Abstract: A laser beam multiplexer capable of easily multiplexing a plurality of laser beams is provided. A laser beam multiplexer includes a multiplexing element having a hollow portion with a sectional elliptical shape, in which the multiplexing element includes: a plurality of light-incident apertures guiding laser beams from outside toward one of two focal points of the hollow portion, a reflective layer arranged on a wall surface of the hollow portion, and multiplexing a plurality of incident laser beams while reflecting the plurality of laser beams, and a light-emitting aperture guiding laser beams multiplexed by the reflective layer toward outside.

Abstract: Method and apparatus for operating for operating an optical network including a shared laser array are disclosed. An example apparatus includes include a first plurality of N lasers. Each laser of the first plurality of N lasers is configured to output a respective optical seed signal having a respective wavelength. The example apparatus further includes a first optical coupler coupled with the first plurality of N lasers. In the example embodiment, the first optical coupler is configured to multiplex the respective optical seed signals of the first plurality of N lasers onto a plurality of N optical fibers. In this example, each optical fiber of first plurality of N optical fibers transmits each of the respective optical seed signals produced by the plurality of N lasers to a respective distribution node for distribution to N respective optical network units, where the optical network units use the optical seed signals to seed respective optical transmitters located at the N optical network units.

Abstract: The technology described herein provides a low-cost three-port reconfigurable optical add-drop multiplexer (ROADM) with an improved edge profile and add/drop flexibility. The technology described herein further provides a tunable spectral filter utilizing two sets of gratings and lenses and a two-axis micro-electro-mechanical system (MEMS) mirror with a selectively shaped cut-out disposed within the middle of the collimated optical path.

Abstract: A packet-switched WDMA ring network has an architecture utilizing packet stacking and unstacking for enabling nodes to access the entire link capacity by transmitting and receiving packets on available wavelengths. Packets are added and dropped from the ring by optical switches. A flexible credit-based MAC protocol along with an admission algorithm enhance the network throughput capacity.

Abstract: Systems and methods provide for the addition of DWDM modules to CWDM systems in order to increase bandwidth over existing lines. This allows for the expansion of communications capacity without the need to replace existing CWDM systems. The DWDM modules can be transparently inserted into the CWDM systems by, in the CWDM system, reserving a channels for use by the DWDM. The DWDM system then occupies that channel with a scalable number of DWDM wavelength channels, for example four, eight, or sixteen. The DWDM systems can be used in both single and dual fiber systems as well as ring systems. Use of single fiber systems is obtained by implementing coupling devices, such as interleavers, passband filters, and circulators, that can used in pairs to couple bidirectional signals over a single fiber.

Abstract: An optical PON network comprises a central office which generates N DPSK modulated optical signals, where N is an integer greater than 1, an optical coupling which connects the N signals to at least one optical fibre, a passive distribution mode located remotely from the central office which has at least one input port that is coupled to the fibre and a plurality of output node being arranged to transmit a first wavelength of the N signals to at least one of its output ports, and at least one optical network unit connected through a respective optical fibre to the first output port of the passive distribution node. The passive distribution node comprises an arrayed waveguide grating which provides a passive optical connection between its input port and the first output port and which for that connection functions as a bandpass filter having a profile and bandwidth selected such that the DPSK optical signal passed to the input node is converted to an intensity modulated signal at the output port.

Abstract: A monolithic receiver photonic integrated circuit (RxPIC) chip includes a plurality of optical signal channels together with other active elements integrated on a semiconductor chip, which chips further include a wavelength selective decombiner comprising a supergrating or an Echelle grating which provides for a more compact chip compared to an integrated on-chip arrayed waveguide grating (AWG) functioning as a wavelength selective decombiner.

Abstract: The present invention provides a WDM optical system that includes a tunable filter for selecting one or more optical channels from a WDM optical signal. A portion of a WDM signal enters a first optical filter stage that exhibits a periodic transmission spectrum and possesses individually tunable filter elements. A second optical filter stage receives throughput from the first filter stage and has a periodic transmission spectrum and individually tunable filter elements. A controller electrically communicates with the optical filter to select individual optical channels from the portion of the wavelength division multiplexed optical signal received through the filter input port; each selected optical channel is output via a filter throughput port. In an exemplary embodiment, each tunable filter element is a micro-ring resonator and the micro-ring resonators in the first filter stage have a different free spectral range (FSR) than the micro-ring resonators of the second filter stage.

Abstract: Disclosed are various devices and methods employing photonic crystals to facilitate spatial separation of frequency components of a beam. In one embodiment, an apparatus is provided that includes a preconditioning waveguide facilitating a predefined amount of diffraction of a beam comprising a plurality of wavelengths. A photonic crystal is optically coupled to an output of the preconditioning waveguide. The photonic crystal is configured to spatially separate a plurality of frequency components of the beam.

Abstract: An apparatus and method are applied to characterizing an dispersion-affecting element for use in controlling chromatic dispersion in an optical communications link. Information regarding the behavior of the dispersion-affecting element is recorded and stored in a medium that is provided for deployment with the dispersion-affecting element to enable improved management and active control of the dispersion-affecting element. The suitability of the dispersion-affecting element for operating under different conditions may also be characterized.

Abstract: A light source apparatus with modulation function has a wavelength conversion module (75) composed of a nonlinear optical material with a structure having a nonlinear constant modulated periodically. It outputs a difference frequency or sum frequency produced by multiplexing pumping light from semiconductor laser light sources (71) and (72) with different wavelengths through a WDM coupler (74) and by launching the multiplexed light into the optical waveguide. The semiconductor laser light source (72) includes a diffraction grating. The semiconductor laser light source (71) includes a section for modulating output light emitted from its semiconductor laser, and is connected to an external FBG (73) which has a reflection band narrower than a resonance wavelength spacing determined by the device length of the semiconductor laser. The FBG (73) is supplied with the modulated output.

Abstract: A colorless tunable dispersion compensator for compensating for chromatic dispersion in a multi-channel light signal is provided. The compensator includes a multi-channel Bragg grating extending along a waveguide. Dispersion tuning means, such as a temperature gradient inducing device, are provided for tuning the dispersion characteristics of the wavelength channels. Wavelength shifting means are also provided for uniformly shifting the central wavelengths of all channels independently of their dispersion characteristics. A uniform temperature inducing or strain applying assembly can be used for this purpose.

Abstract: A detector includes a light detecting layer and a grating structure. The light detecting layer, which can be a photodiode, has an optical mode that resonates in the light detecting layer, and the grating structure is positioned to interact with the optical mode. The grating structure further couples incident light having a resonant frequency into the optical mode, and causes destructive interference to prevent light having the resonant frequency from escaping the detecting layer. The light detecting layer can be made transparent to light having other frequencies, so that a stack of such detectors, each having a different resonant frequency, can be integrated into a WDM detector that is compact and efficient.

Abstract: A chirp optical waveguide includes a chirp grating formed in a ferroelectric substrate, and a waveguide part orthogonal to the chirp grating. The chirp grating has a plurality of grating segments and has a normalized grating period ?x/?0 that increases exponentially in each grating segment and decreases stepwise from each grating segment to a following one of the grating segments, where ?0 is an initial grating period at the wave propagation distance of zero, and ?x is a grating period at the wave propagation distance of x. The chirp grating provides high wave conversion efficiency for short pulse widths and effectively compensates for a reduction in conversion efficiency due to chromatic dispersion.

Abstract: A wavelength division multiplexed-passive optical network includes an optical line terminal for generating downstream optical signals of discrete wavelengths and for receiving upstream optical signals of discrete wavelengths, a remote node, coupled to the optical line terminal, a wavelength division unit settled to reflect a predetermined wavelength, and a plurality of optical network units. Each optical network unit has an optical source which is oscillated in a multi-mode and is self-injection locked by the predetermined wavelength provided thereto, thereby to generate the upstream optical signal in a single mode to be provided to the remote node.

Abstract: An optical modulating circuit realizing a PPM is constituted by circuit parts having a frequency band equal to a data rate to provide a technique which increase the data rate. A first light source generates a first single wavelength signal serving as a continuous light having a first wavelength ?1 as a wavelength of a carrier wave. A second light source generates a second single wavelength signal serving as a continuous light having a second wavelength ?2 different from ?1 as a wavelength of a carrier wave. For the first single wavelength signal and the second single wavelength signal, according to a transmission electric signal having information 0 or 1, an optical switch outputs a first single wavelength signal as an input optical signal when the information is 0. On the other hand, when the information is 1, the optical switch outputs the second single wavelength signal as an input optical signal.

Abstract: Provided is a fiber ring laser capable of obtaining a back-up laser light and standard light having a wavelength continuously tuned in a single mode with equal spacing of 12.5 GHz, 25 GHz, 50 GHz or 100 GHz recommended by ITU-T Recommendation G. 692 & G. 694.1 in a C-band and an L-band using a fiber tunable etalon filter, an air gap etalon filter and a saturable absorber in an optical fiber laser resonator having a serial ring shape using a C-band optical amplifier and an L-band optical amplifier. The fiber ring laser can generate laser light having a wavelength tuned by more than 70 nm, excellent output power flatness and a source spontaneous emission ratio of more than 70 dB in 361 channels with equal spacing of 25 GHz by applying a bias voltage to a voltage-operated piezoelectric element of a tunable etalon filter. A single longitudinal mode operation of the fiber ring laser can be obtained by using a saturable absorber serving as a narrow-bandwidth filter.

Abstract: Provided are a frequency extracting apparatus and a signal extracting system employing the same. The signal extracting system can reduce the effect of an input signal pattern by extracting two frequency components and beating them to extract a desired clock signal, and improve a signal-to-noise ratio of an extracted clock signal. The frequency extracting apparatus includes: a circulator for changing an output direction of an input signal; a reflective filter for extracting a desired frequency component among frequency components of the input signal; a wavelength and amplitude controlling unit; and the frequency amplitude controller.

Abstract: Provided is a multimode optical transmission system capable of reducing an influence of multimode dispersion occurring when an optical signal is transmitted in multimode. Light sources (101 to 10m) respectively convert inputted electrical signals into a plurality of optical signals respectively having different wavelengths, and respectively output the plurality of optical signals. A wavelength multiplexing section (200) performs wavelength multiplexing of the plurality of optical signals outputted from the light sources (101 to 10m), and outputs a resultant signal as a wavelength multiplexed signal. A multimode optical transmission path (300) optically transmits the wavelength multiplexed signal in multimode. A mode processing section (400) extracts, from the wavelength multiplexed signal transmitted through the multimode optical transmission path (300), a plurality of optical signals each being in a mode having a particular wavelength and a particular propagation constant.

Abstract: A method for assuring a blazed condition in a DMD device used in telecommunications applications. By meeting certain conditions in the fabrication and operation of the DMD, the device can achieve a blazed condition and be very effective in switching near monochromatic spatially coherent light, thereby opening up a whole new application field for such devices. This method determines the optimal pixel pitch and mirror tilt angle for a given incident angle and wavelength of near monochromatic spatially coherent light to assure blazed operating conditions. The Fraunhofer envelope is determined by convolving the Fourier transforms of the mirror aperture and the delta function at the center of each mirror and then aligning the center of this envelope with a diffraction order to provide a blazed condition.

Abstract: In an optical fiber network bidirectional WDM traffic is sent on one optical main transmission fiber (1) between two nodes (A, B) connected in the path of the transmission fiber. The bidirectional traffic between a pair of nodes is carried on two different wavelength channels (Nos. 1, 2), one for each direction. The two wavelength channels are added to/dropped from the traffic in the ring fiber (1) in each node using a two-channel add/drop filter (5e1-2, 5w1-2), e.g. a band add/drop filter. In this way the number of add/drop filters connected in the path of the transmission fiber can be kept as small as possible.

Abstract: A method and system for ensuring confidentiality of signal transmission in a point-to-multi point data transmission network like Ether net passive optical network, including at least one hub, at least one transmission medium and at least one station connected to the hub via the transmission medium. When an upstream signal is transmitted from a first station, the upstream signal is reflected by at least one disturbing reflector for producing a disturbing reflection. The disturbing reflection combines with a second reflection of the upstream signal and renders the second reflection undependable by a second station.

Abstract: In one general embodiment, a method for deflecting an optical signal input into a waveguide is provided. In operation, an optical input signal is propagated through a waveguide. Additionally, an optical control signal is applied to a mask positioned relative to the waveguide such that the application of the optical control signal to the mask is used to influence the optical input signal propagating in the waveguide. Furthermore, the deflected optical input signal output from the waveguide is detected in parallel on an array of detectors. In another general embodiment, a beam deflecting structure is provided for deflecting an optical signal input into a waveguide, the structure comprising at least one wave guiding layer for guiding an optical input signal and at least one masking layer including a pattern configured to influence characteristics of a material of the guiding layer when an optical control signal is passed through the masking layer in a direction of the guiding layer.

Abstract: Transmission and reflection type holograms may be formed utilizing a novel polymer-dispersed liquid crystal (PDLC) material and its unique switching characteristics to form optical elements. Applications for these switchable holograms include communications switches and switchable transmission, and reflection red, green, and blue lenses. The PDLC material offers all of the features of holographic photopolymers with the added advantage that the hologram can be switched on and off with the application of an electric field. The material is a mixture of a polymerizable monomer and liquid crystal, along with other ingredients, including a photoinitiator dye. Upon irradiation, the liquid crystal separates as a distinct phase of nanometer-size droplets aligned in periodic channels forming the hologram. The material is called a holographic polymer-dispersed liquid crystal (H-PDLC).

Abstract: An apparatus and method are applied to characterizing an dispersion-affecting element for use in controlling chromatic dispersion in an optical communications link. Information regarding the behavior of the dispersion-affecting element is recorded and stored in a medium that is provided for deployment with the dispersion-affecting element to enable improved management and active control of the dispersion-affecting element. The suitability of the dispersion-affecting element for operating under different conditions may also be characterized.

Abstract: An apparatus and method for extracting an optical clock signal are provided. The apparatus includes a first reflection filter selecting and reflecting only a first frequency component in an input optical signal; a first Fabry-Perot laser diode matching the first frequency component reflected by the first reflection filter with a predetermined output mode and outputting the first frequency component in the predetermined output mode; a second Fabry-Perot laser diode selecting a second frequency component in an input optical signal that has not been reflected but has been transmitted by the first reflection filter, matching the second frequency component with a predetermined output mode, and outputting the second frequency component in the predetermined output mode; and a photodetector receiving the first frequency component from the first Fabry-Perot laser diode and the second frequency component from the second Fabry-Perot laser diode and beating them to extract a clock signal.

Abstract: A method of testing the electrical functionality of an optically controlled switch in a reconfigurable antenna is provided. The method includes configuring one or more conductive paths between one or more feed points and one or more test point with switches in the reconfigurable antenna. Applying one or more test signals to the one or more feed points. Monitoring the one or more test points in response to the one or more test signals and determining the functionality of the switch based upon the monitoring of the one or more test points.

Abstract: A method of optimizing a WDM optical ring network configuration using a genetic algorithm. Preferably, the method includes the steps of initially defining one or more parameters for a WDM optical network or portion of a WDM optical network and creating a plurality of parents each having a gene structure corresponding to the one or more parameters of the WDM optical network or portion thereof. The parents are then ranked according to predetermined fitness criteria. The highest ranking parents are then mated to form one or more children. Preferably, the children are then optionally mutated before or after testing to ensure that they satisfy predetermined network demands. Suitable children replace lower ranking parents to form new parents. The process is then repeated by mating the highest ranking parent in an effort to further optimize the network. Various steps in the genetic algorithm can be repeated until an optimal design is achieved.

Abstract: An optical module can achieve an optical system using a transmission-type diffraction grating for bending the optical path of incident light with a specific wavelength by about 90°. A substrate of the transmission-type diffraction grating is mounted at an angle in a range of ±5° with respect to the design incident angle ? of the incident light. The optical system can be applied to a light multiplexing/demultiplexing module.

Abstract: An optical fiber transmits at least a signal light having a wavelength of 1550 nanometers in a fundamental propagation mode. The optical fiber has, a cutoff wavelength equal to or longer than 1550 nanometers, a wavelength dispersion of 4 ps/nm/km to 7 ps/nm/km in the fundamental propagation mode at the wavelength of 1550 nanometers, a dispersion slope of a positive value equal to or smaller than 0.03 ps/nm2/km in the fundamental propagation mode at the wavelength of 1550 nanometers, an effective core area equal to or larger then 60 ?m2 in the fundamental propagation mode at the wavelength of 1550 nanometers, and a bending loss equal to or smaller than 20 dB/m with a winding of 16 turns at a diameter of 20 millimeters in the fundamental propagation mode at the wavelength of 1550 nanometers.

Abstract: Semiconductor electrooptic medium shows behavior different from a medium based on quantum confined Stark Effect. A preferred embodiment has a type-II heterojunction, selected such, that, in zero electric field, an electron and a hole are localized on the opposite sides of the heterojunction having a negligible or very small overlap of the wave functions, and correspondingly, a zero or a very small exciton oscillator strength. Applying an electric field results in squeezing of the wave functions to the heterojunction which strongly increases the overlap of the electron and the hole wave functions, resulting in a strong increase of the exciton oscillator strength. Another embodiment of the novel electrooptic medium includes a heterojunction between a layer and a superlattice, wherein an electron and a hole in the zero electric field are localized on the opposite sides of the heterojunction, the latter being effectively a type-II heterojunction.

Abstract: An apparatus for optical communication is provided. The apparatus includes a first waveguide formed on a first surface and a second waveguide formed on a second surface. The first and second surfaces are bonded together to form an air gap between the first and second surfaces and diffraction gratings of the first and second waveguides are facing each other. A third waveguide is formed on a third surface, and the third surface is bonded to the second surface so an air gap exists between the third and second surface and diffraction gratings of the third and second wave guides face each other. The light beam passes from the second wave guide across the air gap and into the third waveguide.

Abstract: A wavelength selective switch, in which an input optical signal is wavelength-dispersed and polarization-split in two angularly oriented planes. A polarization rotation device, such as a liquid crystal polarization modulator, pixelated along the wave-length dispersive direction such that each pixel operates on a separate wavelength channel, rotates the polarization of the light signal passing through the pixel, according to the control voltage applied to that pixel. The polarization modulated signals are then wave-length-recombined and polarization-recombined by means of similar dispersion and polarization combining components as were used to respectively disperse and split the input signals. The direction of the output signal is determined by whether the polarization of a particular wavelength channel was rotated by the polarization modulator pixel, or not. In this way, a fast, wavelength dependent, optical switch is provided, capable of use in WDM switching applications.

Abstract: An optical channel monitor is provided that sequentially or selectively filters an optical channel(s) 11 of light from a (WDM) optical input signal 12 and senses predetermined parameters of the each filtered optical signal (e.g., channel power, channel presence, signal-noise-ratio). The OCM 10 is a free-space optical device that includes a collimator assembly 15, a diffraction grating 20 and a mirror 22. A launch pigtail emits into free space the input signal through the collimator assembly 15 and onto the diffraction grating 20, which separates spatially each of the optical channels 11 of the collimated light, and reflects the separated channels of light onto the mirror 22. A ?/4 plate 26 is disposed between the mirror 22 and the diffraction grating 20. The mirror reflects the separated light back through the ?/4 plate 26 to the diffraction grating 20, which reflects the channels of light back through the collimating lens 18.

Abstract: A group delay compensation equalizer is disclosed that employs a single channel four-port WDM device for compensating the group delay experienced by a plurality of wavelengths transmitted over different paths. The transmission differential between two wavelengths is compensated by transmitting the two wavelengths through two different paths where the fiber length in reflecting the second wavelength is equal to the transmission time difference between the two wavelengths. The single channel four-port group delay equalizer effectively provides a unidirectional signal flow, as compared to the conventional equalizer that transmits optical signals bi-directionally. The present invention reduces the cost of a group delay equalizer by simplifying the use of multiple three-port WDM devices into a single channel four-port WDM device.

Abstract: A method of filtering optical signals (300) utilizing an optical fiber (100A-100D). The method of filtering optical signals (300) includes the steps (304) selecting an optical fiber (100A-100D) coupled to a source of optical signals, (306) disposing a core (102) in the bore (103) of the optical fiber (100A-100D) formed of a core material (105), (308) selecting a core material (105) to provide a waveguide within the optical fiber (100A-100D), (310) disposing an optical grating (114-1) in a first optical cladding layer (104) disposed about the core (102), (312) propagating an optical signal within the optical fiber (100A-100D) guided substantially within the core (102), (314) modifying a propagation path of selected wavelengths comprising said optical signal with the optical grating (114-1), and (316) determining selected wavelengths for which the propagation path is modified by selectively varying an energetic stimulus to the core (102) thereby tuning the waveguide.

Abstract: An optical multiplexer/demultiplexer comprising a member, of which first and second opposite planar surfaces are parallel to each other. The member includes therein a void, of which third and fourth opposite planar surfaces are in parallel to each other. An extension of a first line lying on the first planar surface and an extension of a third line lying on the third planar surface intersect each other in a cross section including the void of the member, a smaller one of intersection angles thereof being ?1. An extension of a second line lying on the second planar surface and an extension of a fourth line lying on the fourth planar surface intersect each other, a smaller one of intersection angles thereof being ?1. The third planar surface is provided on a part thereof with at least one high reflection coating film. The fourth planar surface is provided on a part thereof with at least one optical wavelength filter.

Abstract: A packet-switched WDMA ring network has an architecture utilizing packet stacking and unstacking for enabling nodes to access the entire link capacity by transmitting and receiving packets on available wavelengths. Packets are added and dropped from the ring by optical switches. A flexible credit-based MAC protocol along with an admission algorithm enhance the network throughput capacity.

Abstract: The present invention discloses a wavelength-division multiplexing passive optical network (WDM-PON) capable of high-bandwidth transmission for optical signals by using modulation format having high spectral efficiency. The WDM-PON according to the present invention provides a larger capacity and higher bandwidth transmission economically (at lower costs) by using a modulation format where spectral efficiency (a transmission bit number per a unit band width) is high, while using a low noise part of a light source.

Abstract: An optical device that processes a wavelength divisional multiplexed (WDM) optical signal includes an arrayed waveguide grating (AWG) and a polarizing liquid crystal array. The AWG demultiplexes and/or multiplexes the wavelength channels of the WDM signal. The liquid crystal array modulates the polarization state of individual wavelength channels so that each wavelength channel may be routed along an optical path based on the polarization state of the light.

Abstract: An optical code division multiplexing communication method includes the steps of: producing a multi-wavelength optical pulse train from wavelength multiplexing pulse; transmitting the multi-wavelength optical pulse train through a transmission line using a time-spreading/wavelength-hopping method; decoding wavelength multiplexing pulse from the multi-wavelength optical pulse train transmitted through the transmission line; compensating delay time differences between individual optical pulses of the multi-wavelength optical pulse train, the delay time differences occurring in the step of transmitting the multi-wavelength optical pulse train through the transmission line; and compensating optical pulse spread in a time direction, which occurs in each of the optical pulses of the multi-wavelength optical pulse train in the step of transmitting the multi-wavelength optical pulse train through the transmission line.

Abstract: A passive optical network component comprising a model-locked laser, a dispersive nonlinear fiber coupled to the model-locked laser, and a modulator coupled to the dispersive nonlinear fiber, wherein the model-locked laser provides wavelengths for downstream modulations and enables upstream transmissions from a colorless optical network unit (ONU). Also disclosed is a colorless ONU comprising an optical circulator coupled to an incoming optical path and an outgoing optical path, and an optical injection-locking component coupled to the optical circulator, wherein the colorless ONU uses downstream optical signals from a model-locked laser as seed light to enable colorless upstream transmissions.

Abstract: The invention relates to an apparatus and method for providing an improved optical pulse source suitable for use in high-speed optical communication systems. The optical pulse source can output spectrally pure pulses in a high capacity optical communication system. An optical pulse source in accordance with the invention comprises; at least one gain switched laser diode; and at least one non-linearly chirped optical processing element adapted to enhance the spectral purity of the output pulses generated from the laser diode.

Abstract: An optical network component, architecture and method for a wavelength division multiplexed passive optical network includes a band coupler configured to demultiplex first and second wavelength division multiplexed content transmitted from an optical line terminal into a first band signal and a second band signal. An arrayed wavelength grating is configured to receive the first band signal and to further demultiplex the first band signal into different wavelengths to provide a plurality of wavelength signals. An optical splitter is configured to split the second band signal into sub-signals and multiplex the sub-signals with each of the wavelength signals such that the first and second wavelength division multiplexed content is provided on a single wavelength to a user.

Abstract: An optical transmitter including a multi-lambda source to output injection light consisting of a plurality of injection wavelengths in channels, a circulator having a first port, a second port, and a third port, the circulator receiving the injection light at the first port, and outputting the received injection light to the second port, and further receiving signal light at the second port, and outputting the received signal light to the third port, an arrayed waveguide grating having a multiplexing port connected to the second port of the circulator, and a plurality of demultiplexing ports, spectrum-slicing injection light received from the circulator at the multiplexing port into a plurality of injection channels, and outputting the injection channels to the demultiplexing ports and further receiving and multiplexing a plurality of signal channels at the demultiplexing ports, into a signal light, and outputting the signal light to the multiplexing port, and a plurality of reflective semiconductor optical a

Abstract: The invention relates to wavelength-selective optical filters for allowing light of a narrow optical spectral band, centered around a wavelength (?c) to pass through them, while reflecting the wavelengths lying outside this band. According to the invention, the transfer function (T1,2(?)) of the component is defined by multiplying two transfer functions of spectrally offset Fabry-Perot filters.

Abstract: The present invention provides an optical wavelength-division multiple access system and a corresponding optical network unit. A wavelength band Da (wavelengths ?d1 to ?dn) for downlink optical signals corresponding to the n ONUs, a wavelength band Ua (wavelengths ?u1 to ?un) for uplink optical signals corresponding to the n ONUs, a wavelength band Db (wavelengths ?dn+1 to ?dn+m) for downlink optical signals corresponding to the m ONUs, and a wavelength band Ub (wavelengths ?un+1 to ?un+m) for uplink optical signals corresponding to the m ONUs are set different from one another, the wavelength bands Ua and Ub are set adjacent to each other, and the wavelength bands Ua and Da or the wavelength bands Ub and Db are set adjacent to each other.

Abstract: An optical assembly is formed with a silicon substrate having a first surface and a second surface confronting the first surface. A reflective coating is formed over the first surface. Multiple diffraction gratings are formed integrally within the second surface of the silicon substrate. An optical absorber is formed over the second surface between the diffraction gratings.

Abstract: The invention includes an apparatus for modulating an optical signal. The apparatus includes a spatial dispersion mechanism and a modulating mechanism. The spatial dispersion mechanism spatially disperses the optical signal. The spatially dispersed optical signal has a plurality of frequency components where each frequency component has an associated beam size. The modulating mechanism includes an array of modulating components where each modulating component has a pitch. The pitch of each modulating component is substantially equal to or less than the beam size of each frequency component.

Abstract: A slab optical waveguide confines in one transverse dimension optical signals propagating in two dimensions therein, and has a set of diffractive elements collectively arranged so as to exhibit positional variation in amplitude, optical separation, or spatial phase. The diffractive elements are collectively arranged so as to apply a transfer function to an input optical signal to produce an output optical signal. The transfer function is determined at least in part by said positional variation in amplitude, optical separation, or spatial phase. The waveguide and diffractive elements are arranged so as to confine only one of the input and output optical signals to propagate in the waveguide so that the optical signal thus confined is successively incident on the diffractive elements, while the other optical signal propagates unconfined by the waveguide in a direction having a substantial component along the confined dimension of the waveguide.