Abstract: A colorless mux/demux cable assembly, including a first fiber optic cable, a second fiber optic cable, and a main body that includes an N:1 optical combiner and a 1:N optical splitter. The N:1 optical combiner is configured to combine individual optical signals received by each of N input fibers of the second fiber optic cable and provide a combined output signal to an output fiber of the first fiber optic cable. The 1:N optical splitter is configured to split a combined input optical signal (having N wavelength channels) received via an input fiber of the first fiber optic cable and provide a split output signal comprising each of the N wavelength channels to each of N output fibers of the second fiber optic cable.

Abstract: The present disclosure describes a network including two levels of switching: a first level including wavelength selective switching via a first type of switching module, and a second level including fiber level switching via a second type of switching module. The two levels of switching allow for maintaining wavelength selective switching between transmission directions while introducing fiber selective switching between network degrees of the same transmission direction. The first type of switching module is configured to transmit and receive optical signals having a first set of wavelengths at a first network degree at a first direction in a node of a network. The second type of switching module is configured to transmit and receive the optical signals from the first type of switching module and route the optical signals at the first network degree to a second network degree in a second direction.

Abstract: System and method for improving performance in an optical link. The optical link includes a plurality of communication channels for transmitting an optical signal. The method is performed by a link controller of the optical link. The method comprises determining a noise level of at least one channel of the plurality of channels, determining a launch power offset for the at least one channel and performing link commissioning based at least in part on the launch power offset.

Abstract: An optical communications network comprises optical data links interconnected by add-drop nodes, the optical data links comprising data channels. The data channels are allocated into equal-sized bins. In response to a first data channel request between a given source-destination pair, one of the equal-sized bins is assigned to the data channel request. In response to requests for additional bandwidth for the same source-destination data channel request, unused channels within the assigned equal-sized bin are allocated to the data channel request. In response to subsequent data channel requests between different source-destination pairs, additional unallocated equal-sized bins are assigned to the subsequent data channel requests. In response to subsequent data channel requests when resource sharing for one equal-sized bin, data channels in the last equal-sized bin are assigned using the reverse channel assignment process. Reverse channel assignment can also be used for other bins as an option.

Abstract: To provide an optical branch coupler which facilitates communizing the design of an optical transmission path, the optical branch coupler comprising: a first add drop unit for outputting a third optical signal to a first line in which a first optical signal received from the first line and a second optical signal inserted into the first line are multiplexed and outputting the first optical signal; and a second add drop unit for receiving the first optical signal, receiving a sixth optical signal from a second line different from the first line in which a fourth optical signal and a fifth optical signal dropped from the second line are wavelength multiplexed, demultiplexing the fourth and fifth optical signals, and outputting a seventh optical signal to the second line in which the fourth optical signal and the first optical signal transmitted by the first add drop unit are multiplexed.

Abstract: One aspect of the present invention is a communication device including: a first control unit that converts, when data including partial data obtained by fragmenting a user frame and a user frame is received via a passive optical network, the partial data into data that is not discarded in a transmission line through which the user frame is transmitted, and transmits the data through the transmission line through which the user frame is transmitted; and a second control unit that receives the data via the transmission line through which the user frame is transmitted from the first control unit, converts the received data into a user frame that is transmittable through the passive optical network, and transmits the user frame via the passive optical network.

Abstract: Methods and systems concerning demultiplexing and multiplexing light in optical multiplexing systems are disclosed herein. An optical multiplexing system may include a number of light emitters and a number of associated waveguides. Light emitted from each of the number of light emitters may travel through the associated waveguide and may enter a multiplexer, where a multiplexing operation may occur. At least one of the number of light emitters may be configured to emit light with multiple wavelengths. Such a light emitter may further be associated with a demultiplexer to demultiplex the light with multiple wavelengths before the light reaches a multiplexer. After a demultiplexing operation, the demultiplexed light may be directed to multiple waveguides and the multiple waveguides may guide the demultiplexed light to a multiplexer.

Abstract: Device and method for processing an optical signal. The device includes a photonic device arranged between a first input/output and second input/output and optically communicating with the inputs/outputs by a signal path for transmission of an optical signal in a first or second direction between the first input/output and second input/output. The device includes an optical gain element for amplifying the optical signal. The device includes a path switching circuit including a first signal amplification path connectable between the first input/output and the photonic device for optically coupling the signal path to and from the optical gain element, and a second signal amplification path connectable between the photonic device and the second input/output for optically coupling the signal path to and from the optical gain element. The path switching circuit selectively connects the first or second signal amplification path into the signal path.

Abstract: A local wavelength defragmentation apparatus performs wavelength defragmentation for at least one wavelength path passing through a target link in an optical transmission network. The local wavelength defragmentation apparatus includes a reallocation rank determination unit configured to calculate a remaining time from a present time to an abolition timing for each of the at least one wavelength path and determine rank for wavelength reallocation of the at least one wavelength path based on the remaining time; and a reallocation number determination unit configured to calculate utilization of at least one reallocatable wavelength number for each of the at least one wavelength path according to the rank, and determine a wavelength so that a wavelength of the wavelength number having the highest utilization is reallocated.

Abstract: An undersea fiber optic cable architecture including a beach manhole (BMH) installed at a terrestrial site, a terrestrial station connected to the BMH by a terrestrial fiber optic cable, a first landing cable extending from the BMH into territorial waters adjacent the terrestrial site and connected to a first enhanced branching unit (EBU) located in the territorial waters, a second landing cable extending from the BMH into the territorial waters and connected to a second EBU located in the territorial waters, a recovery path cable connecting the first EBU to the second EBU, a first trunk cable extending from the first EBU into international waters, and a second trunk cable extending from the second EBU into the international waters.

Abstract: A coherent passive optical network includes a downstream transceiver and first and second upstream transceivers in communication with an optical transport medium. The downstream transceiver includes a downstream processor for mapping a downstream data stream to a plurality of sub-bands, and a downstream transmitter for transmitting a downstream optical signal modulated with the plurality of sub-bands. The first upstream transceiver includes a first local oscillator (LO) for tuning a first LO center frequency to a first sub-band of the plurality of sub-bands, and a first downstream receiver for coherently detecting the downstream optical signal within the first sub-band. The second upstream transceiver includes a second downstream receiver configured for coherently detecting the downstream optical signal within a second sub-band of the plurality of sub-bands. The downstream processor dynamically allocates the first and second sub-bands to the first and second transceivers in the time and frequency domains.

Abstract: [Problem] whether optical input interruption detected by an OXC device is due to an external failure from an upstream side or an internal failure of the OXC device in a transponder device connected to the OXC device using an optical transmission line, and this determination is implemented at low cost. [Solution] An optical transmission system (10A) is configured by connecting a plurality of OXC devices (14A) using optical fibers (16) between transponder devices (15A1) that relay optical signals transmitted to/from terminals (19a, 19b). The OXC device (14A) includes an OSC part (4d1) and a monitoring control part (4e1). The OSC part (4d1) outputs wavelength information on an optical signal in which optical input interruption has occurred and path information on a path of an optical fiber (16) in which the optical input interruption has occurred, at the time of detecting the optical input interruption from the optical fiber (16).

Abstract: An apparatus includes a reconfigurable optical add/drop multiplexer (ROADM) having an input port to receive a first optical signal from a second device. The ROADM also includes a first wavelength selective switch (WSS), in optical communication with the input port, to convert the first optical signal into a second optical signal, a loopback, in optical communication with the first WSS, to transmit the second optical signal, and a second WSS, in optical communication with the loopback, to convert the second optical signal to a third optical signal and direct the third optical signal back to the second device via the input port.

Abstract: 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.

Abstract: An apparatus includes a reconfigurable optical add/drop multiplexer (ROADM) having an input port to receive a first optical signal from a second device. The ROADM also includes a first wavelength selective switch (WSS), in optical communication with the input port, to convert the first optical signal into a second optical signal, a loopback, in optical communication with the first WSS, to transmit the second optical signal, and a second WSS, in optical communication with the loopback, to convert the second optical signal to a third optical signal and direct the third optical signal back to the second device via the input port.

Abstract: An optical backplane for an optical communication network architecture distributing data to equipment. An optical demultiplexer having an input port and at least two output ports. The input port coupled to an optical fiber to carry at least two multiplexed channels of different wavelengths, a control/management channel to control/manage the network and a service dedicated channel. The output ports deliver the control/management channel and at least one service dedicated channel. A coupler receives and transmits one portion of the control/management channel to an interface box coupled to an item of equipment, and another portion of said channel to an optical multiplexer. A routing device for each output port receives a channel either to transmit said channel to the optical multiplexer in a first position or to transmit one portion of said channel to the interface box and another portion of said channel to the optical multiplexer in a second position.

Abstract: Optical networks, nodes and methods are disclosed. To solve the aggressor issue and to reduce the cross-talk caused by the aggressors in colorless, directionless and contentionless reconfigurable optical add drop multiplexer nodes, the present disclosure configures a first broadcast module to supply only non-adjacent wavelengths to a first input port of a wavelength selective switch, and a second broadcast module to supply only non-adjacent wavelengths to a second input port of the wavelength selective switch.

Abstract: To use a plurality of wavelength bands, this seabed branching device comprises: a first demultiplexing unit that demultiplexes a wavelength multiplexed optical signal, which was input from a first terminal, into a first wavelength multiplexed optical signal and a second wavelength multiplexed optical signal; an optical add/drop unit that outputs at least a third wavelength multiplexed optical signal included in the first wavelength multiplexed optical signal to a second terminal station, and outputs at least a fifth wavelength multiplexed optical signal by multiplexing a fourth wavelength multiplexed optical signal included in the first wavelength multiplexed optical signal and a wavelength multiplexed optical signal input from the second terminal station; and a first multiplexing unit that multiplexes the second wavelength multiplexed optical signal and the fifth wavelength multiplexed optical signal, which was input from the optical add/drop unit, and outputs the result to a third terminal station.

Abstract: A frequency-selective system that may be used as, or as part of, an add/drop multiplexer. An input signal is fed to a Mach-Zehnder interferometer configured to drop, or suppress, by destructive interference, a signal component in a first frequency band from among a plurality of frequency bands. One or more bandpass filters in one arm of the Mach-Zehnder interferometer suppress other frequencies, outside of the first frequency band, so that signals at these other frequencies are not suppressed by destructive interference and are present at the output of the Mach-Zehnder interferometer. A coupler connected after the output of the Mach-Zehnder interferometer adds, into the signal path, a replacement for the dropped signal.

Abstract: An apparatus that adds and drops wavelength division multiplexed signal, the apparatus includes a memory and processor. The memory configured to store a first correspondence table indicating relationship with between an optical circuit type information and a first output level target value for a dropping circuit. The processor configured to determine an output level target value for the dropping circuit for each signal wavelength, based on the first correspondence table and optical circuit type information of each signal wavelength.

Abstract: An apparatus includes a reconfigurable optical add/drop multiplexer (ROADM) having an input port to receive a first optical signal from a second device. The ROADM also includes a first wavelength selective switch (WSS), in optical communication with the input port, to convert the first optical signal into a second optical signal, a loopback, in optical communication with the first WSS, to transmit the second optical signal, and a second WSS, in optical communication with the loopback, to convert the second optical signal to a third optical signal and direct the third optical signal back to the second device via the input port.

Abstract: Systems and methods include managing optical spectrum in an optical network utilizing a flexible grid where each channel in the optical network has a center frequency and utilizes a plurality of bins to define spectral width, wherein each channel's occupancy on the optical spectrum is enumerated by its center frequency and plurality of bins.

Abstract: A network node (400) for use as a hub node of a network that further comprises one or more remote nodes, wherein the network node (400) is coupled to at least first and second connections (410, 412) for communication with one or more remote nodes, comprises a first band filter (403) adapted to separate a first aggregated signal (404) comprising a plurality of channel signals into a plurality of band signals (4081 to 408M). The network node (400) comprises a second band filter (405) and a third band filter (407) adapted to aggregate a plurality of band signals (4081 to 408M) into a second aggregated signal (406) comprising a plurality of channel signals and a third aggregated signal (413) comprising a plurality of channel signals, respectively. A switching module (409) is adapted to switch on a per-band granularity the plurality of band signals (4081 to 408M) between the first band filter (403) and either the second band filter (405) or the third band filter (407).

Abstract: A network is provided with a plurality of nodes connected to one another. At least one node of the plurality of nodes include one or more transponders. For example, the transponders may be configured to receive optical signals having a first set of wavelengths at a first degree of a plurality of degrees in the at least one node. The transponders may convert the received optical signals into electrical signals, and then regenerate optical signals by generating, based on the electrical signals, optical signals having a second set of wavelengths. The node may further include one or more switches configured to route the regenerated optical signals to one or more of the plurality of degrees of the at least one node.

Abstract: An apparatus includes a reconfigurable optical add/drop multiplexer (ROADM) having an input port to receive a first optical signal from a second device. The ROADM also includes a first wavelength selective switch (WSS), in optical communication with the input port, to convert the first optical signal into a second optical signal, a loopback, in optical communication with the first WSS, to transmit the second optical signal, and a second WSS, in optical communication with the loopback, to convert the second optical signal to a third optical signal and direct the third optical signal back to the second device via the input port.

Abstract: A method and system is provided for cassette based wavelength division multiplexing and may include an optical system with an aggregating cassette. The optical system may include optical transceivers, with each generating optical signals at a different wavelength. The aggregating cassette may include one or more multiplexers coupled to each of the optical transceivers via optical fibers. The optical transceivers may generate modulated optical signals at one of the different wavelengths. The optical fibers may communicate one of the modulated optical signals from each of the optical transceivers to the one or more multiplexers. The modulated optical signals may be multiplexed to one or more output optical fibers. The multiplexed signals may be communicated to one or more receiving demultiplexers using the one or more output optical fibers. The one or more demultiplexers may demultiplex the multiplexed signals into separate wavelength signals.

Abstract: A frequency-selective system that may be used as, or as part of, an add/drop multiplexer. An input signal is fed to a Mach-Zehnder interferometer configured to drop, or suppress, by destructive interference, a signal component in a first frequency band from among a plurality of frequency bands. One or more bandpass filters in one arm of the Mach-Zehnder interferometer suppress other frequencies, outside of the first frequency band, so that signals at these other frequencies are not suppressed by destructive interference and are present at the output of the Mach-Zehnder interferometer. A coupler connected after the output of the Mach-Zehnder interferometer adds, into the signal path, a replacement for the dropped signal.

Abstract: Aspects of the subject disclosure may include, for example a housing defining an open volume therein where the housing includes a connection structure for connecting with a utility structure, a first wireless device contained in the housing where the first wireless device is coupled with a first antenna extending outside of the housing, and a second wireless device contained in the housing where the second wireless device is coupled with a second antenna extending outside of the housing. The first and second wireless devices can be coupled to each other. Other embodiments are disclosed.

Abstract: An intranodal reconfigurable optical add/drop multiplexer (ROADM) fiber management apparatus, and a system employing the apparatus. The apparatus comprises a plurality of ingress optical ports, a plurality of egress optical ports, and a plurality of optical interconnections interposed between ones of the plurality of ingress optical ports and ones of the plurality of egress optical ports. Each of the plurality of ingress optical ports corresponds to one of the plurality of egress optical ports. Each one of the plurality of ingress optical ports is optically coupled by way of the optical interconnections to at least one of the plurality of egress optical ports. Each one of the plurality of egress optical ports is optically coupled by way of the optical interconnections to at least one of the plurality of ingress optical ports.

Abstract: A technique for providing a synchronized clock signal across a wireless mesh network is described. The technique includes choosing one of a plurality received radio frequency signals to provide a synchronization signal to which a local clock signal can be synchronized.

Abstract: Example embodiments of the present invention relate to programmable ROADMs used to construct optical nodes. Example embodiments include wavelength switches and waveguide switches, wherein the waveguide switches may be programmed to direct wavelength division multiplexed optical signals to and from the wavelength switches.

Abstract: Provided is a wavelength path communication node device with no collision of wave lengths and routes, capable of outputting arbitrary wavelengths, and capable of outputting them to arbitrary routes. An add/drop multiplexer (11) includes a communication unit (101) that communicates an optical signal with at least one client device and at least one network and a control unit (102) that indicates a transfer destination of the optical signal according to an attribute of the received optical signal to the communication unit (101). The control unit (102) indicates an attenuation amount of the optical signal to the communication unit (101) for each connected device. When a connected device is changed, the control unit (102) instructs the communication unit (101) to change the attenuation amount. The communication unit (101) attenuates the optical signal with the attenuation amount indicated by the control unit (102) and transfers the attenuated optical signal to a transfer destination.

Abstract: A method and system is provided for cassette based wavelength division multiplexing and may include an optical system with an aggregating cassette. The optical system may include optical transceivers, with each generating optical signals at a different wavelength. The aggregating cassette may include one or more multiplexers coupled to each of the optical transceivers via optical fibers. The optical transceivers may generate modulated optical signals at one of the different wavelengths. The optical fibers may communicate one of the modulated optical signals from each of the optical transceivers to the one or more multiplexers. The modulated optical signals may be multiplexed to one or more output optical fibers. The multiplexed signals may be communicated to one or more receiving demultiplexers using the one or more output optical fibers. The one or more demultiplexers may demultiplex said multiplexed signals into separate wavelength signals.

Abstract: Provided is a hybrid network end system device for a network system with an end system unit and a switch. The switch here exhibits at least one first port of the switch and a second port of the switch for connection with the network system.

Abstract: A device and method for optical power measurement in an optical network supporting upstream and downstream signal propagation along an optical transmission path. The device includes an upstream wavelength analyzer receiving upstream light extracted from the optical transmission path and configured to determine an upstream spectral characteristic of the extracted upstream light. The device also includes a downstream filter assembly receiving downstream light extracted from the optical transmission path and configured to spectrally split the extracted downstream light into a plurality of downstream signals, one of which corresponding to a downstream signal of interest.

Abstract: A communication apparatus comprises a regular optical transceiver that generates regular subcarrier signals serving as subcarrier signals, a narrowband optical transceiver capable of generating narrowband subcarrier signals serving as subcarrier signals each having a narrower frequency band than the regular subcarrier signal, and a subcarrier configuration determiner that determines the configuration of a plurality of subcarrier signals in a super-channel signal, based on information on the number of optical filter stages to pass through. The regular optical transceiver shifts the positions of the regular subcarrier signals in the super-channel signal, according to optical frequency shift amounts indicating shift amounts of the plurality of subcarrier signals represented by the configuration determined by the subcarrier configuration determiner.

Abstract: A dense wavelength-division multiplexing (DWDM) optical network includes an optical input port configured to receive unmodulated optical signals from the optical fiber comprising wavelength channels; one or more modulators coupled to the optical input port wherein the one or more modulators are each configured to modulate a respective first wavelength channel of the wavelength channels with respective data to produce a modulated first wavelength channel when the modulator is in a transmit state; wherein an input optical power of each modulator is kept at substantially a first level and an output optical power of the each modulator is kept at substantially a second level during operation of the modulator. A method and an optical network node are also disclosed therein.

Abstract: Example embodiments of the present invention relate to a multi wavelength-routing-plane optical architecture. Example embodiments include a Reconfigurable Optical Add Drop Multiplexer (ROADM) supporting a multi wavelength-routing-plane optical architecture, and optical networks supporting a multi wavelength-routing-plane optical architecture.

Abstract: Embodiments of the disclosure relate to wireless distribution systems (WDSs) employing an optical star communications architecture based on quad small form-factor pluggable (QSFP) coarse wavelength division multiplexing (CWDM) transceivers. In one aspect, a selected QSFP CWDM transceiver among one or more QSFP CWDM transceivers wavelength multiplexes a plurality of downlink optical communications signals to generate a WDM downlink communications signal and provides WDM downlink communications signal to a selected remote unit branch among one or more remote unit branches in the WDS. In another aspect, the selected QSFP CWDM transceiver wavelength de-multiplexes a WDM uplink communications signal received from the selected remote unit branch into a plurality of uplink optical communications signals.

Abstract: Methods and systems for implementing a low noise CDC ROADM include incorporating individual stages of an optical PSA before and after WSSs included in the CDC ROADM. The WSSs may be used to route the pump and idler signals, as well as to perform phase tuning for optimal phase-sensitive amplification.

Abstract: A device may receive a request to establish a connection between a first device and a second device. The request may include information identifying a network connectivity type. The device may determine one or more network devices to provision based on the network connectivity type; determine, based on the network connectivity type, provisioning parameters used to provision the one or more network devices; and provision the one or more network devices in accordance with the provisioning parameters to establish the connection between the first device and the second device.

Abstract: A variation-tolerant receiver includes a plurality of receiver resonators configured to demultiplex a multiplexed modulated signal received from at least one wavelength division multiplexing (WDM) transmitter having a plurality of transmitter resonators and wherein operationally each of the receiver resonators has a receiver resonance linewidth not exceeding a minimum spacing between two adjacent transmitter resonances of the transmitter resonators, the receiver resonances collectively spanning a free spectral range of one of the receiver resonators such that the variation-tolerant receiver achieves gapless spectral response.

Abstract: An optical amplifier assembly for determining a parameter of an optical fiber configured to amplify an optical signal being propagated therethrough, the assembly comprising: at least one amplifier pump light source assembly configured to transmit light at a plurality of wavelengths into the optical fiber; a receiver configured to receive light that has propagated through at least part of the optical fiber; and a processor configured to determine the parameter of the optical fiber based on the received light.

Abstract: An optical add-drop multiplexer and a branching unit are provided, where implementation of the optical add-drop multiplexer includes: an optical processing component, a first combining device, a second combining device, and a second scrambler, where the optical processing component includes an input end, a first output end, a second output end, and a third output end; the first output end of the optical processing component is connected to a first input end of the second combining device, and the second output end of the optical processing component is connected an input end of the second scrambler; an output end of the second scrambler is connected to a second input end of the second combining device; and the third output end of the optical processing component is connected to a first input end of the first combining device.

Abstract: A free-space MCS may include an input port to launch a beam of light, N output ports, a beam splitter to split the beam of light into N portions, and a deflector array including N deflectors aligned in an array direction. Each deflector may have an active region with a size in the array direction that matches a size in the array direction of a portion, of the N portions, incident thereon. The free-space MCS may include first beam shaping optics to form a first elliptical beam spot at the beam splitter with a major axis substantially perpendicular to the switching direction, and an angle-to-offset element to direct each of the N portions from the beam splitter to a different deflector of the N deflectors. Each of the N portions may have, at the deflector, a second elliptical beam spot with a major axis substantially parallel to the switching direction.

Abstract: A method in an optical Wavelength Selective Switch, WSS, for multidirectional switching of optical signals. The optical WSS comprises a reflective element, a first tributary port and a second tributary port. The optical WSS switches (304) an optical signal between the first tributary port and the second tributary port with the reflective element.

Abstract: An optical communication system includes: a first network-side device and a second network-side device each coupled to a communication network; and a first terminal-side device and a second terminal-side device configured to communicate with the first network-side device and the second network-side device by being coupled to the first network-side device and the second network-side device via a first communication cable and a second communication cable, respectively, wherein the first network-side device is coupled to the first terminal-side device via the communication network, the second network-side device, and a third communication cable for coupling the second network-side device and the first terminal-side device so as to communicate between the first network-side device and the first terminal-side device.

Abstract: System and method embodiments are provided for optical I/O arrays for wafer scale testing. A wafer includes a plurality of dies of PIC chips. Each die includes a plurality of first and second optical I/O elements each configured to couple to a testing probe array. A row of I/O elements includes alternating ones of the first and second optical I/O elements. Each die also includes a first waveguide and a second waveguide coupling a first one of the first and second optical I/O elements to a second one of the first and second optical I/O elements, respectively. The first and second optical I/O elements configured such that the testing probe array couples to at least some of the first optical I/O elements from a first side of the PIC chip and couples to at least some of the second optical I/O elements from a second side of the PIC chip.

Abstract: Components of an optical communications network are described at a node of the network providing switching from one or more degrees of received optical signal routed to a plurality of receivers. The switch at the node generally includes a passive reconfigurable optical add drop multiplexer (ROADM) having drop or output ports that connector to optical channels leading to optical receivers without optical amplifiers between the ROADM outputs and the receivers. Configurations of the node and corresponding parameters are described that provide for use of lower cost components due to the absence of an array of optical amplifiers connected to the ROADM outputs.

Abstract: Methods and systems are provided for optical signal transmission using span-wise spectrum management. The method includes transmitting a first optical signal at a first wavelength by a control system. The first optical signal has a first optical path distance. The method further includes determining a first guard band requirement for the first optical signal, and transmitting a second optical signal by the control system. The second optical signal has a second optical path distance. The method includes determining a second guard band requirement for the second optical signal, and placing the second optical signal spectrally adjacent to the first optical signal by selecting a second wavelength. The second wavelength is selected to satisfy the first and second guard band requirements.