conversion device. An optical conversion device receives the module equalized signal from the driver, converts the module equalized signal to an optical signal, and transmit the optical signal over an optical channel. Also part of the optical module is an interface which communicates supplemental equalizer settings to the host. A memory stores the supplemental equalizer settings which reflect the optical modules effect on a signal passing through the optical module. A controller oversees communication of the supplemental equalizer settings to the host such that the host uses the supplemental equalizer settings to modify host equalizer settings.

Systems and methods are described for transmitting information optically. For instance, a system may include an optical source configured to generate a beam of light. The system may include at least one modulator configured to encode data on the beam of light to produce an encoded beam of light/encoded plurality of pulses. The system may include a spectrally-equalizing amplifier configured to receive the encoded beam of light/encoded plurality of pulses from the at least one modulator and both amplify and filter the encoded beam of light/encoded plurality of pulses to produce a filtered beam of light/filtered plurality of pulses, thereby spectrally equalizing a gain applied to the encoded beam of light. In some cases, the system may slice the beam of slight, to ensure a detector has impulsive detection. In some cases, the system may include a temperature controller to shift a distribution curve of wavelengths of the optical source.

The method includes receiving, at a first optical communication device, feedback information on training of a neural network from at least one second optical communication device, the neural network configured to process a signal received from the first optical communication device, the feedback information at least including a training performance indication for training of the neural network conducted at the at least one second optical communication device; updating, based on the feedback information, a first initial parameter value set for the neural network maintained at the first optical communication device, to obtain a second initial parameter value set for the neural network; and transmitting the second initial parameter value set to at least one further second optical communication device, for training of the neural network to be conducted at the at least one further second optical communication device based on the second initial parameter value set.

Technologies for optical equalizers with metasurfaces are disclosed. In an illustrative embodiment, an optical equalizer can be formed from two metasurfaces. The metasurfaces reflect light in different directions depending on the spatial mode of the light. The metasurfaces can be used to change the optical path length of different modes of light from an optical input to an optical output, such as from an optical fiber to a photodiode. The optical equalizer can delay some modes of light relative to other modes, partially or fully compensating for mode dispersion in a multi-mode optical fiber.