72 results about "Wavelength demultiplexer" patented technology

An optical coherent detector that employs an interleave-chirped arrayed waveguide grating (AWG). The AWG has a periodic chirp pattern that enables the AWG to function as an optical 90-degree hybrid. If the AWG is implemented using a birefringent material, then the AWG can also function as a polarization demultiplexer. In one embodiment, the AWG is designed to simultaneously function as a wavelength demultiplexer, a polarization demultiplexer for each wavelength-division-multiplexed (WDM) signal component, and a 90-degree hybrid for each polarization-division-multiplexed component of each WDM signal component.

An integrated etched multilayer grating-based wavelength multiplexer/demultiplexer is disclosed wherein an etched multilayer grating structure is monolithically integrated within the optical waveguide stack of the multiplexer/demultiplexer to reflectively diffract an input optical beam. The multilayer grating structure is generally comprised of a series of etched diffractive elements and an etched multilayer reflector, the combined optical response of which providing the desired multiplexing/demultiplexing effect. The etched structures are generally comprised of shallow etch structures in a top surface of the multiplexer/demultiplexer waveguide stack. Monolithically integrated input and output ridge waveguides may also be provided, optionally fabricated in a same etching step as the etched multilayer grating.

Apparatus connecting electrical circuit boards (1, 2, 3, . . . N) so each board can communicate with each other. Each board has an optical circuit, which in turn has a transmitter module (T) and a receiver module (R). The transmitter module (T) has electrical to optical converters (11B) for converting electrical signals into optical signals, a wavelength multiplexer (12) for multiplexing the optical signals into a single optical waveguide (12A), and an optical splitter (13) for dividing the multiplexed signal into a plurality of identical signals for transmission to each of the receiver modules (R). The receiver module (R) has an optical selector (14) for selecting signals from the transmission modules (T), a wavelength demultiplexer (21) for demultiplexing the selected signal into signals each of a different wavelength (lambd1 . . . lambdn), and optical to electrical converters (22B) for converting each of the signals of different wavelengths into an electrical signal.

The device includes following parts. The protection switches of 4 multiplexing segments are utilized to change optical fiber line. Two pair of wavelength division multiplexer/wavelength demultiplexer combines multiple optical signals with different wavelengthes onto one optical fiber; or separates the optical signals, which is combined from multiple different wavelengthes. N pieces of matrices with 4 in and 4 out of the optical switches are utilized to change the propagation direction or protect the channel needed. 2n pieces of optical power equalizers are used to balance the power of the optical signals. 2n+2 pieces of monitors are used to monitor and detect faults. The invention provides the flexible protection for channel faults, line faults and node device fault.

A wavelength routing system includes a plurality of nodes (1, 2, 3, 4) and an array waveguide grating (40) having a routing property and optically connected to the plurality of nodes. Each of the nodes has a plurality of light sources (TLS) outputting lights at different wavelengths to the array waveguide grating, respectively, and a wavelength demultiplexer (125, 225, 325, 425) having a periodic property, demultiplexing a light output from the array waveguide grating, and outputting demultiplexed lights. The wavelength demultiplexer is set a channel period which is different from that of the array waveguide, and which is more than or equal to a number of output ports of the wavelength demultiplexer.

An arrayed waveguide grating (AWG) based interconnection network and modular construction method, comprising N₁ left nodes, with each left node having N₂ ports, N₂ right nodes, with each right node having N₁ ports, where N₁≧N₂, N₁ and N₂ having a greatest common divisor r, and each port having an optical transceiver associated with a fixed wavelength; N₁n₂ r×1 wavelength multiplexers having their input ports respectively connected with the ports of N₁ left nodes, where n₂=N₂/r; N₂n₁ 1×r wavelength demultiplexers having their output ports respectively connected with the ports of N₂ right nodes, where n₁=N₁/r; n₁n₂ r×r AWGs connecting the r×1 wavelength multiplexers and the 1×r wavelength demultiplexers r×rn₁n₂, and each of the r×r AWGs being associated with a wavelength subset {λ_k|k=0, 1, . . . , r−1}.

A wavelength demultiplexer for demultiplexing optical signals carrying data, is also used to route a separate monitoring signal on to any of the demultiplexed output paths, by changing the wavelength of the monitoring signal. This enables optical paths through a switching arrangement to be verified or tested. A multiplexer at the output of the switching arrangement may be used to detect which of the output paths of the switching element has the monitoring signal. This saves the need for individual couplers to couple a monitoring signal on to each of the inputs, and off each of the outputs of the switching element. The saving in terms of component count, cost, and reduced size increases as the number of channels increases.

In the field of optical communication, the present invention is an optical multiplexer/demultiplexer capable of demultiplexing multiplexed optical signals of multiple wavelength regions into each wavelength region, or combining the light of each wavelength region. That is, the optical multiplexed light of wavelength λ1, λ2, λ3, λ4 is emitted from the optical fiber (9a), and its optical axis is bent by the microlens (12a) of the microlens array (14) to become parallel light, by Reflected by the plane mirror layer (19), it is incident to the filter layer (17). The filter (17a) only transmits light of wavelength λ1, so light of other wavelengths is reflected, reflected by the plane mirror layer (19) again, and enters the filter layer (17). The light transmitted through the filter (17a) is bent by the microlens (12c) to combine with the optical fiber (9c). Lights of wavelengths λ1, λ2, λ3, and λ4 are taken out from the light output ends of the optical fibers (9c, 9d, 9e, 9f), respectively.

A high resolution, wide spectral range, optical apparatus that includes an optical resonator cavity and a wavelength demultiplexer, arrangeable in multiple configurations. A method for increasing the resolution of a wavelength demultiplexer involves inputting light into an optical resonant cavity; inputting a plurality of different resonant output wavelengths to a wavelength demultiplexer; and routing each different resonant wavelength to a different output waveguide of the demultiplexer to generate a demultiplexer output spectrum. The method further involves performing either a time serialization or a space serialization procedure to increase the channel density and fully cover the spectrum of interest.

A receiver includes wavelength demultiplexer for demultiplexing a received WDM light into light signals at respective central frequencies thereof, delay interferometer for converting a light signal output from wavelength demultiplexer into an intensity signal, and light detector for converting an output signal from delay interferometer into an electric signal. The interval between interferential frequencies of delay interferometer is 2/(2n+1) times the interval between the central frequencies of the WDM light. Logic inverting circuit outputs the output signal from the light detector while non-inverting or inverting the logic level thereof depending on the received central frequency.

Proposed is an optical clock distribution system in the WDM network, which particularly relates to a system to control clock synchronization between optical transmission devices constituting an optical communication network. The optical clock distribution system includes an optical clock generator converting a clock signal of PRC (Primary Reference Clock) level into an optical clock signal having a wavelength lambd0; a wavelength multiplexer wavelength-multiplexing the optical clock signal having wavelength lambd0 together with other optical wavelength data; and a wavelength-demultiplexer provided in a unit of the network, wavelength-demultiplexing the optical clock signal having wavelength lambd0, wherein the other optical wavelength data are processed in the unit of the network using the wavelength-demultiplexed optical clock signal having wavelength lambd0 as a reference clock.

The optical exchaning matrix of sheared wavelength converter the comprises wavelength demultiplexer, space optical switching unit, the tunable wavelength shifter, the optical switch and the optical splitter/mixer. Each input port shares one wavelength shifter. The full wavelength shifter and the optical switch based on the lithium niobate wave-guide can be tuned by the four wave mixing based on the semiconductor light amplifeir. The space optical switching unit, which is composed of the optical splitter, the optical switch and the mixer, is adopted in the invention. Based on the control information sent from the control unit in the kernel node, the optical switches in the space optical switching unit as well as the optical switches between the wavelength shifter and the output port are controlled.

An optical circuit switching matrix includes a plurality of optical ports, each optical port being optically coupled to a respective one of a plurality of user nodes and an optical coupler having at least one input port optically coupled to the plurality of optical ports, and an output port. The optical circuit switching matrix also includes a wavelength demultiplexer having an input optically coupled to the output port of the optical coupler, and a plurality of output ports, each output port being optically coupled to a respective one of the plurality of optical ports.

An optical fiber sensor assembly comprises a source of a plurality of different frequency substantially monochromatic signals (1, 2, 3, 4); a modulator connected to the output of the source to produce a train of output pulses of the monochromatic signals; a plurality of sensor sub-assemblies connected to the output of the modulator, each sub-assembly comprising an optical drop multiplexer (ODM) (13), a sensor array (14) comprising a plurality of sensor elements and an optical add multiplexer (OAM) (15); a wavelength demultiplexer (WDM), having an input coupled to the sub-assemblies output; a plurality of detectors, each detector having an input connected to receive a respective output of the WDM and providing at an output thereof a signal corresponding to a respective frequency of the modulated monochromatic signals; and an interrogation system, having a plurality of inputs connected such that each input receives the output signal from a respective detector.

The invention discloses a fusion system of the radio over fiber (ROF) and the wavelength division multiplexing passive optical network (WDM - PON), and a signal transmission method of the same. According to the system, two sets of WDM - PON transmitter-receiver devices are arranged in a central office (CO), and on a remote node (RN), a cross multiplexing structure is arranged between two sets of WDM - PON optical fibers, and two optical network unit (ONU) receiving devices are correspondingly arranged at an ONUs receiving end. The signal transmission method comprises the steps of: downlink transmitting modules 1 - 16 transmit signals, and the signals enter a main optical fiber through a wavelength division multiplexing device and a circulator; on the RN, the signals enter receiving devices ONU 1 - ONU 16 correspondingly through a coupler (CP) 1, an opto-isolator, a CP 4 and a wavelength division demultiplexing device; and in the ONUs receiving end, the receiving devices ONU 1 - ONU 16 receive signals and modulate uplink signals and transmit the modulated uplink signals to uplink receiving modules 1 - 16 through the CP 4, the opto-isolator, a CP 3 and the main optical fiber correspondingly for uplink signal demodulation. According to the fusion system of the ROF and the WDM - PON, and the signal transmission method of the same, uplink transmission and downlink transmission of millimeter wave signals and baseband signals are enabled to be achieved at the same time, and backward rayleigh scattering of a single-fiber two-way transmission system is effectively avoided.

The invention discloses a compact wavelength division multiplexer and a compact wavelength demultiplexer. The compact wavelength division multiplexer and the compact wavelength demultiplexer both include an optical block, an input end and an output end, wherein the optical block includes a first side surface and a second side surface, wherein the first side surface is a reflecting surface which reflects light, and the second side surface is provided with a plurality of filters; light emitted by the input end is transmitted in the optical block; each time when the light is reflected to one filter, at least one part of the light passes through the filter, leaves the optical block and is emitted out through the output end; the second side surface is provided with a first refracting prism; light emitted from the input end is refracted by the refracting prism and enters the optical block; and an included angle between the light which is emitted from the input end and the light which passes through the filter is smaller than 20 degrees in the optical block. The compact wavelength division multiplexer and the compact wavelength demultiplexer of the invention have the advantages of simple structure, small size and the like.

A status estimation device for ultraviolet curable resin includes a probe configured to irradiate an ultraviolet curable resin with excitation light, a wavelength demultiplexer configured to receive fluorescence produced from the ultraviolet curable resin and detect spectral distribution of the fluorescence, and a computer configured to estimate status of the ultraviolet curable resin by comparing a shape of pre-irradiation spectral distribution detected when the ultraviolet curable resin is irradiated by excitation light before being irradiated by ultraviolet radiation with a shape of post-irradiation spectral distribution detected when the ultraviolet curable resin is irradiated by excitation light after being irradiated by ultraviolet radiation.

A multi-channel photonic demultiplexer includes an input region to receive a multi-channel optical signal including four distinct wavelength channels, four output regions, each adapted to receive a corresponding one of the four distinct wavelength channels demultiplexed from the multi-channel optical signal, and a dispersive region optically disposed between the input region and the four output regions. The dispersive region includes a first material and a second material inhomogeneously interspersed to form a plurality of interfaces that each correspond to a change in refractive index of the dispersive region and collectively structure the dispersive region to optically separate each of the four distinct wavelength channels from the multi-channel optical signal and respectively guide each of the four distinct wavelength channels to the corresponding one of the four output regions.

The invention relates to a method for demodulating the wavelength of a fiber grating by utilizing a linear tilt filter and belongs to the technical field of fiber grating wavelength demodulation. A device comprises an ASE (amplified spontaneous emission) light source, a 3db coupler, a fiber grating, the linear tilt filter, a wavelength demultiplexer, light intensity detection arrays and an A/D (analog to digital) converter, wherein the ASE light source is arranged in front of the 3db coupler; the fiber grating is arranged behind the 3db coupler; the 3db coupler is respectively connected to the linear tilt filter and the FBG (fiber bragg grating) through light guide fibers; the front end of the wavelength demultiplexer is connected to the linear tilt filter while the back end is connected to different light intensity detection arrays; and the light intensity detection arrays are electrically connected to a computer system through leads respectively, thereby realizing the wavelength demodulation through the computer. The device and method provided by the invention are low in cost, the monitoring method is simple and practical, and the device and method can be widely applied to various fields of production and living, such as temperature and stress monitoring.

The WDM receiver includes a wavelength demultiplexer, a detector array and a signal extractor. The wavelength demultiplexer receives an n-channel optical input signal and transmits the n-channel optical input signal to m optical outputs. Each of the optical outputs receives a wavelength band centered at a different wavelength. The wavelength bands have a center-to-center wavelength spacing of Δλ′. The detector array is composed of m detector elements coupled to the wavelength demultiplexer. Each of the detector elements generates a detection signal in response to light received from one of the optical outputs of the wavelength demultiplexer. The signal extractor receives the detection signals from the detector array and converts the detection signals to an n-channel receiver output signal, each channel of which corresponds to a different one of the n channels of the optical input signal. The WDM receiver is able to detect optical signals that are closely spaced in wavelength, even when the optical signals have off-center of varying wavelengths.