The systems, apparatuses and methods of the present invention set forth improvements to the problems of the current pairing or duplex paradigm, resulting in a dramatic increase in fiber transmission efficiency, accomplished explicitly by restructuring presently-aligned C-Band wavelengths into innovative DWDM transmit and receive formats, and through implementing photonic-wave changes, which directs Ethernet data flow onto new path adaptations. These improvements could reduce line haul expenses significantly, believed to reach a projected 50% less requirement/deployment of fiber strands. This saving would offer owner-operators substantial fiber strand cost reductions, affecting transportation rates of high-bandwidth digital payloads traversing over DWDM networks, and lower usage rates of cross-connections amid multiple equipment inter-exchanging throughout large data centers.

A system and method for efficient optical signal amplification with system monitoring features are provided. For example, an optical repeater may include two different 4-port thin-film gain flattening filters (TF-GFFs), which may be connected to provide a high-loss loop-back (HLLB) path in the optical repeater for system monitoring. The 4-port TF-GFF may have four different ports and may integrate the functionalities of a conventional GFF and a coupler into a single component, thereby increasing power efficiency of the optical repeater.

Proposed is an OLT for a passive optical wavelength division multiplex network. The network contains optical transmitters for generating downstream signals of an L-Band, as well as optical receivers for receiving upstream signals of a C-Band. Furthermore, the OLT contains a bi-directional SOA and an optical interface. The optical interface, the SOA, the transmitters and the receivers are optically coupled such that an upstream signal received at the optical interface is firstly provided to the bi-directional SOA and subsequently from the SOA to one of the receivers, and such that a downstream signal generated by one of the transmitters is firstly provided to the bi-directional SOA and then subsequently to the optical interface. The bi-directional SOA has a gain function that is not constant with respect to a wavelength of an optical signal to be amplified. Furthermore, the gain function is maximal for a wavelength located within the C-band.

In one embodiment, a switched amplifier is provided to amplify a data transmission. The switched amplifier may use a control signal that is received via a control signal channel in a transmission cable. Also, the switched amplifier may detect signal power to determine whether the data transmission is received at one of a first port and a second port. Data transmissions via the data transmission channel occur in a first direction and a second direction in a same frequency range in a time division multiplex (TDD) mode. Also, the control signal and data transmission are diverted from the transmission cable that transmits a type of signal different from the control signal and the data transmission. The switched amplifier is controlled based on the control signal or the signal power detected. The amplified signal is diverted in the first direction or the second direction via the data transmission channel back to the transmission cable.

The present invention relates to a method for optimizing performance of a multi-span optical fiber network. Each span has an associated optical transmission fiber connected to an associated optical amplifier. Gain and output power of the associated optical amplifier are respectively controlled independently. An amplifier noise figure respectively depends on the gain of the associated optical amplifier, with each associated optical amplifier further connected to launch optical signals into a remainder of a corresponding optical transmission line. The method includes the steps of for each span, computing the amplifier noise figure and a non-linear noise generated in the span based on information about the span and using the computed amplifier noise figure and the computed non-linear noise to compute an optimum launch power, and optimizing performance of the multi-span optical fiber network based on the computed optimum launch powers of all spans.

The present invention discloses an optical line terminal that includes one or more downstream signal processing means for generating a downstream signal, and converting data of the downstream signal into a serial data; a wavelength division multiplexing means for combining the serial data of different wavelengths together and then performing transmission of the combined signals; and one or more upstream signal processing means for extracting data of an upstream signal from the wavelength division multiplexing means. The terminal includes an extender including a first optical amplifier for amplifying the upstream signal, a second optical amplifier for amplifying the downstream signal, a Raman wavelength division multiplexing module for separating and combining data signal and pump light from Raman pump unit, and a Raman pump unit coupled to the Raman wavelength division multiplexing module to provide Raman amplification to the upstream and downstream signals.

An object is to respectively provide excitations light from a plurality of light sources to an odd number of fiber pairs. Optical amplifiers are disposed in three fiber pairs including two optical fibers through which optical signals are transmitted, respectively. The optical multiplexer/demultiplexer has inputs connected to light sources and three outputs. An optical multiplexer/demultiplexer has inputs connected to light sources and three outputs. In optical multiplexers/demultiplexers, one input is alternatively connected to any one of the three outputs of the optical multiplexer/demultiplexer, the other input is alternatively connected to any one of the three outputs of the optical multiplexer/demultiplexer, one output is alternatively connected to one optical fiber of any one of the three pairs, and the other output is alternatively connected to the other optical fiber of any one of the three pairs.

A bidirectional optical repeater having two unidirectional optical amplifiers and a supervisory optical circuit connected to optically couple the optical ports thereof. In an example embodiment, the supervisory optical circuit provides one or more pathways therethrough for supervisory optical signals, each of these pathways having located therein a respective narrow band-pass optical filter. The supervisory optical circuit further provides one or more pathways therethrough configured to bypass the corresponding narrow band-pass optical filters in a manner that enables backscattered light of any wavelength to cross into the optical path that has therein the unidirectional optical amplifier directionally aligned with the propagation direction of the backscattered light.

This disclosure describes C and L band optical communications module link extender, and related systems and methods. An example method may include receiving, by a first dense wave division multiplexer (DWDM) of an amplification module in communication with an optical communication module link extender (OCML), first passive optical network (PON) signals in a downstream direction. The example method may also include combining the first PON signals into a combined PON signal, and outputting the combined PON signal to the OCML. The example method may also include receiving, by a first input of the OCML, the combined PON signal. The example method may also include receiving by a second dense wave division multiplexer (DWDM) of the OCML, one or more optical data signals in the downstream direction, the one or more optical data signals being a different signal type than the one or more PON signals. The example method may also include combining, by the second DWDM, the one or more optical data signals into a combined optical data signal, and outputting the combined optical data signal. The example method may also include outputting, by the OCML, the combined optical data signal and the combined PON signal. The example method may also include receiving, from the amplification module and from the OCML, a second combined PON signal in an upstream direction at one or more Raman pumps of the amplification module. The example method may also include outputting, by the one or more Raman pumps, the second combined PON signal to the first DWDM.

A system and method for efficient optical signal amplification with system monitoring features are provided. For example, an optical repeater may include two different 4-port thin-film gain flattening filters (TF-GFFs), which may be connected to provide a high-loss loop-back (HLLB) path in the optical repeater for system monitoring. The 4-port TF-GFF may have four different ports and may integrate the functionalities of a conventional GFF and a coupler into a single component, thereby increasing power efficiency of the optical repeater.