Provided is an optical transmission system that includes: a transponder having a transmitter and a receiver; a loopback path that directly couples a signal of the transmitter to the receiver; and a server that calculates, based on a signal transmitted using the loopback path, a compensation value to compensate for frequency characteristics of a signal transmitted from the transmitter.

The disclosure relates to a method, an optical receiver and an optical system for compensating, at an optical receiver, signal distortions induced in an optical carrier signal by a periodic copropagating optical signal, wherein the optical carrier signal and the copropagating signal copropagate at least in part of an optical system or network, by: receiving, at the optical receiver, the optical carrier signal, wherein the optical carrier signal is distorted by the copropagating signal; determining, at the optical receiver, a period of a periodic component of the distorted optical carrier signal; determining, at the optical receiver, a periodic distortion of the distorted optical carrier signal; and generating a compensation signal to correct the distorted optical carrier signal according to the determined periodic distortion.

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 communication interface comprising a host with non-linear equalizers configured to perform non-linear equalization. Also part of the interface is a host to optic module channel electrically connecting the host to an optic module and the optic module. The optic module comprises a transmitter and a receiver. The transmitter includes a linear equalizer and an electrical to optical module configured to convert the equalized signal from the driver to an optical signal, and transmit the optical signal over a fiber optic cable, such that the transmitter does not perform non-linear processing. The receiver includes a photodetector, configured to convert the received optic signal to a received electrical signal, and a linear amplifier configured to perform linear amplification on the received electrical signal. A driver sends the amplified received signal over an optic module to host channel, such that the receive does not perform non-linear processing.

Cost-effective high-data-rate optical data transceivers are presented, comprising an electronic analog transversal filter simultaneously providing one or more of bandwidth compensation and forward impairment compensations for the transmitted optical signal.

A communication interface comprising a host with non-linear equalizers configured to perform non-linear equalization. Also part of the interface is a host to optic module channel electrically connecting the host to an optic module and the optic module. The optic module comprises a transmitter and a receiver. The transmitter includes a linear equalizer and an electrical to optical module configured to convert the equalized signal from the driver to an optical signal, and transmit the optical signal over a fiber optic cable, such that the transmitter does not perform non-linear processing. The receiver includes a photodetector, configured to convert the received optic signal to a received electrical signal, and a linear amplifier configured to perform linear amplification on the received electrical signal. A driver sends the amplified received signal over an optic module to host channel, such that the receive does not perform non-linear processing.

Presented herein are methodologies for using legacy optical fiber for 10 Gigabit Ethernet or higher data rates. The methodology includes obtaining an electrical signal derived from optical-to-electrical conversion of an optical signal that was transmitted over, and received from, an optical fiber; and applying an equalization process to the electrical signal, wherein the equalization process is of a type that is designed to equalize received signals that were transmitted via a copper cable.

A receiver system is provided for receiving a coherent Pulse Amplitude Modulation (PAM) encoded signal. The receiver system may include an optical polarization component configured to modulate a polarization of the received coherent PAM encoded signal. The receiver system may further include a digital signal processor (DSP) configured to perform polarization recovery between the received coherent PAM encoded signal and the LO signal using a first control loop, and to perform phase recovery between the received coherent PAM encoded signal and the LO signal using a second control loop.

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.