An optical communication system of the present invention switches a communication wavelength from a current communication wavelength to a auxiliary communication wavelength when an abnormality occurs in a communication wavelength between a station-side device and any one of a plurality of subscriber devices. Further, this optical communication system switches a communication wavelength used for communication between the subscriber device and the station-side device that perform communication using the auxiliary communication wavelength from the auxiliary communication wavelength back to the current communication wavelength when communication is recovered from an abnormality in the current communication wavelength.

A carrier office includes an optical line terminal, a first transmit-erbium-doped fiber amplifier (EDFA), and a second transmit-EDFA. The OLT is configured to transmit first and second optical signals. The first transmit-EDFA is optically coupled to the OLT and a first feeder fiber, and the first feeder fiber is optically coupled to a first remote node (RN). The first transmit-EDFA is operable between a respective enabled state and a respective disabled state. The second transmit-EDFA is optically coupled to the OLT and a second feeder fiber, and the second feeder fiber is optically coupled to a second RN. The second transmit-EDFA is operable between a respective enabled state and a respective disabled state.

A method of Noisy Window and associated management messages to support set splitting if activating ONUs with uncalibrated transmitter, offering a power grant for unmodulated upstream transmission, measuring the average received optical power in all upstream wavelength channels and providing downstream indication of the upstream wavelength channel with abnormally high average received power.

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 coaxial transmitter optical subassembly (TOSA) including a cuboid type TO laser package may be used in an optical transceiver for transmitting an optical signal at a channel wavelength. The cuboid type TO laser package is made of a thermally conductive material and has substantially flat outer surfaces that may be thermally coupled to substantially flat outer surfaces on a transceiver housing and/or on other cuboid type TO laser packages. An optical transceiver may include multiple coaxial TOSAs with the cuboid type TO laser packages stacked in the transceiver housing. The cuboid type TO laser package may thus provide improved thermal characteristics and a reduced size within the optical transceiver.

Various embodiments relate to bi-directional optical communication. An optical system may include a first transceiver module including at least one transmitter and at least one receiver, wherein each transmitter of the at least one transmitter is configured to transmit a first signal via an optical fiber and at a wavelength. The optical system may further include a second transceiver module configured to communicate with the first transceiver module via the optical fiber and including at least one transmitter and at least one receiver, wherein each transmitter of the at least one transmitter of the second transceiver module is configured to transmit a second signal via the optical fiber and at another, different wavelength.

This application provides a wavelength negotiation method of a multi-wavelength passive optical network, including: receiving a wavelength status table that is broadcast by an OLT over each downstream wavelength channel of a multi-wavelength PON system, where the wavelength status table is used to indicate information about available wavelengths of the multi-wavelength PON system and statistic information of registered ONUs of a corresponding wavelength channel; selecting an upstream transmit wavelength and a downstream receive wavelength according to the wavelength status table; and reporting information about the upstream transmit wavelength and information about the downstream receive wavelength to the OLT so that the OLT refreshes the wavelength status table. This application also provides a wavelength negotiation apparatus of the multi-wavelength passive optical network and a multi-wavelength passive optical network system.

A method of configuring transmission wavelengths in a passive optical network comprising a wavelength selective routing element between first and second locations. The method comprises: at a first location: a. iteratively generating and transmitting a first optical signal at different ones of a plurality of wavelengths until a second optical signal is received at the first location; and then b. ceasing transmission of the first optical signal and then recommencing transmission of the first optical signal at the wavelength being transmitted when the second optical signal was received; and at a second location, remote from the first location: c. waiting until the first optical signal is received at the second location; d. iteratively generating and transmitting the second optical signal at different ones of a plurality of wavelengths until the first optical signal is no longer received at the second location; and e. maintaining generation and transmission of the second optical signal at the wavelength being transmitted when the first optical signal was no longer received.

An optical line terminal for use in a multi-wavelength network to operatively connect via a PON port by a first connection to a first network node and to operatively connect via the PON port by a second connection to a second network node, the optical line terminal being configured to operate under first network conditions by sending no data via the second connection, and to operate under second network conditions by sending data via the second connection.

A system includes an optical fiber cross-connect module with upstream ports and downstream ports, a first set of optical fibers connected from optical line terminals to the upstream ports, and a second set of optical fibers connected to the downstream ports and a customer optical network unit. The optical line terminals provide multiple wavelengths carrying optical signals at different bitrates over the first set of optical fibers. The customer optical network unit includes a tunable filter configured to receive any one of the multiple wavelengths. The optical fiber cross-connect module divides the optical signals received at each of the upstream ports into each of the downstream ports, and the customer optical network unit may be tuned to pass through a particular wavelength from the multiple wavelengths.