Abstract: In a spectroscopy module 1, a light passing hole 50 through which a light L1 advancing to a spectroscopic portion 4 passes is formed in a light detecting element 5. Therefore, it is possible to prevent the relative positional relationship between the light passing hole 50 and a light detecting portion 5a of the light detecting element 5 from deviating. Moreover, the light detecting element 5 is bonded to a front plane 2a of a substrate 2 with an optical resin adhesive 63. Thus, it is possible to reduce a stress generated onto the light detecting element 5 due to a thermal expansion difference between the light detecting element 5 and the substrate 2. Additionally, the light transmissive plate 16 covers a part of a light incident opening 50a. Thus, a light incident side surface 63a of the optical resin adhesive 63 becomes a substantially flat plane in the light passing hole 50. Therefore, it is possible to make the light L1 appropriately incident into the substrate 2.

Abstract: An optical spectrum analyzer is implemented with a detector combined with a tunable filter mounted on a stage capable of 360-degree rotation at a constant velocity. Because of the constant rate of angular change, different portions of the input spectrum are detected at each increment of time as a function of filter position, which can be easily measured with an encoder for synchronization purposes. The unidirectional motion of the mirror permits operation at very high speeds with great mechanical reliability. The same improvements may be obtained using a diffraction grating or a prism, in which case the detector or an intervening mirror may be rotated instead of the grating or prism.

Abstract: Alignment marks 12a, 12b, 12c, and 12d are formed on the flat plane 11a of the peripheral edge portion 11 formed integrally with the diffracting layer 8, and when the lens portion 7 is mounted onto the substrate 2, these alignment marks 12a, 12b, 12c and 12d are positioned to the substrate 2, thereby making exact alignment of the diffracting layer 8 with respect to the light detecting portion 4a of the light detecting element 4, for example, not by depending on a difference in curvature radius of the lens portion 7. In particular, the alignment marks 12a, 12b, 12c and 12d are formed on the flat plane 11a, thereby image recognition is given to exactly detect positions of the alignment marks 12a, 12b, 12c and 12d, thus making it possible to make exact alignment.

Abstract: Optical reader systems and methods for label-independent reading of resonant waveguide (RWG) biosensors operably supported by a microplate as defined herein. The system includes a light source, a spectrometer unit, a beam-forming optical system and a scanning optical system that includes a scanning mirror device, a mirror device driver operably coupled to the scanning mirror device, and an F-theta lens arranged between the microplate and the beam-forming optical system. Some systems use multiple optical beams to scan multiple biosensors at once without having to move the microplate. Asynchronous scanning of multiple beams allows for reducing the number of spectrometer units needed.

Abstract: A spectrometer capable of eliminating side-tail effects includes a body and an input section, a diffraction grating, an image sensor unit and a wave-guiding device, which are mounted in the body. The input section receives a first optical signal and outputs a second optical signal travelling along a first light path. The diffraction grating receives the second optical signal and separates the second optical signal into a plurality of spectrum components, including a specific spectrum component travelling along a second light path. The image sensor unit receives the specific spectrum component. The wave-guiding device includes first and second reflective surfaces opposite to each other and limits the first light path and the second light path between them to guide the second optical signal and the specific spectrum component. The first and second reflective surfaces are separated from a light receiving surface of the image sensor unit by a predetermined gap.

Abstract: A multi-channel array spectrometer combines a spectral measurement system and a reference detector which measures photometric or radiometric qualities. High accuracy photometric or radiometric measurement of a wide dynamic range can be achieved by correcting measurement results of the reference detector with a spectral correction factor. The multi-channel array spectrometer comprises a bandpass filter wheel holding a set of bandpass filters and an open hole. The wheel is placed between an entrance slit and gratings. A test light beam passes through a turret of the bandpass filters. The test light beam can be precisely measured band by band. The spectrometer can also quickly and accurately measure a plurality of test light sources having similar spectral characteristics by using the stray light correction factor.

Abstract: A light amount is increased and an analyzing accuracy can be kept in accordance with an enlargement of a load angle, however, a scattered light tends to be loaded in an analysis accompanying the scattered light and a dynamic range of a concentration which can be measured becomes narrow. A light is dispersed by a light dispersing portion, a load angle of the received light is changed per wavelength, the load angle is made larger in the light of a wavelength having a small light amount, and the load angle is made smaller in the light a wavelength having a large light amount and used for an analysis accompanying a scattered light. Accordingly, it is possible to gain a dynamic range of a concentration which can be measured in the analysis accompanying the scattered light, while increasing the light amount and maintaining the analyzing accuracy.

Abstract: The spectroscopic instrument includes a plurality of first lenses arranged one-dimensionally or two-dimensionally; an aperture opening provided near a focal plane of each of the plurality of first lenses; a spectroscopic unit that spectrally distribute the light that has passed through the aperture opening; and a light receiving unit that receives the light spectrally distributed by the spectroscopic unit. The image producing device includes: the spectroscopic instrument; an imaging unit that captures an image formed by an imaging optical system; and an image processing unit that acquires a lighting condition from a result of spectroscopy by the spectroscopic instrument and performs color conversion processing depending on the lighting condition on an image captured by the imaging unit.

Abstract: The present disclosure provides a method and system for focusing, which modulates a broadband light into a dispersive light having a higher dispersion characteristic and a lower dispersion characteristic, and the dispersion light is projected onto an object so as to form an object light. By means of the filtering and dividing procedure, a first optical spectrum of the dispersion light with respect to the higher dispersion characteristic is utilized to detect a height information of the surface profile of the object. Then, according to the height information, a second optical spectrum of the dispersion light with respect to the lower dispersion characteristic is adjusted to focus onto the object so that an imaging sensing device is capable of sensing the object light with respect to the lower dispersion characteristic, and thereby obtaining a clear and focusing image corresponding to the surface of the object.

Abstract: A spectrometer 1, in which a spectroscopic unit 3 spectrally resolves and reflects light L1 having entered the inside of a package 2 while a photodetector 4 detects reflected light L2, comprises a package 2 accommodating the photodetector 4 therein. The package 2 has a semispherical recess 10, while the recess 10 has a bottom face formed with an area 12 having a plurality of grating grooves 14 arranged in a row along a predetermined direction and an area 13 surrounding the area 12. The areas 12 and 13 are continuous with each other and formed on the same curved surface. This can inhibit the grating grooves 14 from shifting their positions even when distortions are generated in the package 2.

Abstract: An optical spectrum analyzer is implemented with a detector combined with a tunable filter mounted on a stage capable of 360-degree rotation at a constant velocity. Because of the constant rate of angular change, different portions of the input spectrum are detected at each increment of time as a function of filter position, which can be easily measured with an encoder for synchronization purposes. The unidirectional motion of the mirror permits operation at very high speeds with great mechanical reliability. The same improvements may be obtained using a diffraction grating or a prism, in which case the detector or an intervening mirror may be rotated instead of the grating or prism.

Abstract: Alignment marks 12a, 12b, 12c, and 12d are formed on the flat plane 11a of the peripheral edge portion 11 formed integrally with the diffracting layer 8, and when the lens portion 7 is mounted onto the substrate 2, these alignment marks 12a, 12b, 12c and 12d are positioned to the substrate 2, thereby making exact alignment of the diffracting layer 8 with respect to the light detecting portion 4a of the light detecting element 4, for example, not by depending on a difference in curvature radius of the lens portion 7. In particular, the alignment marks 12a, 12b, 12c and 12d are formed on the flat plane 11a, thereby image recognition is given to exactly detect positions of the alignment marks 12a, 12b, 12c and 12d, thus making it possible to make exact alignment.

Abstract: Before the diffraction from a diffracting structure on a semiconductor wafer is measured, where necessary, the film thickness and index of refraction of the films underneath the structure are first measured using spectroscopic reflectometry or spectroscopic ellipsometry. A rigorous model is then used to calculate intensity or ellipsometric signatures of the diffracting structure. The diffracting structure is then measured using a spectroscopic scatterometer using polarized and broadband radiation to obtain an intensity or ellipsometric signature of the diffracting structure. Such signature is then matched with the signatures in the database to determine the grating shape parameters of the structure.

Abstract: An analysis system, tool, and method for performing downhole fluid analysis, such as within a wellbore. The analysis system, tool, and method provide for a tool including a spectroscope for use in downhole fluid analysis which utilizes an adaptive optical element such as a Micro Mirror Array (MMA) and two distinct light channels and detectors to provide real-time scaling or normalization.

Abstract: To train a machine learning system, a set of different values of one or more photoresist parameters, which characterize behavior of photoresist when the photoresist undergoes processing steps in a wafer application, is obtained. A set of diffraction signals is obtained using the set of different values of the one or more photoresist parameters. The machine learning system is trained using the set of measured diffraction signals as inputs to the machine learning system and the set of different values of the one or more photoresist parameters as expected outputs of the machine learning system.

Abstract: A hyperspectral imaging system has fore-optics including primary, secondary and tertiary fore-optics mirrors, and an imaging spectrometer including primary, secondary and tertiary spectrometer mirrors. Light from a distant object is collected by the primary fore-optics mirror, and the tertiary fore-optics mirror forms an intermediate object image at an entrance side of a spectrometer slit. The spectrometer mirrors are configured so that light from an exit side of the slit is diffracted by a grating on the secondary mirror, and an image representing spectral and spatial components of the object is formed by the tertiary spectrometer mirror on a focal plane array. The surface of each mirror of the fore-optics and the spectrometer has an associated axis of symmetry. The mirrors are aligned so that their associated axes coincide to define a common system axis, thus making the imaging system easier to assemble and align in relation to prior systems.

Abstract: A spectrograph including a primary mirror, a secondary mirror, and a tertiary mirror forming a TMA having a common vertex axis. The spectrograph also may include a collimating mirror, a diffraction grating, and a dispersive prism. The collimating mirror and an entrance aperture form an interchangeable module. Radiation received through the entrance aperture is reflected in a collimated pattern towards an aperture stop. The diffraction grating, located between the collimating mirror and prism, diffracts radiation passed through the aperture stop into multiple beams directed onto the prism. A flat mirror, located to one side of the vertex axis. receives and reflects the multiple beams exiting the prism onto the primary mirror, where they are reflected onto the secondary mirror. The secondary mirror reflects the beams to the tertiary mirror where they are reflected onto an image plane located on the other side of the vertex axis.

Abstract: This application describes a spectrometer that includes a set of collimating optics to collimate received EMR to produce a collimated EMR. The spectrometer also includes a first dispersive optical element for dispersing the collimated EMR and a second dispersive optical element spaced apart from the first dispersive optical element to produce further dispersed EMR. The first dispersive optical element and the second dispersive optical element cooperate to disperse received EMR into a plurality of even frequency spaced EMR spectra. The spectrometer also includes a detector positioned to receive the EMR after passing though an optical path that includes the set of collimating optics, the first dispersive optical element, the second dispersive optical element, and a set of focusing optics.

Abstract: The invention concerns an optical system. The optical system comprises an input for receiving an optical signal, a predetermined output plane, and a diffraction grating for separating the optical signal received at the input into spectral elements thereof. The grating has a diffraction surface, which is formed by a photolithography process. The diffraction surface has a first predetermined profile. The first profile is formed by a plurality of points each conducted by different equations. Consequently, each spectral component is focused on the predetermined output plane.

Abstract: The compact microspectrometer for fluid media has, in a fixed spatial coordination in a housing, a light source, a fluid channel, a reflective diffraction grating, and a detector. The optical measuring path starting from the light source passes through the fluid channel and impinges on the diffraction grating. The spectral light components reflected by the diffraction grating impinge on the detector.

Abstract: A concave diffraction grating device, a reflective dispersion device, and a spectral device of the invention include a diffraction grating plane having an aspherical configuration, wherein the diffraction grating plane is symmetrical in a predetermined direction, and asymmetrical in a direction orthogonal to the predetermined direction in such a manner that the curvature of one end portion of the diffraction grating plane in the direction orthogonal to the predetermined direction is gradually decreased, and the curvature of the other end portion thereof is gradually increased. The concave diffraction grating device, the reflective dispersion device, and the spectral device with the above arrangement have desirable slit image forming performance with respect to all the wavelengths in a visible region, and are suitable for mass-production.

Abstract: A detection system comprising detection processing means, spectral discrimination means, and temporal tracking and declaration processing means which cooperate to detect and declare a missile launch. A spatial filter isolates discrete spectral features in an image from a detector array. The discrete spectral features must pass a threshold, which may be adaptive. In a spectral discrimination step, the pixel-to-pixel separation for those pixels passing the spatial filter step is compared to a predetermined pixel spacing. The predetermined pixel spacing is determined from the optical setup and a spectral feature of interest that is contained within the emission from, for example, an ignited rocket motor or other fired projectile. In a temporal step, the pixels that have met the other criteria are tracked as candidate detections, which are declared a threat if they display characteristics of a moving threat, e.g., a MANPADS missile, RPG, mortar or the like.

Abstract: The present invention provides a small spectroscope that has a short response time. A spectroscope according to one embodiment of the present invention includes: a beam deflector that includes an electro-optic crystal, having an electro-optic effect, and paired electrodes used to apply an electric field inside the electro-optic crystal; spectroscopic means for dispersing light output by the beam deflector; and wavelength selection means for selecting light having an arbitrary wavelength from the light dispersed and output by the spectroscopic means.

Abstract: Various embodiments include spectrometers comprising diffraction gratings monolithically integrated with other optical elements. These optical elements may include slits and mirrors. The mirrors and gratings may be curved. In one embodiment, the mirrors are concave and the grating is convex. The mirrors and grating may be concentric or nearly concentric.

Abstract: Computed tomography imaging spectrometers (“CTISs”) employing a single lens are provided. The CTISs may be either transmissive or reflective, and the single lens is either configured to transmit and receive uncollimated light (in transmissive systems), or is configured to reflect and receive uncollimated light (in reflective systems). An exemplary transmissive CTIS includes a focal plane array detector, a single lens configured to transmit and receive uncollimated light, a two-dimensional grating, and a field stop aperture. An exemplary reflective CTIS includes a focal plane array detector, a single mirror configured to reflect and receive uncollimated light, a two-dimensional grating, and a field stop aperture.

Abstract: A planar nanospectrometer formed as a single chip that uses diffraction structures, which are combinations of numerous nano-features placed in a predetermined configuration and providing multiple functionalities such as guiding light, resonantly reflecting light at multiple wavelengths, directing light to detectors, and focusing light on the detectors. The diffraction structure can be described as a digital planar hologram that comprises an optimized combination of overlaid virtual sub-gratings, each of which is resonant to a single wavelength of light. Each device includes at least one sensor, at least one light source, and at least one digital planar hologram in an optical waveguide. The device of the present invention allows detection of small amounts of analytes in gases and liquids or on solid surfaces and can be particularly advantageous for field analysis of environmental safety in multiple locations because of its miniature size and low cost.

Abstract: A concave reflection type diffraction optical element used for a Rowland type spectrometer, in which: the Rowland type spectrometer detects wavelengths in a range including a wavelength ?1 or more and a wavelength ?2 or less (?1<?2); the concave reflection type diffraction optical element has a diffractive efficiency D(?) at a wavelength ? which shows local maximum and maximum value at a wavelength ?a satisfying, ? 1 ? ? a < 7 ? ? 1 + 3 ? ? 2 10 ; the concave reflection type diffraction optical element includes a reference surface having an anamorphic shape; and the following condition is satisfied: R>r, where R indicates a meridional line curvature radius of the reference surface and r indicates a sagittal line curvature radius thereof.

Abstract: A detection system is used during irradiation of an interaction region of a structure with laser light. The structure includes embedded material. The detection system includes means for receiving light emitted from the interaction region. The detection system further includes means for separating the received light into a spectrum of wavelengths. The detection system further includes means for analyzing at least a portion of the spectrum for indications of embedded material within the interaction region.

Abstract: Computed tomography imaging spectrometers (“CTIS”s) having color focal plane array detectors are provided. The color FPA detector may comprise a digital color camera including a digital image sensor, such as a Foveon X3® digital image sensor or a Bayer color filter mosaic. In another embodiment, the CTIS includes a pattern imposed either directly on the object scene being imaged or at the field stop aperture. The use of a color FPA detector and the pattern improves the accuracy of the captured spatial and spectral information.

Abstract: A method to determine and correct broadband background in complex spectra in a simple and automatized manner includes carrying out a background correction with respect to broadband background before a calibration step. The background correction may involve recording a spectral graph and smoothing the recorded spectral graph, determining all values in the initially recorded graph having a value higher than the value of the smoothed graph and reducing such values to the value of the smoothed graph, and repeating these two steps. The background graph obtained is then subtracted from the initial graph. The smoothing of the graph is carried out by moving average, where each intensity value I at the position x in the spectrum is replaced by an average value. The characteristics of the found peaks can be stored in a file so that the calibration can be used at any time.

Abstract: An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

Abstract: Fiber optic sensors employ a high brightness light source such as a fiber optic supercontinuum source, multiplexed superluminescent light emitting diodes, or a broadband tunable laser diode. Light is delivered to the measurement location via fiber optics and sensor optics directs infrared radiation onto material the being monitored that is located in a hostile environment. A disperse element is positioned in the detection beam path in order to separate the wavelengths and to perform spectral analysis. A spectral analysis of the radiation that emerges from the sheet yields information on a plurality of parameters for the material. For papermaking applications, the moisture level, temperature and cellulose content in the paper can be obtained.

Abstract: An analysis apparatus for analyzing a specimen comprises a spectral separator for dispersing spatially an electromagnetic wave introduced from the specimen into spectral components, a sensing element array containing plural sensing elements for sensing the spectral components of the electromagnetic wave dispersed spatially by the spectral separator, and a spectrum calculator for calculating the spectrum from the signal sensed by the sensing elements; the sensing element array having sensitivities different to each of the spectral components of the electromagnetic wave dispersed spatially by the spectral separator, and the spectral separator and the sensing element array being placed so as to receive the spectral components by each of the sensing elements at different incident angles.

Abstract: An optical characterisation system is described for characterising optical material. The system typically comprises a diffractive element (104), a detector (106) and an optical element (102). The optical element (102) thereby typically is adapted for receiving an illumination beam, which may be an illumination response of the material. The optical element (102) typically has a refractive surface for refractively collimating the illumination beam on the diffractive element (104) and a reflective surface for reflecting the diffracted illumination beam on the detector (106). The optical element (102) furthermore is adapted for cooperating with the diffractive element (104) and the detector (106) being positioned at a same side of the optical element (102) opposite to the receiving side for receiving the illumination beam.

Abstract: A system and method processes a structure comprising embedded material. The system includes a laser adapted to generate light and to irradiate an interaction region of the structure. The system further includes an optical system adapted to receive light from the interaction region and to generate a detection signal indicative of the presence of embedded material in the interaction region. The system further includes a controller operatively coupled to the laser and the optical system. The controller is adapted to receive the detection signal and to be responsive to the detection signal by selectively adjusting the laser.

Abstract: A laser induced breakdown spectroscopy (LIBS) system uses discrete optical filters for isolated predetermined spectral components from plasma light created by ablation of a sample. Independent detection elements may be used for detecting the magnitude for each spectral component. A first spectral component may include a characteristic wavelength of the sample, while a second spectral component may be a portion of a background continuum. The filters may include volume Bragg gratings and the detectors may be photodiodes. A detector that detects plasma light remaining after the isolation of the predetermined spectral components may be used together with a signal acquisition controller to precisely control the initiation and termination of signal acquisition from each of the detection elements. The system may also have optics including a collimating lens through which passes both the initial plasma light and the isolated spectral components.

Abstract: In a polychrometer and a method for correcting stray light of the polychrometer, relative spectral (inter-pixel) distribution of stray light independent of a spectral distribution of an incident light is obtained, intensity coefficient of the stray light is calculated according to spectral (inter-pixel) distribution of the incident light, spectral (inter-pixel) distribution of the stray light included in a spectral (inter-pixel) distribution of an incident light is estimated and corrected. Thus, the stray light can be more accurately corrected as compared with a conventional case where stray light distribution is directly estimated from an incident light.

Abstract: A spectral analytical unit for acting on a parallel light bundle having different wavelengths.

Abstract: A scanning optical spectrometer with a detector array is disclosed, in which position of focused spot of light at the input of a dispersive element such as arrayed waveguide grating (AWG) with a slab input, is scanned using a micro-electro-mechanical (MEMS) tiltable micromirror so as to make the dispersed spectrum of light scan over the detector array coupled to the AWG. Sub-spectra recorded using individual detectors are concatenated by a processor unit to obtain the spectrum of input light.

Abstract: An apparatus consisting of two pairs of identical lenses which is suitable as a compound objective lens for high numerical aperture imaging is disclosed. The compound lens also has a wide field of view as a fraction of the compound lens focal length. By suitable choice of lens materials, well corrected near infrared imaging can be achieved. When two such compound lenses together with a diffraction grating are assembled into a spectrometer, excellent wavelength resolution in the near infrared can also be obtained.

Abstract: The present invention relates to a dispersive spectrometer. The spectrometer allows detection of multiple orders of light on a single focal plane array by splitting the orders spatially using a dichroic assembly. A conventional dispersion mechanism such as a defraction grating disperses the light spectrally. As a result, multiple wavelength orders can be imaged on a single focal plane array of limited spectral extent, doubling (or more) the number of spectral channels as compared to a conventional spectrometer. In addition, this is achieved in a common path device.

Abstract: The present invention provides a novel approach for reliably and accurately detecting and identifying airborne particles. This is done by providing a novel system which incorporates electrostatic concentrators and/or ion mobility separators with Raman, IR, UV, XRF, LIF and LIBS spectroscopy and/or other spectroscopic techniques.

Abstract: Objects are to obtain a highly accurate diffraction element that may prevent an intensity decrease of a light beam entering a light receiving unit without a decrease in diffraction efficiency and without a problem of flare or the like, a manufacturing method for the diffraction element, and a spectrometer using the same. A diffraction element (2) includes a diffraction grating formed on a substrate having a curved surface. In the diffraction element (2), the curved surface (3) has an anamorphic shape formed by pivoting a curved line (I) in a plane about a straight line (II) in the same plane serving as a rotation axis, and gratings (10a) of the diffraction grating (10) exist in cross sections orthogonal to the rotation axis.

Abstract: A system and method are provided for imaging a test substrate having a test surface that is configured to enable spectroscopic detection of one or more chemical or biological species, wherein the test surface includes a testing site disposed thereon according to a predetermined spatial pattern. The test substrate is provided in an image plane or a Fourier Transform plane of a sensor. The invention provides high throughput and high spectral resolution.

Abstract: Methods and assemblies are provided for evaluating plants for presence of pests. Methods may include separating pests from a plant to produce a sample of pests for analysis, illuminating the sample to produce emitted light from the sample, and comparing the emitted light from the sample to a model to discriminate pests within the sample. Assemblies may include a separating unit operable to separate pests from a plant to produce a sample comprising pests, a light source for illuminating at least part of the sample, and an imaging device adjacent the light source for receiving light from the illuminated sample and creating an image of the sample.

Abstract: A spectral colorimetric apparatus for detecting a color of an image of a test subject illuminated includes a stop; a spectral detection optical system for spectrally detecting a beam diffused in the test subject and passing through the stop; and a guiding optical system for guiding, toward the stop, the beam diffused in the test subject, wherein in a first section which is a section including an optical axis of the guiding optical system, condensing positions of the light beam condensed by the guiding optical system change depending on a position in a direction orthogonal to the first section, and the stop is disposed between condensing positions closest to and farthest from the guiding optical system, of condensing positions, in the first section, of the beam condensed by the guiding optical system, in a direction of the optical axis of the guiding optical system.

Abstract: The invention generally relates to spectrometers and optical systems useful therein. More particularly, the invention generally relates to optical systems and systems having improved functionalities, flexibilities, and design options. For example, optical systems of the invention employ an aberration-corrected concave grating along with one or more transmissive aberration correctors.

Abstract: A spectral colorimetric apparatus for detecting a color of an image of a subject, including: an illumination optical system illuminating the subject on a detection surface; a spectral optical system including a spectral element spectrally separating the beam diffused by the subject and a light receiving element array detecting a spectral intensity distribution; and a guiding optical system for guiding a beam diffused by the subject, wherein: the detection surface is parallel to a spectral plane including a principal ray of a beam entering the spectral optical system and a principal ray of a beam spectrally separated; the principal ray of the beam enters the spectral optical system within the spectral plane obliquely to a line joining a center of the light receiving element array with a surface vertex of the spectral element; and a light receiving surface of the light receiving element array is orthogonal to the spectral plane.

Abstract: There is provided is a spectrometer having a concave reflection type diffraction element, wherein, among surfaces other than a diffraction surface of the diffraction element, non-diffraction surfaces which are located outside the diffraction surface at the same side as the diffraction surface are a glossy surface, the spectrometer includes a light detection unit which is located at an imaging position of a first-order diffracted light diffracted by the diffraction element to receive the first-order diffracted light, and the light detection unit is disposed inside optical paths of light beams regularly reflected on the non-diffraction surfaces outside the diffraction surface. Accordingly, it is possible to effectively suppress a stray light reflected on the surfaces other the diffraction surface from being incident into the light detection unit and to detect the light spectrally diffracted by the diffraction surface at high accuracy.

Abstract: An instrumentation system utilizes a single light source collimated through windows through a gas line in communication with a fuel cell. As each beam passes through each window, the gas stream will attenuate each beam. A diffraction grating disperses each attenuated beam and transmits particular wavelength bands through a focusing system to a detector. The measured concentration in the gas stream may then be utilized by a controller to determine the amount of power produced by the cell, determine potential leaks, or determine incomplete reaction.