Abstract: An apparatus and a method for personal identification include an image pickup section for picking up an image of a blood vessel pattern of a wrist, a storage unit for storing in advance an image of a blood vessel pattern of a certain person as a registered image, and a control section (CPU) for the computation of degrees of similarity according to data differences between the image of the blood vessel pattern picked up by the image pickup section and the registered image to determine identification according to the relationship between the computed degrees of similarity and a threshold, thereby eliminating the need to carry out processing by a characteristic extraction section or the like.

Abstract: Methods and systems are described herein for high-speed observation and recognition of an object which is within or passes through a designated area using 3D image data and tomography, stereo-photogrammetry, range finding and/or structured illumination. Such a security system may comprise multiple pairs of 3D sensors surrounding the designated area such as a portal or doorway. Alternatively, it may comprise a 3D sensor which is capable of acquiring 3D image data of an object that is situated in front of it. Using at least one 3D sensor and a 3D data collection technique such as structured illumination and/or stereo-photogrammetry, 3D image data of the object is acquired. 3D image data representing the object's surface may be determined based on the acquired data and may be compared to data representing known objects to identify the object. Methods for fast processing of 3D data and recognition of objects are also described.

Abstract: A redeye reduction system creates a first matrix of candidate pixels by comparing a color-and-brightness parameter of image pixels to a first threshold. Cohesive groups of candidate pixels are collected into components, and the component having the pixel with the highest color-and-brightness parameter is identified as first redeye region. The average color-and-brightness parameter and the size of the remaining components are compared to a range dependent on the values of the first redeye region, and the components having values within the range are defined as candidate components. The candidate component with the densest pixel population is defined as a second redeye pupil region. The defined redeye pupils are dilated and compared with a second threshold lower than the first threshold to generate a new list of candidate pixels. The new candidate pixels are colored dark gray and their adjacent pixels are colored a lighter gray.

Abstract: Described herein is a technique for creating a 3D face model using images obtained from an inexpensive camera associated with a general-purpose computer. Two still images of the user are captured, and two video sequences. The user is asked to identify five facial features, which are used to calculate a mask and to perform fitting operations. Based on a comparison of the still images, deformation vectors are applied to a neutral face model to create the 3D model. The video sequences are used to create a texture map. The process of creating the texture map references the previously obtained 3D model to determine poses of the sequential video images.

Abstract: A highly accurate identification system is built by using an identification module, which has predetermined values of FAR and FRR. A plurality of (m) biometrics are registered and managed. At the time of identification, a collation process is executed by using the m biometrics, and also a collation process is executed a plurality of (n) times with each biometrics. An identification result of the system is judged and outputted by combining the results of the m-biometrics collation and n-time collation trials. As conditions of judgment, when the collation is judged to be successful even once in the n-time collation trial, the collation is judged to be successful with respect to that biometrics. In the in-biometrics collation trial, when the collation is judged to be successful with respect to all the m biometrics, a judgment of identification success is given in the system as a whole.

Abstract: An apparatus and method for imaging a sample, the apparatus including a source for irradiating a sample with a beam of substantially continuous electromagnetic radiation having a frequency in the range 25 GHz to 100 THz; means for subdividing an area of the sample which is to be imaged into a two dimensional array of pixels; means for detecting radiation from each pixel wherein the detector is configured to detect a phase dependent quantity of the detected radiation which is measured relative to the radiation which irradiates the sample.

Abstract: A method for detecting and attenuating grid artifacts in a digital radiographic image comprising; providing an input digital radiographic image; processing the input digital radiographic image with a detection algorithm based on 2-D dynamic correlation in both spatial and frequency domains to determine whether the input digital radiographic image has a grid artifacts; and if it does detecting the grid orientation, frequency, and signal-to-noise ratio of the grid artifacts, designing a frequency bandstop (notch) digital 1-D filter as a function of the grid frequency and attenuation level; and suppressing the grid artifacts by further processing said input digital radiographic image with said designed filter to produce an output digital radiographic image of improved image quality.

Abstract: A virtual reality embodying system uses 2D images and HDRI data taken of a target object through a camera to embody virtual reality. A modeling unit compares the 2D image's coordinate with a real coordinate to calculate a transform matrix, calculates a vanishing point of a reference vector, uses the vanishing point to calculate a camera matrix, uses the camera matrix and the transform matrix to calculate a rotation matrix and a translation matrix, and uses the rotation matrix and the translation matrix to model the 2D image into a virtual model. A rendering unit uses the HDRI data as texture to render the virtual model, and embodies the HDRI into an extended VRML node to apply the virtual model to the VRML environment.

Abstract: A procedure for fast training and evaluation of support vector machines (SVMs) with linear input features of high dimensionality is presented. The linear input features are derived from raw input data by means of a set of m linear functions defined on the k-dimensional raw input data. Training uses a one-time precomputation on the linear transform matrix in order to allow training on an equivalent training set with vector size k instead of m, given a great computational benefit in case of m>>k. A similar precomputation is used during evaluation of SVMs, so that the raw input data vector can be used instead of the derived linear feature vector.

Abstract: A diagnostic apparatus in an image recognition system able to quickly and accurately detect breakage of a cable from an image sensor or pixel burn of an image sensor, provided with a histogram computing unit for performing predetermined computations on an image signal fetched into an image recognition unit to generate a density histogram and an abnormality judging unit for analyzing the density histogram generated by the histogram computing unit to judge the presence of an abnormality or alternatively provided with a memory unit for receiving as input and storing information of an image signal fetched into an image recognition unit and a comparing/judging unit for reading out and comparing information of image signals of a plurality of images different in time relating to a target pixel from the memory unit and judging whether they are the same or different and judging that there is an abnormality when they are the same.

Abstract: A user can enter handwritten electronic ink into a writing guide on an electronic page of an electronic tablet. An ink processing module can display the handwritten electronic ink as it is rendered on the electronic page by the user. Upon the occurrence of a predefined event, the writing guide module can automatically recognize and convert the electronic ink to text without the user's manual intervention. The writing guide module can replace the electronic ink in the writing guide with the converted text.

Abstract: A character recognizer recognizes a handwritten input character. A sequence of points in two dimensional space representative of a stroke trajectory forming the input character is gathered. An input Directed Acyclic Graph is built with nodes representative of singular points at the beginning, end, and along the trajectory of the input character and with edges between nodes representative of an edge trajectory formed by the sequence of points of the input character between the singular points. Each edge in the input graph is described based on the shape, orientation and pen lift of the edge trajectory that the edge represents. The input graph is evaluated against model graphs, which are also Directed Acyclic Graphs, for all possible characters to find a path through a model graph that produces a best path similarity score with a corresponding path through the input graph. The input character is identified as an answer character represented by the model graph producing the best path similarity score.

Abstract: In a method for character recognition based on Gabor filter group the Gabor filter's joint spatial/spatial-frequency localization and capability to efficiently extract characters' local structural features are employed to extract, from the character image, information of the stroke direction of characters as the recognition information of characters, so as to improve the capability to resist the noises, backgrounds, brightness variances in images and the deformation of characters. Using this information, a simple and effective parameter design method is put forward to optimally design the Gabor filter, ensuring a preferable recognition performance; a corrected Sigmoid function is used to non-linearly adaptively process the stroke direction information output from the Gabor filter group. When extracting the feature from blocks, Gaussian filter array is used to process the positive and negative values output from Gabor filter group to enhance the discrimination ability of the extracted features.

Abstract: An image compression apparatus and method, and a carrier wave encoded with a computer readable control program having instructions for use by a computer, perform an image compression process. A compression level is determined for use in compressing a picture image to a predetermined target data amount by iteratively compressing a reduced version of the picture image in order to determine the compression level that is to be used to compress the picture image. First, a reduced-size picture image is created from the picture image that is to be compressed. A preliminary compression target data amount is then derived, for example, based on the target data amount, the data amount of the picture image and the data amount of the reduced-size picture image. The reduced-size picture image is then compressed using a compression level. The size of the resulting compressed reduced-size picture image is compared to the preliminary compression target data amount.

Abstract: A monitoring unit monitors continuously wavelet transform component output from a wavelet transformer. When a condition “make all the components of the HH sub-band 0” is applied as a quantization strategy, the monitoring unit detects the maximum value N among the components in the HH sub-band and determines the threshold as N+1. The threshold is then sent to a quantizer.

Abstract: In a video encoder/decoder, a method processes a discrete cosine transform (DCT) block of coefficients. The method receives a DCT block of coefficients, and linearizes the DCT block of coefficients into a one dimensional array of sequentially arranged coefficients. The method stores a portion of the one dimensional array of coefficients in a register, the portion including at least two sequentially arranged coefficients. The stored portion of coefficients in the register is processed. A next portion of coefficients in the one dimensional array is processed. This is repeated until the entire DCT block of coefficients have been loaded into the register. The processing may include computing a run length value, finding a class number, or determining dequantized coefficients of a DCT block.

Abstract: A data analyzer/classifier comprises using a preprocessing step, and energy minimization step, and a postprocessing step to analyze/classify data.

Abstract: An image upscaling algorithm jointly optimizes estimating pixel color, classifying it into one of multiple regions, and estimating region boundaries subject to region continuity and edge-configuration constraints. The joint solution of constraints at multiple levels of image abstraction leads to improved image reconstruction quality. The algorithm involves subdividing the image signal into multiple distinct regions, including an upper region and a lower region, and at least one transition zone between the upper and lower regions; constructing a plurality of separate curves, one for each region; smoothing each curve independently of the other curves; and reconstructing the image signal from the smoothed curves such that the reconstructed image signal has no segment in any transition zone.

Abstract: A method, system, and computer program product for adjusting a unit image area within an input image according to information importance within the unit area. An image receiver configured to receive the input image. An image warper is coupled to an importance map as is configured to generate a warped image such that regions of higher importance in the input image are expanded in the warped image and regions of lower importance in the input image are compressed in the warped image. The importance map is configured to delineate the regions of higher importance and the regions of lower importance in the input image. Texture coordinates may also be warped in a similar manner. Thus, the image is unwarped automatically by modern graphics adapters having texture mapping capabilities.

Abstract: A data processing apparatus is capable of executing a plurality of signal processes. The data processing apparatus switches processes of a pre-processing portion, a data processing portion, and a post-processing portion with a control signal supplied from a function controlling portion corresponding to a command supplied from the outside. Thus, the data processing apparatus executes for example processes for increasing the resolution, generating a picture dedicated for a right eye and a picture dedicated for a left eye, generating a luminance signal and color difference signals, changing the aspect ratio, generating pictures having difference resolutions, and converting the frame rate for input data corresponding to a request and outputs picture data generated as the processed result to an external device (for example, a displaying device and a record and reproduction device).

Abstract: A method and an apparatus for fault-tolerant computing in a parallel processing environment. Intermediate data points are determined from a set of input data by a plurality of processing elements operating in parallel. Preferably, the resolution of the intermediate data points is greater than the resolution required in an output imaging data set. The intermediate data points are spatially re-gridded to the resolution required in the output imaging data set, ignoring any missing data as a result of a processing element failing.

Abstract: Thumbnail images are promptly created while reducing the required memory capacity for storing the thumbnail images. When input (of an image or a command) is not completed in more than a prescribed time period, only the picture images photographed on that day from among the photo-images stored in a memory are read to create thumbnail images. The created thumbnail images are stored in a buffer memory. When set to the reproduction mode, the thumbnail images stored in the buffer memory are read and displayed on a screen in a list format. Furthermore, when the power is in the OFF position, the thumbnail images stored in the buffer memory can be deleted.

Abstract: Methods and apparatus of the invention enable users to request access to one or more electronic images of pages in a physical text. When the user is identified and user ownership of the physical text is confirmed, the user is given access to the requested electronic images in accordance with the one or more access rules. Electronic images of pages may be automatically added to a user-personalized library of electronic content for later access. A flag associated with the user and the pages images may be set to indicate confirmed user ownership of the physical text. A user may purchase a physical text itself or purchase an item that the physical text normally accompanies. Electronic page images may be acquired by scanning printed pages of the text or from a user upload. Access to the electronic images of a physical text is based on user ownership of the physical text.

Abstract: Video frames of original video data are sampled with arbitrary time interval and size, and thumbnail frames are obtained. As thumbnail information concerning these frames, information on frame number of the original video frame corresponding each of the thumbnail frames and size of each thumbnail frame are described. Further, scene change information on the original video frames or intra-frame frame change value information are described altogether as additional information, and temporal/spatial thumbnail meta-data is obtained. The meta-data is associated with original video data, and a database is constructed. Then, the meta-data is employed, thereby performing typical frame display of original video data or variable speed reproduction. In this manner, even with a device with its low CPU capability, typical frame display or variable speed reproduction is performed for compressed and encoded video data such as MPEG-2, and the contents of video is checked, and retrieval is easily performed.

Abstract: A system for providing information in a document including a computer system with a publication server adapted to access personalized user content preferences and to select and format information in accordance with the preferences; a printer for receiving the formatted information from the publication server and printing the information in a document with at least one interactive element to enable a user to indicate a response to associated information in the document; and a sensing device used to indicate the response and adapted to transmit response data to the computer system.

Abstract: An optical waveguide module includes a light emitting element which outputs light, a light receiving element which monitors an output of the light emitting element, and an optical waveguide film having a waveguide core which has a notched portion having an optical path changing surface that changes an optical path of part of the light. The light emitting element is coupled to an end portion of the optical waveguide film, and the light receiving element is provided to face a position of the optical waveguide film from where the part of the light whose optical path has been changed by the optical path changing surface exits.

Abstract: Traveling-wave optoelectronic wavelength conversion is provided by a monolithic optoelectronic integrated circuit that includes an interconnected traveling-wave photodetector and traveling-wave optical modulator with a widely tunable laser source. Either parallel and series connections between the photodetector and modulator may be used. An input signal modulated onto a first optical wavelength develops a traveling wave voltage on transmission line electrodes of the traveling-wave photodetector, and this voltage is coupled via an interconnecting transmission line of the same characteristic impedance to transmission line electrodes of the traveling-wave optical modulator to modulate the signal onto a second optical wavelength derived from the tunable laser. The traveling wave voltage is terminated in a load resistor having the same characteristic impedance as the photodetector and modulator transmission lines.

Abstract: The present invention provides a highly-integrated and compact optical element and further provides an optical element having various functions such as lower driving voltage, chirping suppression and polarization-independency. The optical element comprising a substrate 1 consisting of a material having an electrooptic effect, top optical waveguides 2-1 an 2-2 formed on the top face of said substrate, bottom optical waveguides formed on the bottom face of said substrate, a top modulating electrode for controlling the phase of a light wave being propagated through said top optical waveguide, and a bottom modulating electrode for controlling the phase of a light wave being propagated through said bottom optical waveguide, is characterized in that at least one side edge of said substrate comprises output and input of said optical waveguides formed on said top and bottom faces, and a turnback element is located adjacent to said one side edge to guide the light wave from said output to said input.

Abstract: A method and apparatus that includes a first waveguide segment that differentially changes the amplitude of the light relative to a first polarization orientation, a thickness of oriented liquid crystal or other birefringent material sufficient to delay one polarization component one-half wavelength relative to another, and a second waveguide segment that also differentially changes the amplitude of the light based on the polarization orientation. Also, an apparatus that includes a thin polarization converter that includes a thin first substrate that is substantially transparent to a wavelength of light, and a birefringent material deposited on one or more surfaces of the first substrate and oriented such that the polarization converter forms a half-wavelength birefringent plate for the light. Also, an apparatus having a first substrate surface, a second substrate surface, and a liquid crystal material between the first and second substrate surfaces to form a polarization converter.

Abstract: Extensometer with flexible test specimen and Bragg gratings applied in particular to the monitoring of concrete structures, is configured to measure deformations of a host material and comprises at least one test specimen which undergoes linear bending stresses, and at least one Bragg grating formed in an optic fibre and fixed to the test specimen. The extensometer configured such that any deformation of the host material is transmitted to the grating via the test specimen. The extensometer also comprises mechanical means which transform deformation of the material into bending of the test specimen, which deforms the grating.

Abstract: An optical device comprising a first substrate in which V-grooves are made, four optical fibers, for example, having a reflective function and fixed in the V-grooves of the first substrate, an optical element bonded, through an adhesive layer, onto the optical path of a reflected light at least generated by the reflective function on the outside of the clad of each optical fiber, and a second substrate for mounting the optical element, wherein the second substrate is disposed such that the mounting surface of the optical element faces the first substrate.

Abstract: A colorless, waveguide-grating-router-based tunable dispersion compensator includes a planar lightwave circuit and a deformable mirror, optically coupled to each other by a plano-cylindrical glass lens such that a fast tuning speed and single-knob dispersion adjustment are obtained. In a further aspect of the present invention, the waveguide-grating router is pinched, symmetrical about its center line, and has a half-wave plate inserted therein to provide polarization independence. In a still further aspect of the present invention, the deformable mirror includes, reflective film attached to opposing piezo-electric actuators.

Abstract: In a method and apparatus for converting optical wavelength division multiplexed channels to wireless channels, the information carrying optical carriers are first de-multiplexed and each optical carrier is then extracted from the data using an optical channelizing technique. The optical frequency of each of the extracted optical carriers is then shifted by an amount equal to the desired wireless carrier frequencies in the broadband wireless channels. Optical heterodyning of the frequency-shifted extracted lightwave carriers with the original data-containing optical signals, which are mutually in phase coherence, in a photodetector results in a set of wireless carriers each modulated with the data carried by the corresponding optical channel.

Abstract: An optical switching fabric with an optical to electrical converter in the output plane. The optical switching fabric has an input plane with at least one input. The input plane provides at least a first optical signal (e.g., a first set of optical signals). The optical switching fabric has an output plane. The optical switching fabric has an interconnection mechanism for receiving the first set of optical signals and directing each received optical signal to a predetermined location in the output plane. The output plane has at least one optical to electrical converter (e.g., a plurality of optical to electrical converters) for receiving the directed optical signals and responsive thereto for generating a set of corresponding electronic output signals.

Abstract: A method and an apparatus to provide optical equipment protection have been disclosed. In one embodiment, the method includes diverting a predetermined portion of each of a plurality of optical signals to a plurality of photonic detectors within a first optical network node, and detecting the plurality of signals using the plurality of photonic detectors, each of the plurality of photonic detectors being designated to detect one of the plurality of optical signals. Other embodiments have been claimed and described.

Abstract: The subject invention pertains to a method and apparatus for multiplexing in optical fiber communications. The subject invention relates to a method and apparatus for spatial domain modulation in optical wavelengths. In a specific embodiment, the subject invention relates to a spatial domain multiplexer (SDM) for use with an optical fiber. Preferably, the input channels coupled into the fiber optic cable include collimated laser beams. The techniques of the subject invention can be utilized with single mode and multi mode waveguide structures, for example, single mode and multi mode optical fibers. The subject invention is applicable to step index optical fiber and to graded index optical fiber. Applications of the subject technology can include secure data links, for example, which can modulate data such that if the data is intercepted, the data cannot be interpreted. The subject methods and apparatus can also be used in conjunction with other multiplexing techniques such as time-domain multiplexing.

Abstract: The present invention relates to a semiconductor based parabolic waveguide-type collimating lens and a monolithically integrated type tunable external cavity laser diode light source.

Abstract: A multiplexed optical communication system includes a plurality of chopping modulators associated with a first plurality of channels to receive input optical pulses having a first width and to produce therefrom chopped optical pulses having a second width narrower than the first width; a multiplexer to multiplex the chopped optical pulses of the first plurality of channels into a serial bit stream; an optical medium to transport the serial bit stream; and a demultiplexer to demultiplex the serial bit stream into output optical pulses in a second plurality of channels.

Abstract: A light source has a structure in which a 3-dB beam splitter is integrated with a Febry-Perot laser diode having a cleaved plane. A first waveguide grating and a first refractive index modifier changing a Bragg wavelength of the first waveguide grating are provided at one branch of the 3-dB beam splitter. A second waveguide grating and a second refractive index modifier changing a Bragg wavelength of the second waveguide grating are provided at another branch of the 3-dB beam splitter.

Abstract: An arrayed waveguide grating (AWG) device comprising a substrate having a first array of waveguides optically coupled between first and second slab couplers and a second array of input-output waveguides optically coupled at first ends thereof to an input/output side of the second slab-coupler. The input/output waveguide are tapered at first end portions thereof so as to increase in width towards the second slap coupler, and the width (W) of the first ends of the input/output waveguides varies across the second array in a manner so as to increase uniformity of at least on performance parameter, for example adjacent crosstalk (AXT). In the described embodiment, the width (W) of the tapered waveguide ends increases from one side to the array of input/output waveguides to the other, so as to keep the separation(s) between the input/output waveguides.

Abstract: An optical device includes: a silicon substrate; a plurality of silicon oxide columns having a rectangular plan shape; and a cavity disposed between the columns. Each column has a lower portion disposed on the substrate. Each column has a width defined as W1. The cavity has a width defined as W2. A ratio of W1/W2 becomes smaller as it goes to the lower portion of the column. A core layer provided by the columns and the cavity can have the thickness equal to or larger than a few dozen ?m easily. Therefore, connection loss between a light source and the device is reduced.

Abstract: Photonic signals of high bandwidth are input into a winding of optical fiber. The winding of fiber has winds of fiber that are adjacently disposed and that form a substantially linear outer surface of the winding. A series of optical taps are defined in the optical fiber along this surface. The fiber includes an inner core surrounded by an outer layer. The taps comprise a diminished outer layer section of the fiber. It is from these taps that optical energy is released from the fiber.

Abstract: A flexible innerduct structure is configured to contain a cable within a conduit. The innerduct structure includes a pair of adjacent strip-shaped layers of flexible material that are joined along their longitudinal edges to define a channel through which the cable can extend longitudinally through the innerduct structure between the layers. The adjacent layers have differing widths between their longitudinal edges, whereby the wider layer bulges away from the narrower layer to impart an open configuration to the channel. Other features of the innerduct structure relate to the material of which it is formed. Such features includes the structure of the material, such as a woven structure, and further include properties such as melting point, tensile strength, elongation, coefficient of friction, crimp resistance and compression recovery.

Abstract: An electrical conductor and in particular a conductor bar of an electrical machine, particularly a generator or transformer, in which an optical measuring device can be integrally arranged. A measuring unit includes an electrical conductor and an optical measuring device arranged in the conductor, and a production method for producing such an electrical conductor is described. The electrical conductor (10), having a conductor cross section and also an extent in the conductor longitudinal direction, includes a recess (11, 12, 13) in the conductor longitudinal direction at least along a section of the conductor, for integrated arrangement of a signal conductor, in particular an optical waveguide.

Abstract: An optical fiber cable suitable installation using an air-blown method is disclosed. The optical fiber cable has a center tensile member located at a center of the optical fiber cable to provide tension-resistant force, at least three loose tubes each of which includes at least one optical signal transmitting medium, and located to surround a peripheral portion of the center tensile member, a binder surrounding the loose tubes to maintain an alignment pattern of the loose tubes, and a sheath located at an outermost portion of the optical fiber cable. The optical fiber cable has a polygonal sectional shape having smooth edges.

Abstract: An optical fiber for evenly illuminating a target. The optical fiber is coupled to a laser emitting diode and receives laser light. The laser light travels through the fiber optic and exits at an exit end. The exit end has a diffractive optical pattern formed thereon via etching, molding or cutting, to reduce the Gaussian profile present in conventional fiber optic cables. The reduction of the Gaussian provides an even illumination from the fiber optic cable.

Abstract: An optical fiber for transmitting light, said optical fiber having an axial direction and a cross section perpendicular to said axial direction, said optical fiber comprising: (1) a first core region comprising a first core material having a refractive index Nco,1; (2) a microstructured first cladding region surrounding the first core region, said first cladding region comprising a first cladding material and a plurality of spaced apart first cladding features or elements that are elongated in the fiber axial direction and disposed in the first cladding material, said first cladding material having a refractive index Ncl,1 and each said first cladding feature or element having a refractive index being lower than Ncl,1, whereby a resultant geometrical index Nge,cl, 1? of the first cladding region is lowered compared to Ncl,1; (3) a second core region surrounding said first cladding region, said second core region comprising a second core material having a refractive index Nco,2, and (4) a second cladding regio

Abstract: Optical fiber ribbon having an optical fiber with a radiation curable internal coating and a radiation curable colored coating disposed to surround the internal coating, and a radiation curable matrix material surrounding one or more of the optical fibers to form a ribbon, in which: the colored coating has a degree of adhesion to the inner coating which is higher than the degree of adhesion to the matrix material; and the optical fiber in the optical fiber ribbon shows, upon aging of the ribbon for at least two weeks in water at 60° C., an increase in the attenuation of the transmitted signal at 1550 nm of less than 0.05 db/km with respect to the attenuation of the assembled optical fiber measured before aging.

Abstract: The invention concerns a guided wave spatial filter (300) for receiving input radiation and outputting corresponding filtered output radiation, the filter comprising first and second waveguide sections (30, L3, L5) connected in series, the sections: (a) mutually matched for transmitting fundamental mode radiation components present in the input radiation therethrough to provide the output radiation; and (b) mutually mismatched for hindering higher-order mode radiation components present in the input radiation from propagating therethrough and contributing to the output radiation. The spatial filter (300) is implemented using rib waveguides (30) for the sections with associated relatively deeply and relatively shallowly etched structures (20, 310, 320) for imparting to the sections their radiation mode filtration characteristics.

Abstract: An optical waveguide device includes a first substrate, where the first substrate includes a first plate and an optical waveguide region disposed on the first plate, and where the optical waveguide region includes a core for transmitting light and a cladding surrounding the core. The optical waveguide device further includes a second substrate, where the second substrate includes a second plate having a spacer. Additionally, a surface including the optical waveguide region of the first substrate opposes a surface including the spacer of the second substrate, the spacer is formed the region which is out of the core of the first substrate, a top surface of the spacer is in contact with the first substrate, the first substrate and the second substrate are bound with adhesive material, and the entire surface of the core is in contact with the adhesive material.