An Optical Protection Switch (OPS) includes a splitter connected to a transmitted input and a path continuity monitor transmitter and configured to output the transmitted input with a path continuity monitor signal to two paths; a switch connected to a receiver output and configured to provide one of two receiver inputs each from one of the two paths based on a setting of the switch; and one or more path continuity monitor receivers connected to the two receiver inputs and configured to detect a corresponding path continuity monitor signal from a complementary OPS, wherein the setting of the switch is set based upon the received path continuity monitor signals. The one or more path continuity monitor receivers each have a narrow optical bandwidth relative to an overall optical bandwidth of the transmitted input.

A system and method for performing an in-service optical time domain reflectometry test, an in-service insertion loss test, and an in-service optical frequency domain reflectometry test using a same wavelength as the network communications for point-to-point or point-to-multipoint optical fiber networks while maintaining continuity of network communications are disclosed.

A method for reconfiguring a message encoding parameter used by a first channel node to transmit information to a second channel node via a first optical channel in an optical network comprises the steps of sending, via a second optical channel of the optical network, a reconfiguration request with a message encoding parameter from the first channel node to the second channel node of the first optical channel; receiving, via the second optical channel, a reply to the reconfiguration request from the second channel node; and modifying the first channel node in accordance with the message encoding parameter used to transmit information from the first channel node to the second channel node based on the reply.

An optical signal is transmitted between first and second transmission devices. When a network control device receives a shutdown report that indicates a loss of light from both of the first and second transmission devices, the network control device transmits a first instruction to resume a transmission of a control signal to both of the first and second transmission devices. When the network control device receives a detection report that indicates a reception of the control signal from both of the first and second transmission devices, the network control device transmits a second instruction to resume a transmission of a WDM signal to both of the first and second transmission devices.

An optical device having an amplifier and a controller is described. The amplifier is configured to amplify an optical signal in at least one of the C-Band or the L-Band. The controller includes a processor and a non-transitory computer readable medium. The non-transitory computer readable medium storing computer executable code that when executed by the processor causes the processor to: select a target tilt and gain setting from a plurality of target tilt and gain settings stored in the non-transitory computer readable medium based on the type of fault event message responsive to a fault event message affecting the C-band or the L-Band. The selected and pre-calculated target tilt and gain settings are applied to the amplifier.

This application discloses an optical amplifier apparatus including a first amplifier unit and a hybrid filter unit. The first amplifier unit is configured to receive a first beam including signal light and first monitoring light. The first amplifier unit is further configured to amplify the first beam to obtain a second beam. The hybrid filter unit is configured to: receive the second beam output by the first amplifier unit, and separate the first monitoring light and the signal light from the second beam. The hybrid filter unit is further configured to: transmit the first monitoring light in the second beam to a monitoring light detection apparatus of a first station through a first output port. The hybrid filter unit is further configured to: perform gain flattening filtering processing on the signal light in the second beam to obtain filtered signal light, and output the filtered signal light.

The disclosure is directed to an optical telecommunications system which includes a central node and a plurality of user nodes. The central node provides the light necessary to enable communication between the user nodes. Within the central node is a multi-wavelength source, providing lights at different wavelengths, along with a wavelength selector. The wavelength selector selects one of the lights at different wavelengths from the multi-wavelength source for delivery to the user nodes such that the user nodes then modulate this light for transmission between nodes.

An apparatus includes a reconfigurable optical add/drop multiplexer (ROADM) having an input port to receive a first optical signal from a second device. The ROADM also includes a first wavelength selective switch (WSS), in optical communication with the input port, to convert the first optical signal into a second optical signal, a loopback, in optical communication with the first WSS, to transmit the second optical signal, and a second WSS, in optical communication with the loopback, to convert the second optical signal to a third optical signal and direct the third optical signal back to the second device via the input port.

A system and method for performing an in-service optical time domain reflectometry test, an in-service insertion loss test, and an in-service optical frequency domain reflectometry test using a same wavelength as the network communications for point-to-point or point-to-multipoint optical fiber networks while maintaining continuity of network communications are disclosed.

An optical transmission apparatus includes a splitter configured to split a first wavelength division multiplexed optical signal arranged in a first wavelength band and a second wavelength division multiplexed optical signal arranged in a second wavelength band, respectively, from an optical signal including the first wavelength division multiplexed optical signal and the second wavelength division multiplexed optical signal, a wavelength converter configured to convert a wavelength of the split second wavelength division multiplexed optical signal to generate a third wavelength division multiplexed optical signal to be arranged in the first wavelength band, an optical monitor configured to monitor power of each wavelength channel of the third wavelength division multiplexed optical signal, and a transmitter configured to transmit a monitoring result by the optical monitor to a transmission source node of the optical signal or a relay node of the optical signal.