In order to solve the problems described above, an object of the present invention is to provide an optical communication system and a control method that automatically adjust a branching ratio of an optical splitter in accordance with a connection of a new ONU. An optical communication system according to the present invention causes an operation system or a DBA (Dynamic Bandwidth Allocation) function and a determining unit of a branching ratio of an optical splitter to cooperate with each other, adjusts the branching ratio so as to enable ranging with an active ONU, and takes into consideration an initial connection sequence through which an ONU is newly connected.

This application provides a port detection method and apparatus. In the technical solutions in this application, an OLT or an ONU may determine, based on at least two wavelengths and a preset correspondence, port information that is of an optical splitter and that corresponds to the ONU. That is, a branch port directly or indirectly connected to the ONU is defined by using the at least two wavelengths. In this way, different branch ports can be distinguished by using combinations of a plurality of wavelengths, to define a large quantity of branch ports of the optical splitter by using free combinations of a small quantity of wavelengths.

First transmission device includes a first counter that generates counter value incremented in a specified cycle. Second transmission device includes a second counter that. generates counter value incremented in the specified cycle. Polarization variation monitoring device acquires a first counter value generated by the first counter and a second counter value extracted by the first transmission device from a received frame transmitted from the second transmission device when the first transmission device detects polarization variation, and a third counter value generated by the second counter and a fourth counter value extracted by the second transmission device from a frame transmitted from the first transmission. device when the second detector detects the polarization variation. The polarization variation monitoring device determines an occurrence position of the polarization variation based on the first counter value, the second counter value, the third counter value and the fourth counter value.

Example polarization processing optical devices, methods, and systems are disclosed. A polarization processing optical device includes a polarization beam splitter (PBS), a polarization rotator (PR), a coupler, and a phase tuner (PT), where one port of the PBS is configured to input a continuous light source, and the other two ports of the PBS are respectively connected to the PR and one port of the coupler, the PR is connected to another port of the coupler, the PT is disposed on a connection between the PBS and the coupler or a connection between the PR and the coupler, at least one port of the coupler is configured to output single-polarization light, and the PT is configured to control output optical power of the coupler.

The present disclosure relates to a digital filter arrangement (DFA) for compensating group velocity dispersion (GVD) in an optical transmission system (OTS) wherein the DFA is configured to receive a sequence of samples of a digital input signal in the time domain in the form of consecutive blocks of size L. The DFA is configured to generate M discrete Fourier transforms of a current overlap block of a size N greater than the size L and of M−1 delayed versions of the current overlap block. The DFA is configured to filter the entries of the generated M discrete Fourier transforms to generate an output discrete Fourier transform with N entries, wherein the compensation filter is implemented by a delay network and a linear combination algorithm.

Deep neural networks (DNNs) have become very popular in many areas, especially classification and prediction. However, as the number of neurons in the DNN increases to solve more complex problems, the DNN becomes limited by the latency and power consumption of existing hardware. A scalable, ultra-low latency photonic tensor processor can compute DNN layer outputs in a single shot. The processor includes free-space optics that perform passive optical copying and distribution of an input vector and integrated optoelectronics that implement passive weighting and the nonlinearity. An example of this processor classified the MNIST handwritten digit dataset (with an accuracy of 94%, which is close to the 96% ground truth accuracy). The processor can be scaled to perform near-exascale computing before hitting its fundamental throughput limit, which is set by the maximum optical bandwidth before significant loss of classification accuracy (determined experimentally).

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.

Coherent optical multiplexing 1+1 protection disclosed herein uses multiplexers, each having multiplexing and demultiplexing sub-units. Relay ports of a node are connected with the multiplexers, and each relay port is configured to input and output optical signals with the corresponding multiplexer. Two transmission ports of the node are connected with disjoint paths and are configured to input and output optical signals therewith. The node includes: a first optical splitter having input ports connected with the relay ports and two output ports connected with the two transmission ports; an optical switch connected with the transmission ports respectively via two input interfaces; a second optical splitter, which is a 1×N optical splitter, having one input port connected with an output interface of the optical switch and having output ports connected with the relay ports. The solution is reliable in implementation, has low insertion loss, and has good transmission performance.

A method at a receiver comprises receiving a signal conveying symbols at respective positions within a clock cycle, the symbols comprising a data set consisting of data symbols and a pilot set consisting of pilot symbols; determining detected phases of the symbols based on the signal; generating first phase estimates based on the detected phases of a subset of the pilot set, and reference phases of the subset of the pilot set, the first phase estimates being associated with the positions of the pilot set; and generating second phase estimates based on the detected phases of the pilot set, reference phases of the pilot set, and the first phase estimates, the second phase estimates being associated with the positions of the pilot set and of at least a subset of the data set; and applying rotations to the detected phases of the symbols based on the second phase estimates.

A method is provided for assessing the quality of an optical transmitter and/or its interoperability with a receiver. The method includes obtaining an optical signal output by an optical transmitter and performing coherent optical-to-electrical detection of the optical signal to produce an in-phase receive signal and a quadrature receive signal. The method further includes a computing device emulating a worst-case configuration of an optical fiber with which the optical transmitter is to be used, based on the in-phase receive signal and the quadrature receive signal to produce a noise contribution associated with the worst-case characteristics of the optical fiber and determining a figure of merit of the optical transmitter based on the noise contribution.