Abstract: A pull-back fiber cable installation for multi dwelling units includes a first distribution point disposed between a first group of twelve units and a second group of twelve units, a second distribution point disposed between a third group of twelve units and a fourth group of twelve units, and a twelve fiber distribution cable optically connected to the first and second distribution points. Each fiber of the distribution cable is cut between the first and second distribution point. A first portion of the cut fiber is spliced to a first drop cable that runs to a first unit of the second group of twelve units, and a second portion of the cut fiber is spliced to a second drop cable that runs to a first unit of the third group of twelve units.

Abstract: A sample holder includes a base comprising a support structure and a printed circuit board (PCB) in contact with the base. The PCB includes: a dielectric; a front-surface ground (GND) formed on a front surface of the dielectric; a back-surface GND formed on a back surface of the dielectric; a through hole penetrating from the front-surface GND to the back-surface GND, the through hole in which a chip is disposed, and a conductor that electrically connects the front-surface GND and the back-surface GND on an end face of the through hole. At least a part of the base below the through hole has a cavity. The support structure that supports a surface of the chip and is electrically connected to the base. The support structure is disposed in the cavity.

Abstract: A graded-index optical element may include a nanovoided material including a first surface and a second surface opposite the first surface. The nanovoided material may be transparent between the first surface and the second surface. Additionally, the nanovoided material may have a predefined change in effective refractive index in at least one axis due to a change in at least one of nanovoid size or nanovoid distribution along the at least one axis. Various other elements, devices, systems, materials, and methods are also disclosed.

Abstract: An acousto-optic deflector includes an optical element having a surface with one or more steps formed thereon; a conductive layer formed on the surface with the steps; one or more crystals secured to each step; and electrodes positioned on each surface of each crystal.

Abstract: An optical submarine branching apparatus 1 includes a control unit and a switching unit. The switching unit connects to a plurality of first optical fiber transmission lines connecting to a first terminal station, a plurality of second optical fiber transmission lines connecting to a second terminal station, and a third optical fiber transmission line connecting to a third terminal station, and switches a transmission route of a wavelength-multiplexed optical signal. The control unit controls the switching of the transmission route by the switching unit. The switching unit is configured to be capable of connecting each of the plurality of first optical fiber transmission lines to one of the plurality of second optical fiber transmission lines. The switching unit further is configured to be capable of switching any one of the plurality of first optical fiber transmission lines to connect to the third optical fiber transmission line.

Abstract: A quantum EIT-based optical switch includes a first waveguide, linear or nonlinear, a separate nonlinear waveguide evanescently coupled to the first waveguide, and a pump coupled to the nonlinear waveguide. A quantum STIRAP-based optical transduction device, which includes an auxiliary, intermediate spectral state for the quantum signal that aids efficient transduction of the quantum signal from the input spectral state to the output spectral state in a single device.

Abstract: A system and method for fabricating an optical element. The method includes welding an array of fibers to the optical element, measuring an angle error and a position error of each fiber, calculating a correction for each fiber for the angle error and the position error and correcting the angle and position of each fiber using the calculated corrections.

Abstract: An optical module has an optical port and an electrical port, and includes a shell, a circuit board, a circuit adapter board, a silicon optical chip, a light source and an optical fiber socket. The circuit board is disposed in the shell. One end of the circuit board is provided with a connecting finger located in the electrical port. The circuit adapter board is disposed on and electrically connected to the circuit board. A thermal expansion coefficient of the circuit adapter board is lower than that of the circuit board. The silicon optical chip is disposed on and electrically connected to the circuit adapter board. The light source is disposed on the circuit board, is electrically connected to the circuit board, and is optically connected to the silicon optical chip. The optical fiber socket is optically connected to the silicon optical chip, and is configured to form the optical port.

Abstract: Described herein are various embodiments directed to skipping the opening sequence of streaming content. An embodiment operates by streaming content to a display device and determining an end of a teaser portion has been reached using crowdsourced metadata. Responsive to the determining, a skin icon is provided to the display device for display. A selection of the skip icon is received to advance past the title sequence/opening credits portion of the content. An end to the title sequence/opening credits portion of the content is determined using the crowdsourced metadata. The streaming of the content is advanced to the end of the title sequence/opening credits portion of the content.

Abstract: A wireless communication apparatus includes a first conductor and a second conductor that function as a set of electrodes for wireless communication, a third conductor and a fourth conductor that function as another set of electrodes for wireless communication. A difference between a first distance between a centroid of the first conductor and a centroid of the third conductor and a second distance between a centroid of the second conductor and the centroid of the third conductor is less than a width of the first conductor and a width of the second conductor. A third distance between the centroid of the first conductor and a centroid of the fourth conductor is longer than the first distance. A fourth distance between the centroid of the second conductor and the centroid of the fourth conductor is longer than the second distance.

Abstract: An optical receptacle including a first optical surface configured to allow incidence of light emitted from the light emitting element; a second optical surface configured to emit, toward the optical transmission member, light emitted from the light emitting element and advanced inside the optical receptacle; and a diffraction surface disposed on the first optical surface, on the second optical surface, or on a light path between the first optical surface and the second optical surface. The diffraction surface is configured such that primary diffraction light of the light emitted from the light emitting element reaches an end portion of the optical transmission member, and that zero-order diffraction light of the light emitted from the light emitting element does not reach the end portion of the optical transmission member.

Abstract: A coupler array device may include an array of couplers arranged in a coupler plane, where each of the couplers couples light between the coupler plane and one or more directions outside of the coupler plane. A coupler array device may further include a pixel switch network to selectively couple light into or out of a selected subset of the plurality of couplers, where the pixel switch network may include one or more pixel-network waveguides and pixel-network switches to couple light between couplers and pixel-network waveguides. The coupler array device may further include one or more feed networks including a feed-line waveguide and one or more feed-network switches to couple light between the feed-line waveguide and at least some of the pixel-network waveguides. Light may be routable between selected couplers and selected feed-line waveguides along selected paths by controlling the pixel-network switches and the feed-network switches along the selected paths.

Abstract: A reconfigurable polarization rotator is formed of an array of very small liquid crystal (LC) cells (e.g., cells of less than 10 ?m in width, termed “microcells”), referred to hereinafter as “microcells”. Each LC microcell is addressable by a separate electrical voltage input that independently controls the polarization rotation performed by the associated LC microcell. By defining a set of adjacent microcells to be held at the same voltage level, that group may be used to form a polarization rotator window of a proper size for a first fiber array configuration. When a fiber array of a different configuration (say, an array with twice the pitch) is used, a different-sized group of adjacent LC microcells is held at a common voltage level so as to form a reconfigured “window” of a new dimension.

Abstract: A laser scanning microscopy system includes a laser whose beam is modified by an acousto-optic deflector that includes an optical element having a surface with one or more steps formed thereon; a conductive layer formed on the surface with the steps; one or more crystals secured to each step; and electrodes positioned on each surface of each crystal.

Abstract: The present disclosure relates to indexing cables for use in building fiber optic networks using an indexing architecture. In certain examples, fan-out structures are used. Certain types of indexing cables have one or more branch cable sections at each end. Certain types of indexing cables have multiple interface cable sections at one or both ends.

Abstract: A light detection and ranging (LIDAR) sensor includes a first reflective surface configured to oscillate about a first rotation axis to deflect a light beam into an environment; and a second reflective surface configured to oscillate about a second rotation axis to guide light received from the environment onto a photodetector of the LIDAR sensor. The first rotation axis and the second rotation axis extend parallel to one another. The LIDAR sensor also includes a control circuit configured to drive the first reflective surface to oscillate with a first maximum deflection angle about the first rotation axis, and to drive the second reflective surface to oscillate with a second maximum deflection angle about the second rotation axis, the first maximum deflection angle being greater than the second maximum deflection angle, and an area of the first reflective surface is less than an area of the second reflective surface.

Abstract: An optical signal processing method, a control unit, an optical transmission unit and a storage medium are disclosed. The optical signal processing method includes: acquiring an OSNR value from an optical receiving unit (S100); acquiring a spectrum shaping adjustment parameter according to the OSNR value (S200); and sending the spectrum shaping adjustment parameter to an optical transmission unit to adjust a filtering parameter of a shaping filter of the optical transmission unit, so that the optical transmission unit adjusts a spectrum waveform of an optical signal by utilizing the shaping filter after adjustment (S300).

Abstract: An optical network communication system utilizes a coherent passive optical network (PON). The system includes an optical line terminal (OLT) having a downstream transmitter and an upstream receiver system configured for time-wavelength division coherent detection. The system further includes a splitter in operable communication with the OLT, and a plurality of optical network units (ONUs) in operable communication with the splitter. Each of the plurality of ONUs is configured to (i) receive downstream coherent burst signals from the OLT, and (ii) transmit at least one upstream burst signal to the OLT. The upstream receiver system further includes a power control module and a local oscillator (LO) configured to generate an optical LO signal The power control module is configured to adaptively control, in real-time, a power level of the optical LO signal.

Abstract: A synchronous, tunable multi-optical filter system including two or more tunable optical filters, a shared diffraction grating, and a shared rotatable optical component, for example, a reflection prism, a mirror, etc., is provided. The shared diffraction grating, disposed in optical paths of both the tunable optical filters, disperses each collimated beam received therefrom into constituent wavelengths. By rotating the shared rotatable optical component disposed at a distance from the shared diffraction grating, using a rotation mechanism, the shared rotatable optical component communicates output beams having target wavelengths selected from the constituent wavelengths, to output elements of the tunable optical filters operating in individually configurable communication modes, for example, transmission and reflection modes.

Abstract: Some embodiments may include a fiber laser including two or more input fibers and an output fiber to deliver a beam to a workpiece, the fiber laser comprising. The fiber laser may include a combiner having ends and a length, wherein the combiner is arranged to release, from its length, a portion of back-reflected light received from the output fiber at an output end of the ends from the combiner, the combiner including: a capillary tube to enclose part of the two or more input fibers at an input end of the ends of the combiner, the capillary tube having ends and a length located between the ends of the capillary tube; and a cladding light stripper (CLS) defined by part of the length of the capillary tube, wherein the CLS provides the release of the portion of the back-reflected light. Other embodiments may be disclosed and/or claimed.

Abstract: The embodiments described herein describe technologies for using the memory modules in different modes of operation, such as in a standard multi-drop mode or as in a dynamic point-to-point (DPP) mode (also referred to herein as an enhanced mode). The memory modules can also be inserted in the sockets of the memory system in different configurations.

Abstract: Described are optical fibers, e.g., for use in stress-sensing or shape-sensing applications, that use overlapping grating configurations with chirped gratings to facilitate strain delay registration. In accordance with various embodiments, a fiber core may, for instance, have two overlapping sets of chirped gratings that differ in the direction of the chirp between the first and second sets, or a set of chirped gratings overlapping with a single-frequency grating. Also described are strain sensing systems and associated computational methods employing optical fibers with overlapping gratings.

Abstract: A balanced homodyne detection optical circuit according to the present disclosure is a planar optical waveguide circuit in which a circuit made of an optical waveguide including a dielectric or a semiconductor is formed on a substrate, the balanced homodyne detection optical circuit including an input port of local oscillator light and an input port of measurement light (squeezed light (including excitation light)), wherein a wavelength demultiplexing circuit which demultiplexes only the measurement light is arranged immediately after the input port of measurement light, a 50% multiplexing/demultiplexing circuit is arranged which causes squeezed light having been demultiplexed by the wavelength demultiplexing circuit and the local oscillator light to respectively branch at a branching ratio of 50% and to interfere with each other, and two output ports are arranged to which two outputs from the 50% multiplexing/demultiplexing circuit are guided.

Abstract: A gain medium is pumped by a source. An optical wave passes through a photonic integrated circuit (PIC) that comprises: a substrate comprising silicon, multiple photonic structures, an input port coupling an optical wave into a waveguide formed in the PIC, and an output port coupling an optical wave out of a waveguide formed in the PIC. Propagation of an optical wave circulating around a closed path of a laser ring cavity is limited using an optical isolator such that, when the pump source exceeds a lasing threshold, the optical wave propagates in a single direction through the gain medium and PIC. From an output coupler, an output is provided that comprises a fraction (e.g., >0.5) of the power of an optical wave that is incident upon the output coupler, and remaining power of the optical wave is redirected around the closed path of the laser ring cavity.

Abstract: In one example, an optoelectronic assembly may include a laser array, an amplifier array, and a multimode interference coupler optically coupling the laser array and the amplifier array. The laser array may include at least one primary laser and at least one spare laser configured to be activated if the primary laser fails. The amplifier array may include at least two amplifiers configured to amplify optical signals received from the laser array.

Abstract: In some examples, high speed bidirectional OTDR-based testing may include transmitting data from a first end of a device under test (DUT) towards an optical time-domain reflectometer (OTDR) that is operatively connected to a second opposite end of the DUT. Further data that is transmitted by the OTDR may be received from the second opposite end of the DUT towards the first end of the DUT. Based on an amplitude of the further data, a direction of receiving of the further data may be adjusted towards a first receiver or towards a second receiver.

Abstract: A phase-shifter for a light-transmitting waveguide is segmented into multiple segments that can be calibrated to the overall length of a conventional single phase-shifter. Each segment receives a control signal, which can be a single bit signal, with the phase-shift capability of the segmented phase-shifter controlled by which segment(s) receive(s) a control signal. In one implementation, a binary weighting is applied to determine segment lengths. Smaller segments can be increased in length to achieve a 2? offset of the phase shift produced by the segment while maintaining the same binary relationship among segments. In another embodiment, multiple segments of uniform lengths can be used for a single phase-shifter with each segment controlled by an n-bit signal.

Abstract: Embodiments discussed herein refer to LiDAR systems and methods that tune one or more filters to mitigate background interference. The one or more filters can be tuned to compensate for laser drift such that the narrowest possible bandpass filter can be used, thereby increasing the rejection of background interference.

Abstract: Optical components and methods of manufacture thereof. A first optical component has a hollow-core photonic crystal fiber includes internal capillaries for guiding radiation and an outer capillary sheathing the internal capillaries; and at least an output end section having a larger inner cross-sectional dimension over at least a portion of the output end section than an inner cross-sectional dimension of the outer capillary along a central portion of the hollow-core photonic crystal fiber prior to the output end section. A second optical component includes a hollow-core photonic crystal fiber and a sleeve arrangement.

Abstract: Structures for an edge coupler of a photonics chip and methods of forming an edge coupler for a photonics chip. The structure includes a waveguide core on a dielectric layer, as well as an interconnect structure including a interlayer dielectric layer positioned over the dielectric layer and an opening penetrating through the interlayer dielectric layer to the waveguide core. A region of the interlayer dielectric layer is positioned to overlap with a portion of the waveguide core. The region of the interlayer dielectric layer has a surface that is rounded with a curvature.

Abstract: An optical cable includes a single optical connector configured for insertion into an optical receptacle so as to receive optical signals at a plurality of different wavelengths from the optical receptacle, and multiple electrical connectors, configured for insertion into respective electrical receptacles. The optical cable further includes a plurality of optical fibers, having respective first ends connected together to the single optical connector so as to receive the optical signals. Each of the optical fibers has a respective second end coupled to a respective one of the electrical connectors. Each electrical connector includes a keyed portion to mate with an indentation on a transceiver.

Abstract: Embodiments include a fiber to photonic chip coupling system including a collimating lens which collimate a light transmitted from a light source and an optical grating including a plurality of grating sections. The system also includes an optical dispersion element which separates the collimated light from the collimating lens into a plurality of light beams and direct each of the plurality of light beams to a respective section of the plurality of grating sections. Each light beam in the plurality of light beams is diffracted from the optical dispersion element at a different wavelength a light beam of the plurality of light beams is directed to a respective section of the plurality of grating sections at a respective incidence angle based on the wavelength of the light beam of the plurality of light beams to provide optimum grating coupling.

Abstract: A method in a first level aggregation node of a transport network is disclosed. The transport network comprises the first level aggregation node, a second level aggregation node and a Passive Optical Network. T the method comprises receiving, from the second level aggregation node, a plurality of wavelength division multiplexing (WDM) channels having wavelengths in a first spectrum section and generating at least one passive optical channel having a wavelength in a second spectrum section, different to the first spectrum section. The method further comprises combining at least some of the WDM channels received from the second level aggregation node with the at least one passive optical channel, and forwarding the combined WDM channels and passive optical channel to a termination node in the Passive Optical Network. Also disclosed are a method in a termination node of a transport network, a first level aggregation node, a termination node and a computer program.

Abstract: Disclosed herein is wavelength-division multiplexing (WDM) and demultiplexing with signal entry and exit in a common routing surface to increase channel density. In particular, disclosed is a WDM assembly including a plurality of common ports and a plurality of channel sets having one or more channel ports. The WDM assembly includes a first routing surface with a first WDM passband and a second routing surface offset from the first routing surface. The second routing surface is configured to reflect at least one signal passed through the first routing surface back through the first routing surface at a laterally different location. Optical signal paths of at least a portion of the common ports are parallel to and offset from one another. In certain embodiments, such a configuration may increase channel density and decrease a form factor (e.g., footprint).

Abstract: Some implementations of the disclosure are directed to modulating a number roundtrips that light travels within a cavity to modulate optical depth. In one implementation, a display system includes: a display configured to emit light corresponding to an image; a first optical component positioned in front of the display, the first optical component configured to pass the light to a field evolving cavity (FEC); and the FEC, where the FEC includes a cavity entrance and a cavity exit, the cavity entrance configured to receive the light passed by the first optical component, the FEC configured with a polarization clock that modulates a number of round trips the light travels within the FEC, between the cavity entrance and the cavity exit, by changing a polarization of the light during each round trip.

Abstract: The systems described herein can be used to modulate either the phase, the amplitude, or both of an input light wave using micro-resonators to achieve desired degrees and/or types of modulation.

Abstract: The present invention is to provide an optical add/drop multiplexing device capable of realizing a configuration in which many transponders can be connected at low cost. An optical add/drop multiplexing device 30A includes branch function units 34a to 34d connected to each of WSSs 22a to 22d connected to respective routes 1 to D having a plurality of optical fibers and dropping optical signals having a plurality of wavelengths among the optical signals having the respective wavelengths transmitted by wavelength division multiplexing. The optical add/drop multiplexing device includes C-function units 35a to 35d configured to transmit the optical signals branched by the branch function units 34a to 34d to a plurality of transponders.

Abstract: Systems, methods, and computer-readable media are described for performing link training to enable optical pass-through (OPT) capabilities of a network node. OPT capabilities may refer to on-chip wavelength routing for a multi-wavelength data input, whereby an intermediate node detects wavelengths that are intended for OPT and transparently passes the wavelengths through to downstream nodes. When executed at an intermediate network node, an OPT link training algorithm can result in the creation of one or more wavelength routing maps that associate wavelengths received on particular inputs to the node with particular outputs of the node. An intermediate node may generate a respective wavelength routing map for each transmit node from which it receives input data. The wavelength routing maps may together implement OPT capabilities at the intermediate node as each wavelength routing map may indicate the manner in which wavelengths are passed through the intermediate node for a given transmit node.

Abstract: Structures including an edge coupler, and methods of fabricating a structure that includes an edge coupler. The structure includes an edge coupler having a waveguide core with an end surface and a longitudinal axis. The end surface defines a plane tilted in a first direction at a first acute angle relative to the longitudinal axis and tilted in a second direction at a second acute angle relative to the longitudinal axis. The second direction differs from the first direction.

Abstract: Filter media and media packs that provide robust performance in high-speed rotating coalescer (HSRC) elements for crankcase ventilation systems are described. The fiber media is HSRC fiber media. As such, the filter media has a higher resistance to compressibility then traditional coalescer filter media, such as fiber media used in low-speed rotating coalescer arrangements or stationary coalescer arrangements.

Abstract: A discrete wavelength tunable laser having an optical cavity which comprises: a reflective semiconductor optical amplifier (SOA); a demultiplexer (Demux) having a single input and a plurality of outputs, the Demux configured to receive the output of the SOA and to produce a plurality of fixed spectral passbands within the gain bandwidth of the SOA; one or more tunable distributed Bragg reflector(s) (DBR(s)) arranged to receive the outputs of the Demux, each tunable DBR configured to select a reflective spectral band within the gain bandwidth of the SOA upon application of a bias current; wherein the SOA forms the back end mirror of the optical cavity; the one or more tunable DBRs form the front end mirror of the optical cavity; and wherein the lasing channel of the discrete wavelength tunable laser is chosen by the overlap of the selected reflective spectral band of one of the one or more tunable DBRs with a fixed spectral passband of the Demux.

Abstract: Coherent optical communications technology for recovery of 1D and 2D formatted optical signals. For example, 1D or 2D formatted signals that travel through fiber optic media may be recovered by separating the light into X- and Y-polarization components, rotating one polarization component (e.g., Y-component) into the polarization space of the other component (e.g., Y-component into the X-polarization space), delaying the rotated component enough to avoid destructive interference and combining the delayed component with the undelayed component to form a folded optical signal, which may then be processed as a X-polarized signal.

Abstract: An object is to provide an optical communication system capable of controlling the output ratio by port and by wavelength for incident light of different wavelengths, a method of determining the split ratio of an uneven-split optical splitter for controlling the output ratio by port and by wavelength, and a transmission range determination method for the optical communication system. The split ratio determination method for an uneven-split optical splitter according to the present invention uses the melt-draw distance to adjust the split ratio of each fiber-optic splitter included in the uneven-split optical splitter such that the light output from the farthest ONUs among each of the ports connected under the ports B to M of the uneven-split optical splitter arrives with the minimum reception sensitivity at OLT receivers in a PON system.

Abstract: Structures for response shaping in frequency and time domain, include an optical response shaper and/or a modulator device with multiple injection. The device comprises a resonator having an enclosed geometric structure, for example a ring or racetrack structure, at least two injecting optical waveguides approaching the resonator to define at least two coupling regions between the resonator and the injecting waveguides, and may define at least two Free Spectral Range states. One or both of the coupling regions has a coupling coefficient selected for a predetermined frequency or time response, and the coupling coefficient or other device parameters may be variable, in some case in real time to render the response programmably variable.

Abstract: A probe tip of an oximeter device includes first and second printed circuit boards (PCBs) that are coupled to the ends of optical fibers that transmit light between the PCBs and into patient tissue that is to be measured by the oximeter device. The PCBs are oriented at an angle between zero and ninety degrees so that the fibers have a curved shape between the locations at which the fibers are coupled to the first and second PCBs. The angular orientation of the PCBs and curved shape of the fibers allows the fibers to have a longer length than if the fibers were straight and allows for light transmitted through the fibers to have a uniform distribution across a cross-section of the fibers as the light is emitted from the fibers into patient tissue. The uniform distribution of light transmitted into patient tissue allows for reliable oximetry measurements.

Abstract: A passive optical network includes one or more multi-service terminals each having a housing and a plurality of ruggedized plug-receiving distribution ports accessible from outside the housing. The multi-service terminals also each include an optical power splitter or wave division multiplexer for splitting an optical signal and directing the split signal to the plug-receiving distribution ports. Some of the multi-service terminals provide a different power split ratio from others of the multi-service terminals.

Abstract: An optical modulator of an optical transceiver can be calibrated using intermediate frequency (IF) signals to generate accurate crossing point values (e.g., DC bias). A photodiode can measure output from the optical modulator at intermediate and high-speed frequencies to generate crossing point values that avoid crossing point errors. A target crossing point can be selected at any value (e.g., 40%, 50%) and bias values can be generated from IF signals and then stored in a lookup date for setting the modulator bias during operation.

Abstract: Systems and methods for strategizing the insertion and/or removal of a node into and/or out of a network are provided. A system, according to one implementation, includes a processing device and a memory device configured to store a computer program. The computer program includes instructions that, when executed, enable the processing device to configure a Network Element (NE) in a pass-through mode whereby channels are neither added nor dropped to thereby prepare the NE for insertion into or removal from a photonic network. Upon the insertion of the NE into the photonic network or the removal of the NE from the photonic network, the instructions may further enable the processing device to perform a zero configuration procedure for automatically establishing communication along one or more Optical Service Channels (OSCs) and for automatically controlling gain and loss characteristics along one or more fiber links altered by the insertion or removal.

Abstract: A liquid crystal on silicon (LCOS) device includes a silicon substrate and a pair of electrodes including an upper and a lower electrode. The lower electrode is mounted to the silicon substrate and includes a two dimensional array of pixels extending in both a first and second dimension. LCOS device also includes a liquid crystal layer disposed between the upper and lower electrodes and configured to be driveable into a plurality of electrical states by drive signals provided to the pixels of the lower electrode. The pixels are rectangular in profile having longer sides in the first dimension than in the second dimension. Further, the two dimensional array includes a pixel pitch that is greater in the first dimension than in the second dimension.

Abstract: An optical network including a plurality of gateway nodes interconnected with a plurality of intermediate nodes with segments of fiber. The network includes a plurality of devices, such as reconfigurable optical add drop multiplexers, optimally placed at various nodes throughout the network. The device placement is optimized with an integer linear programming analysis considering span definition such that any given span involves some number of segments not exceeding a number of segments that would require wavelength regeneration, cost of placement of a device at a given node, cost of wavelength regeneration, and various parameters and constraints.