Provided is a coherent detection implementing apparatus, system and method. The apparatus includes: a first transceiver unit, configured to send an optical signal in a first direction to a second device, wherein the optical signal in the first direction includes a direct current optical signal with a first wavelength and a modulated optical signal with a second wavelength; and configured to receive an optical signal in a second direction from the second device; and a first coherent receiver, connected with the first transceiver unit, and configured to take a part of the direct current optical signal with the first wavelength in the optical signal in the first direction as a Local Oscillator (LO) light for coherent reception, perform coherent frequency mixing between the LO light and the optical signal in the second direction, and demodulate the optical signal in the second direction.

An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.

An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.

Provided is an optical communication device, such as a wavelength locker, a wavelength demultiplexer, an optical coupling system, and an optical switching system, using a small-sized lens element. An optical communication device includes, as a lens element, a liquid crystal diffractive lens element having an optically anisotropic layer that is formed using a composition containing a liquid crystal compound, and has a liquid crystal alignment pattern in which an orientation of an optical axis of the liquid crystal compound changes while continuously rotating toward one direction, in a radial shape from an inside toward an outside, and in the liquid crystal alignment pattern, in a case where a length over which the orientation of the optical axis rotates by 180° in one direction in which the optical axis changes is a single period, a length of the single period gradually decreases from the inside toward the outside.

Provided is an optical communication device, such as a wavelength locker, a wavelength demultiplexer, an optical coupling system, and an optical switching system, using a small-sized lens element. An optical communication device includes, as a lens element, a liquid crystal diffractive lens element having an optically anisotropic layer that is formed using a composition containing a liquid crystal compound, and has a liquid crystal alignment pattern in which an orientation of an optical axis of the liquid crystal compound changes while continuously rotating toward one direction, in a radial shape from an inside toward an outside, and in the liquid crystal alignment pattern, in a case where a length over which the orientation of the optical axis rotates by 180° in one direction in which the optical axis changes is a single period, a length of the single period gradually decreases from the inside toward the outside.

A system for laser phase noise compensation for a fibered communication path, the system being configured for connection with a node of the fibered communication path, including at least one signal splitter optically coupled to a laser source of the fibered communication path, the at least one signal splitter having two output communication path, the communication paths having a path difference therebetween; an integrated coherent receiver (ICR) optically coupled to the first output communication path and the second output communication path; and a digital signal processor (DSP) communicatively connected to the ICR, the ICR being configured to determine, based signals received from the first and second output communication paths, at least one phase noise indication related to phase noise of the laser source, the DSP being configured to determine an estimated laser phase noise based on at least the at least one phase noise indication.

A method for transmitting data carrying optical information over an optical channel, comprising the steps of providing an optical transmitter consisting of a light source being a Mode-Locked Optical Frequency Comb (MLFC) for generating a frequency comb of multiple carriers, each of which being modulated by a baseband signal; an optical modulator for modulating each and all of the multiple carriers in a modulation bandwidth extending up to the modes' frequency spacing between the multiple carriers; performing all-optical encoding of the modulated carriers by manipulating the optical amplitude and/or phase and/or polarization of all optically modulated carriers; and transmitting, by the optical transmitter, the encoded modulated carriers to an optical receiver, over an optical channel

A communication network includes a coherent optics transmitter, a coherent optics receiver, an optical transport medium operably coupling the coherent optics transmitter to the coherent optics receiver, and a coherent optics interface. The coherent optics interface includes a lineside interface portion, a clientside interface portion, and a control interface portion.

A communication network includes a coherent optics transmitter, a coherent optics receiver, an optical transport medium operably coupling the coherent optics transmitter to the coherent optics receiver, and a coherent optics interface. The coherent optics interface includes a lineside interface portion, a clientside interface portion, and a control interface portion.

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.