To provide a light wavelength separation device and a light wavelength separation method that can be flexibly adapted for various channel intervals of a wavelength-division multiplexed (WDM) signal, a light wavelength separation circuit is provided with: an optical coupler which splits a wavelength-multiplexed optical signal in which optical signals of a plurality of channels are multiplexed; a band-pass filter which is arranged for each of output ports of the optical coupler, separates optical signals included in the wavelength-multiplexed optical signal inputted from the output ports of the optical coupler into channels of which the central frequencies are not adjacent to each other, and outputs the separated optical signals from respectively different output ports; and an optical switch which selects one of paths of the optical signals inputted from the output ports of each band-pass filter.

Fabrication-tolerant on-chip multiplexers and demultiplexers are provides via a lattice filter interleaver configured to receive an input signal including a plurality of individual signals and to produce a first interleaved signal with a first subset of the plurality of individual signals and a second interleaved signal with a second subset of the plurality of individual signals; a first Bragg interleaver configured to receive the first interleaved signal and produce a first output signal including a first individual signal of the plurality of individual signals and a second output signal including a second individual signal of the plurality of individual signals; and a second Bragg interleaver configured to receive the second interleaved signal and produce a third output signal including a third individual signal of the plurality of individual signals and a fourth output signal including a fourth individual signal of the plurality of individual signals.

Systems and methods for alien wavelength management. One embodiment is an apparatus for managing alien wavelengths for a Wavelength Division Multiplexing (WDM) system. The apparatus includes memory to store signal thresholds for alien wavelength signals transmitting over the WDM system, wherein the alien wavelength signals are generated by third-party equipment independently controlled from the WDM system. The apparatus also includes an Alien Wavelength Control Unit (AWCU) coupled between the third-party equipment and a channelization port of the WDM system, the AWCU configured to measure a signal parameter of an alien wavelength signal transmitted by the third-party equipment to the channelization port. The apparatus further includes a controller coupled with the AWCU and configured, in response to determining that the signal parameter is outside a signal threshold of the WDM system, to direct the AWCU to modify the alien wavelength signal to protect the WDM system.

A bidirectional optical device includes a first optical component, wherein a portion of a first interface of the first optical component has a reflector coating, wherein a second interface of the first optical component has an optical coating, and wherein the first optical component includes an internal splitting interface disposed between the first interface and the second interface, and a second optical component including a reflector aligned to the second interface of the first optical component, wherein the first optical component and the second optical component comprise an unbalanced Mach-Zehnder (MZ) interferometer.

Systems and methods for alien wavelength management. One embodiment is an apparatus for managing alien wavelengths for a Wavelength Division Multiplexing (WDM) system. The apparatus includes memory to store signal thresholds for alien wavelength signals transmitting over the WDM system, wherein the alien wavelength signals are generated by third-party equipment independently controlled from the WDM system. The apparatus also includes an Alien Wavelength Control Unit (AWCU) coupled between the third-party equipment and a channelization port of the WDM system, the AWCU configured to measure a signal parameter of an alien wavelength signal transmitted by the third-party equipment to the channelization port. The apparatus further includes a controller coupled with the AWCU and configured, in response to determining that the signal parameter is outside a signal threshold of the WDM system, to direct the AWCU to modify the alien wavelength signal to protect the WDM system.

Wavelength division multiplexers for space division multiplexing can include wavelength division multiplexing fanout devices or pump-signal combiners for multicore fibers.

An optical transceiver may include an optical transmitter and an optical receiver. The optical transmitter and receiver may each include a grid including one or more lanes spaced apart. Each lane may correspond to a predetermined optical signal, or wavelength. The optical transmitter may include one or more sets of lasers to output one or more optical signals corresponding to the grid. Each set of laser may output a set of optical signals. Each set of lasers and, therefore, each set of optical signals may have a different passband. For example, the multiplexing and/or demultiplexing architecture may have a wide passband for the first set of optical signals and a narrow passband for the second set of optical signals. The narrow passband may be determined based on the space between two wider passbands.

Provided are wavelength switching and configuration methods and devices for a Passive Optical Network (PON). The switching method includes the following operations. An Optical Network Unit (ONU) responds to a ranging request message sent by an Optical Line Terminal (OLT) on a first uplink wavelength supported by the ONU. The ONU receives ranging information sent by the OLT. The ONU uses the received ranging information as ranging information about a second uplink wavelength of the ONU, and performs data transmission on the second uplink wavelength according to a bandwidth allocation from the OLT. A path transmission time difference caused by a wavelength interval between the first uplink wavelength and the second uplink wavelength is less than a corresponding fault tolerance range when the OLT receives data. The ranging information is obtained by the OLT according to a ranging response sent by the ONU on the first uplink wavelength.

An optical transceiver may include an optical transmitter and an optical receiver. The optical transmitter and receiver may each include a grid including one or more lanes spaced apart. Each lane may correspond to a predetermined optical signal, or wavelength. The optical transmitter may include one or more sets of lasers to output one or more optical signals corresponding to the grid. Each set of laser may output a set of optical signals. Each set of lasers and, therefore, each set of optical signals may have a different passband. For example, the multiplexing and/or demultiplexing architecture may have a wide passband for the first set of optical signals and a narrow passband for the second set of optical signals. The narrow passband may be determined based on the space between two wider passbands.

Systems and methods for data transport, including submarine reconfigurable optical add/drop multiplexers, branching units configured to receive signals from trunk terminals (TTs), and dummy light filters configured to pass useful signals through the filters, and to reflect dummy light. Optical interleavers are configured to separate useful signals into two or more groups of optical channels, and the optical channels are set to a frequency of either a left or a right portion of a total channel bandwidth. De-interleavers merge signal groups together from trunk terminals, and lasers at each of the transponders at the source terminals are configured to adjust a destination of a channel by fine tuning a frequency or wavelength of the one or more signals.