Provided is a wavelength path communication node device with no collision of wavelengths and routes, capable of outputting arbitrary wavelengths, and capable of outputting them to arbitrary routes. An add/drop multiplexer (11) includes a communication unit (101) that communicates an optical signal with at least one client device and at least one network and a control unit (102) that indicates a transfer destination of the optical signal according to an attribute of the received optical signal to the communication unit (101). The control unit (102) indicates an attenuation amount of the optical signal to the communication unit (101) for each connected device. When a connected device is changed, the control unit (102) instructs the communication unit (101) to change the attenuation amount. The communication unit (101) attenuates the optical signal with the attenuation amount indicated by the control unit (102) and transfers the attenuated optical signal to a transfer destination.

A coherent passive optical network includes a downstream transceiver and first and second upstream transceivers in communication with an optical transport medium. The downstream transceiver includes a downstream processor for mapping a downstream data stream to a plurality of sub-bands, and a downstream transmitter for transmitting a downstream optical signal modulated with the plurality of sub-bands. The first upstream transceiver includes a first local oscillator (LO) for tuning a first LO center frequency to a first sub-band of the plurality of sub-bands, and a first downstream receiver for coherently detecting the downstream optical signal within the first sub-band. The second upstream transceiver includes a second downstream receiver configured for coherently detecting the downstream optical signal within a second sub-band of the plurality of sub-bands. The downstream processor dynamically allocates the first and second sub-bands to the first and second transceivers in the time and frequency domains.

Techniques for unified optical network unit power management in a passive optical network include operating an optical network unit (ONU) in a first state in which a transmitter of the ONU is turned off and a receiver of the ONU is turned on, operating the ONU in a second state in which both the transmitter and the receiver are turned off, and transitioning the ONU directly between the first state and the second state, based on a power management rule.

Disclosed herein are methods, structures, and devices for optical communications systems operating through turbulent media. More specifically, a spatial division multiplexing photonic integrated circuit is used in conjunction with digital signal processing systems to mitigate the effects of the turbulent media.

Disclosed herein are methods, structures, and devices for optical communications systems operating through turbulent media. More specifically, a spatial division multiplexing photonic integrated circuit is used in conjunction with digital signal processing systems to mitigate the effects of the turbulent media.

This disclosure describes a wavelength division multiplexing passive optical network system (100) comprising an optical line terminal (180) for controlling transmission of data that are carried by optical signals across the optical network system along an upstream or downstream path; a signal modulating loop circuit including a circulator (110) connected to the optical line terminal (180) for determining the transmission paths of the optical signals; a splitter (120) connected to the circulator (110) for splitting the optical signals into a first portion of optical signals and a second portion of optical signals according to a predetermined ratio; an amplifier (160) connected to the splitter (120) for amplifying the second portion of optical signals; and a modulator (170) connected in between the amplifier (160) and the splitter (120) for modulating the amplified second portion of optical signals to be transmitted to the circulator (110); a converter (140) connected to the splitter (130) for converting the first portion of optical signals into electrical signals; and one or more optical network units (150) connected in between the converter (140) and modulator (170) for receiving the electrical signals from the converter (140), and transmitting electrical signals to the modulator (170) for converting the electrical signals into optical signals to be transmitted together with the amplified second portion of optical signals to the optical line terminal (180); wherein the circulator (110) directs the optical signals received from the modulator (170) to the splitter (120) for being transmitted back into the signal modulating loop circuit and/or towards the optical network units along the downstream path, or towards the optical line terminal along the upstream path.

An optical buffer and a method for storing an optical signal using the optical buffer, where the optical buffer includes a first waveguide, a first optical delay waveguide loop and a controller. The first waveguide includes a first arm and a second arm, where a first end of the first arm is an input end of the optical buffer, and a second end of the second arm is an output end of the optical buffer. A second end of the first arm connects to a first end of the second arm. The first optical delay waveguide loop connects to the first arm at a first end using a first optical switch, and a second part of the first optical delay waveguide loop connects to the second arm at a second end using a second optical switch. The controller connects to the first optical switch and the second optical switch respectively.

An apparatus comprising a signal generator configured to produce a modulation signal, a filter coupled to the signal generator and configured to filter the modulation signal to produce a cancellation signal, and a reflective semiconductor optical amplifier (RSOA) coupled to the signal generator and the filter, wherein the RSOA is configured to generate an optical signal according to a difference between the modulation signal and the cancellation signal and transmit the optical signal towards a partial reflection mirror (PRM).

A system for delivering multiple passive optical network services is disclosed. The system includes a first optical transmission service comprising a common wavelength pair routed from a source to each of a plurality of subscribers. The system further includes a second optical transmission service comprising a plurality of unique wavelength pairs, where each of the unique wavelength pairs is routed from the source to a subscriber among the plurality of subscribers. The system delivers the first optical transmission service and the second optical transmission service to the subscriber on a single optical fiber.

A system for delivering multiple passive optical network services is disclosed. The system includes a first optical transmission service comprising a common wavelength pair routed from a source to each of a plurality of subscribers. The system further includes a second optical transmission service comprising a plurality of unique wavelength pairs, where each of the unique wavelength pairs is routed from the source to a subscriber among the plurality of subscribers. The system delivers the first optical transmission service and the second optical transmission service to the subscriber on a single optical fiber.