A protection method wherein an ONU switches a reception wavelength to a backup wavelength so as to be logically connected to a backup OSU designated in advance for each ONU when the ONU detects a failure in an OSU to which the ONU is originally assigned, while the ONU keeps on holding its own connection information with the OLT. In the OLT, a backup OSU for the ONU which is originally assigned to the failed OSU is notified of the information on the ONU when the OLT detects a failure in an OSU. In this way, the ONUs which are originally assigned to the failed OSU resumes communication in a short period.

An optical add/drop multiplexer branching apparatus is provided in the embodiments of the present invention, where the optical add/drop multiplexer branching unit includes: a trunk input end, a branch input end, a trunk output end, a branch output end, an optical add/drop multiplexer, a first coupler, a first detection circuit, and a control circuit, where the optical add/drop multiplexer includes an optical switch. A detection circuit detects whether a fault occurs in a trunk, and in a case in which a fault occurs in the trunk, a working mode is switched from a first working mode to a second working mode, to implement automatic redundancy on the trunk and ensure normal communication on a branch.

In at least one aspect, a device for Orbital Angular Momentum (OAM) based optical communication includes a first spatial light modulator configured to down-convert a first plurality of higher-order OAM modes from a communication signal to a second plurality of higher-order OAM modes and a first Gaussian mode, a second spatial light modulator configured to drop the first Gaussian mode and add a second Gaussian mode to the second plurality of higher-order OAM modes, and a third spatial light modulator configured to up-convert the second plurality of higher-order OAM modes and the second Gaussian mode to a third plurality of higher-order OAM modes for further communications.

In at least one aspect, a device for Orbital Angular Momentum (OAM) based optical communication includes a first spatial light modulator configured to down-convert a first plurality of higher-order OAM modes from a communication signal to a second plurality of higher-order OAM modes and a first Gaussian mode, a second spatial light modulator configured to drop the first Gaussian mode and add a second Gaussian mode to the second plurality of higher-order OAM modes, and a third spatial light modulator configured to up-convert the second plurality of higher-order OAM modes and the second Gaussian mode to a third plurality of higher-order OAM modes for further communications.

An optical line terminal (OLT) channel termination (CT) comprises a receiver configured to receive an upstream message which comprises a correlation tag from an optical network unit (ONU), wherein the correlation tag represents a unique number, a processor coupled to the receiver and configured to process the upstream message, and generate a downstream message based on the upstream message, wherein the downstream message comprises the correlation tag, and a transmitter coupled to the processor and configured to transmit the downstream message to the ONU.

An assembly of waveguide wavelength multiplexers and demultiplexers, together with continuous wave (CW) laser transmitters that interface to grating couplers on a silicon photonics chip, providing CW sources, multiplexed output and optionally multiplexed input, all using a single photonic lightwave circuit (PLC).

An apparatus comprising a frontend configured to convert an optical IM signal associated with a remote optical transmitter into a plurality of analog electrical signals, determine a plurality of DC offsets for the analog electrical signals, remove the DC offsets from the analog electrical signals to produce a plurality of DC-free analog signals, and convert the DC-free analog signals into a plurality of DC-free digital signals, and a DSP unit coupled to the frontend and configured to perform fiber dispersion compensation on the DC-free digital signals according to a dispersion value associated with the remote optical transmitter to produce a plurality of DC-free compensated digital signals, and add the DC offsets to the compensated digital signals to produce a plurality of DC-restored compensated digital signals.

A device may obtain first information related to a digital service that may identify a digital path. The digital path may include digital nodes and optical links, of an optical network, to provide the digital service. The device may determine second information based on the first information. The second information may describe a relationship between one or more digital services and one or more digital paths. The device may provide a graphical representation, via a user interface, of the one or more digital paths. The device may provide the second information in relation to the graphical representation. The device may detect a user interaction with the graphical representation. The user interaction may relate to one or more of the digital services and/or one or more of the digital paths. The device may cause the digital nodes and/or the optical links to be configured.

A system is provided for training a device design network. The system includes an interface configured to input data of a device, a memory to store the device design network including an encoder, a decoder, and an adversarial block, and a processor. The processor is, in connection with the memory, configured to update the encoder and the decoder based on a first loss function to reduce the difference between the input data and output data of the decoder, wherein the encoder is constructed by at least one convolutional layer followed by at least one parallel fully connected layer to extract features of a layout of the device, and update the adversarial block to construct by maximizing a second loss function.

A manner of managing data transmission and operating-mode transitions in a communication network. A network node having a transmitter and receiver is selectively transitioned into a Transmit state, where the Transmit state is a condition wherein the transmitter is turned on for data transmission only during timeslots provided for by a PBW (pre-allocation bandwidth) and remains off otherwise. The PBW and clock drift allowance permits the receiver to remain off during all or most of the Transmit state.