A transmission device including a demultiplexer configured to demultiplex a multiplexed light obtained by multiplexing the plurality of wavelength division multiplexing (WDM) optical signals including different wavelength bands into the plurality of WDM optical signals, a plurality of optical amplifiers configured to amplify the plurality of WDM optical signals, respectively, a wavelength converter configured to convert a first wavelength band of the wavelength bands of at least a first WDM optical signal of the plurality of WDM optical signals amplified by the plurality of optical amplifiers into a second wavelength band of the wavelength bands of a second WDM optical signal of the plurality of WDM optical signals so that the second wavelength band does not overlap among the wavelength bands, and a multiplexer configured to multiplex the plurality of WDM optical signals which include the wavelength bands converted by the wavelength converter.

A transmission apparatus includes a first multiplexer configured to multiplex light of wavelengths of a first wavelength band to output first wavelength multiplex light, a first wavelength converter configured to convert the first wavelength multiplex light into wavelengths of a second wavelength band which is different from the first wavelength band, by using first excitation light, a second multiplexer configured to multiplex light of wavelengths of the first wavelength band which are different from the wavelengths of the first wavelength multiplex light to output second wavelength multiplex light, a second wavelength converter configured to convert the second wavelength multiplex light into wavelengths of the second wavelength band, by using second excitation light, a third multiplexer configured to multiplex the first wavelength multiplex light converted into the wavelengths of the second wavelength band, and the second wavelength multiplex light converted into the wavelengths of the second wavelength band.

The present disclosure provides a wavelength division multiplexing (WDM) device for demultiplexing an optical signal including a plurality of wavelength channels. The device comprises at least one demultiplexer block configured to provide, for each wavelength channel of the optical signal, two half-channel signals. The device further comprises a mode mapping block configured to map one half-channel signal related to a split wavelength channel into a first polarization mode, and the other half-channel signal related to the same split wavelength channel into a second polarization mode. The device also comprises an output block for each wavelength channel, each output block being configured to combine polarized half-channel signals related to the same wavelength channel.

An electromagnetic signal transport and distribution system simultaneously transports over one single mode fiber various programming specifically requested by multiple users in multiple locations while simultaneously offering bidirectional communications with a public network.

Methods, systems, and apparatus for hosting an optical line terminal (OLT) bonding engine are disclosed. In one aspect, packet data for transmission over a passive optical (PON) is selected. A transmission wavelength assigned to the packet data is identified. A particular OLT is selected from among the additional OLTs to transmit the packet data over the PON based on the corresponding wavelength of the particular OLT matching the identified transmission wavelength assigned to the packet. The packet data is formatted based on the particular OLT. The formatted packet data is transmitted to the particular OLT for transmission over the communications interface.

An optical network element includes an optical multiplexing/demultiplexing device forming a degree; a channel holder source connected to the optical multiplexing/demultiplexing device; and a controller configured to, responsive to provisioning a media channel on the degree, wherein the media channel is a contiguous portion of optical spectrum supporting N channels, N>1, cause allocation of optical filter bandwidth in the optical multiplexing/demultiplexing device for M channels in the media channel, M<N, cause provisioning of the M channels in the media channel, and cause configuration of NM channel holders in the media channel from the channel holder source.

Methods, systems, and apparatus for hosting an optical line terminal (OLT) bonding engine are disclosed. In one aspect, packet data for transmission over a passive optical (PON) is selected. A transmission wavelength assigned to the packet data is identified. A particular OLT is selected from among the additional OLTs to transmit the packet data over the PON based on the corresponding wavelength of the particular OLT matching the identified transmission wavelength assigned to the packet. The packet data is formatted based on the particular OLT. The formatted packet data is transmitted to the particular OLT for transmission over the communications interface.

In an example, a communication module includes an optical transmitter, an optical receiver, and a periodical filter. The optical transmitter is configured to emit an outbound optical signal. The optical receiver is configured to receive an inbound optical signal. A first frequency of the outbound optical signal is offset from a second frequency of the inbound optical signal by an amount less than a channel spacing of a multiplexer/demultiplexer implemented in an optical communication system that includes the communication module. The periodical filter is positioned in optical paths of both the outbound optical signal and the inbound optical signal and has a transmission spectrum with periodic transmission peaks and troughs. The first frequency of the outbound optical signal may be aligned to one of the transmission peaks and the second frequency of the inbound optical signal may be aligned to one of the transmission troughs, or vice versa.

A method and apparatus for transporting data through a single optical fiber (SOF) the method comprising the steps of providing (S1) transmission Tx, wavelength division multiplexed, WDM, data channels and reception Rx, wavelength division multiplexed, WDM, data channels having the same frequency grid with frequency gaps between the WDM data channels; frequency shifting (S2) the Tx-WDM data channels and/or the Rx-WDM data channels to avoid spectral overlap between the Tx-WDM data channels and the Rx-WDM data channels; combining (S3) the frequency shifted Tx-WDM data channels and the frequency shifted Rx-WDM data channels; and transporting (S4) data via the combined WDM data channels through said single optical fiber (SOF) in opposite directions.

The present disclosure provides a WDM, device 100 for demultiplexing an optical signal 101 including a plurality of N wavelength channels. The device 100 comprises at least one demultiplexer block 102 configured to split the optical signal into two half-channel signals 103 for each wavelength channel. The device 100 further comprises a mode mapping block 104 configured to map one half-channel signal 103 related to a split wavelength channel into a first polarization mode, and the other half-channel signal 103 related to the same split wavelength channel into a second polarization mode. The device 100 also comprises an output block 105 for each wavelength channel, which is configured to combine all polarized half-channel signals related to the same wavelength channel.