Various implementations of a data communication cable assembly are disclosed that improve the transmission of data signals that traverse long distances. Some cable assembly implementations are configured to transmit data signals via one or more electrical wire mediums and one or more signal extenders that modify the data signals for improved transmission between devices over one or more electrical wire mediums. Other cable assembly implementations are configured to transmit data signals via one or more optical transmission mediums and optical-to-electrical and electrical-to-optical converters for improved transmission of the data signals between devices. Other cable assembly implementations are configured for cascading or daisy-chaining together for transmitting data signals between devices in the optical and/or electrical domain.

Methods and apparatus are provided for switching an optical signal. In one aspect, an optical switching apparatus comprises a first beam splitting apparatus configured to split a first optical input signal into first and second optical signals, wherein the first optical signal has substantially the same polarization state as the second optical signal. The apparatus also comprises a switching matrix comprising a plurality of first outputs of the switching matrix and a plurality of second outputs of the switching matrix, each first output of the switching matrix associated with a respective one of the second outputs of the switching matrix, the switching matrix configured to selectively direct the first optical signal to a selected one of the first outputs of the switching matrix and to selectively direct the second optical signal to the second output of the switching matrix associated with the selected first output of the switching matrix. The apparatus further comprises a plurality of beam combining apparatus, each beam combining apparatus configured to combine optical signals from a respective one of the first outputs of the switching matrix and its associated second output of the switching matrix.

A wavelength division multiplexing filter comprises: a first multi-order Mach-Zehnder interferometer comprising a plurality of first-order Mach-Zehnder interferometers, and a second multi-order Mach-Zehnder interferometer comprising a plurality of first-order Mach-Zehnder interferometers; wherein the first multi-order Mach-Zehnder interferometer and the second multi-order Mach-Zehnder interferometer are included in a group of multiple multi-order Mach-Zehnder interferometers arranged within a binary tree arrangement, the binary tree arrangement comprising: a first set of a plurality of multi-order Mach-Zehnder interferometers, the first set including the first multi-order Mach-Zehnder interferometer, and having an associated spectral response with a first spacing between adjacent passbands, and a second set of at least twice as many multi-order Mach-Zehnder interferometers as in the first set, the second set including the second multi-order Mach-Zehnder interferometer, and having an associated spectral response with a second spacing between adjacent passbands that is twice the first spacing.

A TORminator module is disposed with a switch linecard of a rack. The TORminator module receives downlink electrical data signals from a rack switch. The TORminator module translates the downlink electrical data signals into downlink optical data signals. The TORminator module transmits multiple subsets of the downlink optical data signals through optical fibers to respective SmartDistributor modules disposed in respective racks. Each SmartDistributor module receives multiple downlink optical data signals through a single optical fiber from the TORminator module. The SmartDistributor module demultiplexes the multiple downlink optical data signals and distributes them to respective servers. The SmartDistributor module receives multiple uplink optical data signals from multiple servers and multiplexes them onto a single optical fiber for transmission to the TORminator module. The TORminator module coverts the multiple uplink optical data signals to multiple uplink electrical data signals, and transmits the multiple uplink electrical data signals to the rack switch.

A node (10) includes multiplexing unit (11) that multiplexes a plurality of subcarrier signals for performing optical wavelength multiplexing communication into a wavelength group signal; output unit (12) that outputs the multiplexed wavelength group signal to an optical transmission line; pre-multiplexing level correction unit (13) that corrects a level deviation between the subcarrier signals before the multiplexing based on an optical level of the wavelength group signal in the output unit (12); and post-multiplexing level correction unit (14) that corrects a level deviation of the wavelength group signal after the multiplexing including the corrected subcarrier signals based on the optical level of the wavelength group signal in the output unit (12).

A TORminator module is disposed with a switch linecard of a rack. The TORminator module receives downlink electrical data signals from a rack switch. The TORminator module translates the downlink electrical data signals into downlink optical data signals. The TORminator module transmits multiple subsets of the downlink optical data signals through optical fibers to respective SmartDistributor modules disposed in respective racks. Each SmartDistributor module receives multiple downlink optical data signals through a single optical fiber from the TORminator module. The SmartDistributor module demultiplexes the multiple downlink optical data signals and distributes them to respective servers. The SmartDistributor module receives multiple uplink optical data signals from multiple servers and multiplexes them onto a single optical fiber for transmission to the TORminator module. The TORminator module coverts the multiple uplink optical data signals to multiple uplink electrical data signals, and transmits the multiple uplink electrical data signals to the rack switch.

A cyclic wavelength band permutation device (31) includes as many wavelength band converters (32a to 32c) as the wavelength bands of optical signals (S1, C1, and L1), and the wavelength band converters are individually connected to the output terminals of corresponding optical amplifiers among a plurality of optical amplifiers (17a to 17c) connected to an optical fiber (16) in an inserted manner. When a wavelength-multiplexed signal beam obtained by multiplexing optical signals in different wavelength bands is multiband-transmitted through an optical fiber while being amplified by the plurality of optical amplifiers, each wavelength band converter performs a cyclic permutation process of transitioning or converting an optical signal allocated to the shorter wavelength band side in the bands of the optical fiber to the longer wavelength band side, and also transitioning or converting an optical signal allocated to the longest wavelength band to the shortest wavelength band.

An integrated transmitter chip comprising: at least one input port disposed at a first end of the integrated transmitter chip; a first variable power divider optically connected to each input port of the at least one input port; a second and a third variable power dividers optically branched from each first variable power divider; a first and a second optical channel optically branched from the second variable power divider, a third and a fourth optical channel optically branched from the third variable power divider; and at least one WDM optically attached to corresponding optical channels and configured to selectively modify the polarization of and multiplex corresponding optical signals into a output optical signal, wherein a laser beam is launched into an input port, split by corresponding variable power dividers based upon each dividers corresponding splitting ratio, then multiplexed and combined into an output optical signal having dual polarization modes.

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.

The present disclosure relates to an optical fiber access system based on passive optical networks. In particular the present disclosure relates to a PON system with increased capacity and a method for increasing the capacity in a PON system. One embodiment relates to an optical line terminal for a passive optical network, comprising at least one transmitter for generating a time division multiplexed (TDM) downstream optical data signal, a first time lens optical signal processor configured to convert the downstream TDM signal to a downstream WDM signal for distribution to a plurality of users, and at least one receiver for receiving and processing an upstream signal from said users.