Abstract: Monochromators selectively transmit a narrow band of wavelengths of radiation from a broader band of wavelengths for use in a variety of applications and industries. Disclosed is a method and system for fixed-exit angle tunable monochromator. The system includes a first diffraction element configured to reflect an input beam incident on a surface of the first diffraction element. The input beam has an input beam vector and the first diffraction element is rotatable about the input beam vector. The system further includes a second diffraction element configured to reflect the beam as an output beam having a fixed beam exit angle. The beam is incident on a surface of the second diffraction element and the reflected beam has a reflected beam vector. The second diffraction element is rotatable about both the input beam vector and the reflected beam vector.

Abstract: In some aspects, a monochromatic x-ray component for producing monochromatic x-ray radiation from broadband x-ray radiation is provided. The monochromatic x-ray component comprises a housing configured to be positioned proximate a broadband x-ray source, at least one first target arranged to receive broadband x-ray radiation emitted from the broadband x-ray source when the housing is positioned proximate the broadband x-ray source, the at least one first target configured to produce first monochromatic x-ray radiation in response to the received broadband x-ray radiation, and at least one second target to receive at least some of the first monochromatic x-ray radiation produced by the at least one first target when the at least one second target is positioned within the monochromatic x-ray component, the at least one second target configured to produce second monochromatic x-ray radiation in response to the received first monochromatic x-ray radiation.

Abstract: A method and system to compensate for stray light errors in time of flight (TOF) camera systems uses reference targets in the in the field of view (FOV) that can be used to measure stray light. In different embodiments, one or more reference targets are used.

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: A system or method for analyzing a sample include an input light source, a double subtractive monochromator positioned to receive light from the input light source and to sequentially illuminate the sample with each of a plurality of wavelengths, a multi-channel fluorescence detector positioned to receive and substantially simultaneously detect multiple wavelengths of light emitted by the sample for each of the plurality of excitation wavelengths, an absorption detector positioned to receive and detect light passing through the sample, and a computer in communication with the monochromator, the fluorescence detector, and the absorption detector, the computer controlling the monochromator to sequentially illuminate the sample with each of the plurality of wavelengths while measuring absorption and fluorescence of the sample based on signals received from the fluorescence and absorption detectors.

Abstract: This invention provides a novel methods and devices for measurement of particle concentration or changes in particle concentration over a wide linear range. The invention comprises one or more radiation sources and one or more detectors contained in a housing which is interfaced to a medium containing particulate matter. The one or more radiation sources are directed into the medium, scattered or transmitted by the particulate matter, and then some portion of the radiation is detected by the one or more detectors. Methods for confining the measurement to a specific volume within the medium are described. Algorithms are provided for combining the signals generated by multiple source-detector pairs in a manner that results in a wide linear range of response to changes in particle concentration. In one embodiment the sensor provides non-invasive measurements of biomass in a bioreactor. In another embodiment an immersible probe design is described, which may be suited for one-time use.

Abstract: An apparatus and a method for optically analyzing a sample are provided. The apparatus includes a first optical device that transmits a narrow waveband of light and has a first filter and a first monochromator that provide different paths for the narrow waveband of the light. The apparatus may also include a light source that generates the light as broadband excitation light, in which case the first optical device transmits a narrow waveband of the broadband excitation light through the first filter or the first monochromator. Further, the apparatus may include a second optical device that directs the narrow waveband of the broadband excitation light onto the sample and receives emission light from the sample, a third optical device that transmits a narrow waveband of the emission light, and a detector that converts the narrow waveband of the emission light into an electrical signal.

Abstract: The invention concerns a measurement system and method for optical spectroscopic measurement of samples. The system comprises an illumination source for forming a primary light beam, a first tunable monochromator for spectrally filtering the primary light beam, a sample-receiving zone to which the spectrally filtered primary beam is directed for producing a secondary light beam affected by a sample in the sample receiving zone, and a second tunable monochromator for spectrally filtering the secondary light beam, and a detector for measuring the intensity of the spectrally filtered secondary beam. In particular, the system is adapted to scan a predefined wavelength range using one of the monochromators and to tune the other monochromator sequentially to one of at least two predefined separate wavelengths in order to eliminate the effect of undesired diffraction orders of the second monochromator on the measurement.

Abstract: A fluorescence spectrophotometer system may be implemented in scanning fluorescence polarization detection applications. A wavelength and area scanning fluorescence spectrophotometer system may include a light source, an excitation double monochromator, an excitation/emission light transfer module, an emission double monochromator, a high speed timer-counter circuit board, a precision positioning apparatus for positioning a sample relative to the focal plane of the excitation light, and polarizing filters at the excitation side and the emission side. The system may be operative to analyze more than one fluorescent compound in the sample; additionally or alternatively, the system enables analysis of samples from selected ones of a plurality of samples.

Abstract: Detected and stored are zero-order light positions which are an angular position of the pre-spectroscope and that of the main spectroscope at which a main light ray incident on the inlet slit reaches the outlet slit via the pre-spectroscope and the main spectroscope. In a state where the main spectroscope is located at its zero-order light position, the pre-spectroscope is rotated to detect the angular position of the pre-spectroscope for a predetermined wavelength. Further, in a state where the pre-spectroscope is located at its zero-order light position, the main spectroscope is rotated to detect the angular position of the main spectroscope for the predetermined wavelength.

Abstract: Inverting optics are used to invert, with respect to the dispersion plane, the wavefront of a monochromator employing a beam making more than one pass through the dispersing medium. Further, the inverting functionality can be turned-on or turned-off, thereby reversibly converting between additive and subtractive monochromator architectures. Inversion reversal is accomplished by reorienting the inverting optics orthogonally about an axis coaxial with the beam, either back and forth or monotonically, or by displacing portions or all of the inverting optics into and out of the beam. Examples of inverting optics include Dove prisms and equivalent multiple all-reflective surfaces. The system and method can be applied to two-pass and other multi-pass monochromators and to dual and other multiple serial monochromator configurations using diffraction gratings or other dispersing elements.

Abstract: A dual-channel, double-filtering, multi-pass OSA having a narrow spectral linewidth response and high ORR comprises a diffraction grating (DG), two input ports (P1?, P1?) for directing first and second input light beams (LR, LT) onto the grating; a retroreflector (RAM1) for returning the dispersed light beams to the grating for dispersion again; two intermediate output ports (P2?, P2?) for receiving the twice-dispersed light beams; two secondary input ports (P3?, P3?) coupled to the intermediate output ports by polarization-maintaining waveguides (PMF2?, PMF2?) for directing the light beams onto the grating a third time, with their SOPs having a predetermined orientation relative to the SOPs of the first and second light beams when first incident upon the grating, the retroreflector (RAM1) returning the three-times-dispersed light beams to the grating for dispersion a fourth time; and two output ports (P4?, P4?) for receiving the light beams after dispersion the fourth time.

Abstract: Inverting optics are used to invert, with respect to the dispersion plane, the wavefront of a monochromator employing a beam making more than one pass through the dispersing medium. Further, the inverting functionality can be turned-on or turned-off, thereby reversibly converting between additive and subtractive monochromator architectures. Inversion reversal is accomplished by rotating the inverting optics by 90 degrees coaxially with the beam, either back and forth or monotonically, or by translating portions or all of the inverting optics into and out of the beam. Examples of inverting optics include Dove prisms and equivalent multiple all-reflective surfaces. The system and method can be applied to two-pass and other multi-pass monochromators and to dual and other multiple serial monochromator configurations using diffraction gratings or other dispersing elements.

Abstract: A depolarizing plate comprising a first rectangular wedge plate that has a first crystallographic optical axis in a diagonal direction of the rectangle and which has a thickness thereof in a vertical direction vary continuously in a direction 45 degrees from said first crystallographic optical axis and a second rectangular wedge plate that has a second crystallographic optical axis in a diagonal direction of the rectangle crossing said first crystallographic optical axis at right angles and which has a thickness thereof in a vertical direction vary continuously in a direction 45 degrees from said second crystallographic optical axis, the two wedge plates being joined in such a position that said first crystallographic optical axis crosses said second crystallographic optical axis at right angles, wherein the slope formed by the joint of said wedge plates is rotated about the optical axis of an incident ray of light.

Abstract: A spectrometer, or a spectral instrument using multiple non-interfering optical beam paths and special optical elements. The special optical elements for use with the instrument are used for directing the optical beam and/or altering the form of the beam. The instrument has the potential, depending upon the totality of the optical components incorporated into the instrument, to be a monochromator, a spectroradiometer, a spectrophotometer and a spectral source. The spectral instrument may further be a part of the spectral system. The system may include the spectral instrument, a power module and means for remote control of the instrument. Such remote control may be by use of a personal computer or a control system dedicated to the control, measurement and analysis of the collected information. The multiple non-interfering beam paths are created using specially designed optical elements such as a diffraction grating, a splitter box, a zero back-lash drive system for movement of the grating element.

Abstract: A fluorescence spectrophotometer having an excitation double monochromator, a coaxial excitation/emission light transfer module, and an emission double monochromator. Each monochromator includes a pair of holographic concave gratings mounted to precisely select a desired band of wavelengths from incoming broadband light without using other optical elements, such as mirrors. Selected excitation light is directed into a sample well by a light transfer module that includes a coaxial excitation mirror positioned to direct excitation light directly to the bottom of a well of a multi-well plate. Fluorescence emission light that exits the well opening is collected by a relatively large coaxial emission mirror. The collected emission light is wavelength selected by the emission double monochromator. Selected emission light is detected by a photodetector module.

Abstract: An optical spectrum analyzer of novel design, in which several different spectra can be measured and analyzed simultaneously. A measuring signal is used as a reference signal for calibrating the optical spectrum analyzer. The light rays are admitted via a coupling device with several coupling apertures arranged in a line; and via a separate decoupling device comprising respective decoupling apertures arranged in a line, the light rays are decoupled. Height offset is realized by a 90° deviation prism. The arrangement makes possible simultaneous analysis of several optical lines with little retroreflection as well as uninterrupted calibration of the measuring process.

Abstract: The invention provides a method and apparatus for determining the wavelength of a sample source of light, the apparatus having a reference light source of known wavelength, a collimator for collimating light from the sample source and from the reference source, a dispersing means for receiving and spatially dispersing collimated light from the collimator according to wavelength, focusing means for focusing dispersed light from the dispersing means, and a photodetector located in the focal plane of the focusing means and having an aperture for spatially selectively admitting light from the focusing means, and operable to provide a temporally calibratable output signal indicative of the wavelength of the selectively admitted light, wherein the apparatus is operable to scan the focused spatially dispersed beam across the aperture, and the photodetector output includes resolvable features corresponding to light from the reference source and sample source, whereby a time difference between the features is indicati

Abstract: An optical filter is provided in the form of a subtractive double monochromator. In each dispersive stage, a concave mirror focuses light between a diffraction grating and a transfer mirror between the stages. Light which misses the transfer mirror is rejected. To reduce aberrations over a wide bandwidth, the radius of curvature R of the mirror is centered on the grating and the transfer mirror has a radius of curvature R/2 and is located midway between the mirror and the grating. The mirror 34 thus coincides with the locus of the focus of the spectral image in both stages.

Abstract: A fluorescence spectrophotometer having an excitation double monochromator, a coaxial excitation/emission light transfer module, and an emission double monochromator. Each monochromator includes a pair of holographic concave gratings mounted to precisely select a desired band of wavelengths from incoming broadband light without using other optical elements, such as mirrors. Selected excitation light is directed into a sample well by a light transfer module that includes a coaxial excitation mirror positioned to direct excitation light directly to the bottom of a well of a multi-well plate. Fluorescence emission light that exits the well opening is collected by a relatively large coaxial emission mirror. The collected emission light is wavelength selected by the emission double monochromator. Selected emission light is detected by a photodetector module.

Abstract: A spectrometer measures a spectrum of a light beam supplied from a light source so as to obtain fine information and coarse information of the spectrum easily. This spectrometer has a holographic grating, an Echelle grating, a rotation stage and a line sensor. In the case where a single pass beam is to be detected, a control processing unit controls the rotation stage so as to rotate the Echelle grating from the Littrow arrangement by a predetermined angle &dgr;1. On the other hand, in the case where a double pass beam is to be detected, the control processing unit controls the rotation stage so as to rotate the Echelle grating from the Littrow arrangement by a predetermined angle &dgr;2.

Abstract: A high resolution etalon-grating spectrometer. A preferred embodiment presents an extremely narrow slit function in the ultraviolet range and is very useful for measuring bandwidth of narrow band excimer lasers used for integrated circuit lithography. Light from the laser is focused into a diffuser and the diffused light exiting the diffuser illuminates an etalon. A portion of its light exiting the etalon is collected and directed into a slit positioned at a fringe pattern of the etalon. Light passing through the slit is collimated and the collimated light illuminates a grating positioned in an approximately Littrow configuration which disburses the light according to wavelength. A portion of the dispursed light representing the wavelength corresponding to the selected etalon fringe is passed through a second slit and monitored by a light detector. When the etalon and the grating are tuned to the same precise wavelength a slit function is defined which is extremely narrow such as about 0.

Abstract: A spectrograph with a first concave spectrographic diffraction grating is positioned to receive light from the input light source is configured to provide a diffracted light output dispersing the components of the input light source in a first direction. The dispersion forms the input light into an intermediate spectra. The intermediate spectra is formed in a focal surface by the once diffracted light. A slit is substantially positioned on the focal surface. A second concave diffraction grating is positioned to receive once diffracted light from the slit and configured to provide a twice diffracted light output, the second concave diffraction grating dispersing the components of the input light source in a second direction. The second direction is different from the first direction, the dispersion forming the input light into an output spectra.

Abstract: A depolarizing plate comprising a first rectangular wedge plate that has a first crystallographic optical axis in a diagonal direction of the rectangle and which has a thickness thereof in a vertical direction vary continuously in a direction 45 degrees from said first crystallographic optical axis and a second rectangular wedge plate that has a second crystallographic optical axis in a diagonal direction of the rectangle crossing said first crystallographic optical axis at right angles and which has a thickness thereof in a vertical direction vary continuously in a direction 45 degrees from said second crystallographic optical axis, the two wedge plates being joined in such a position that said first crystallographic optical axis crosses said second crystallographic optical axis at right angles, wherein the slope formed by the joint of said wedge plates is rotated about the optical axis of an incident ray of light.

Abstract: The monochromator and the spectrometric method are disclosed wherein the measured beam converted into a parallel beam by a first collimator is diffracted by a plane diffraction grating, then the diffracted beam is returned so that the diffracted beam after the return is separated from that before the return along rulings of the plane diffraction grating, the diffracted beam is diffracted again by the plane diffraction grating, then the beam condensed by a second collimator is allowed to pass through an exit slit.

Abstract: A spectrometer, or a spectral instrument using multiple non-interfering optical beam paths and special optical elements. The special optical elements for use with the instrument are used for directing the optical beam and/or altering the form of the beam. The instrument has the potential, depending upon the totality of the optical components incorporated into the instrument, to be a monochromator, a spectroradiometer, a spectrophotometer and a spectral source. The spectral instrument may further be a part of the spectral system. The system may include the spectral instrument, a power module and means for remote control of the instrument. Such remote control may be by use of a personal computer or a control system dedicated to the control, measurement and analysis of the collected information. The multiple non-interfering beam paths are created using specially designed optical elements such as a diffraction grating, a splitter box, a zero back-lash drive system for movement of the grating element.

Abstract: An optical spectrum analyzer comprises a diffraction grating (DG), a polarization decomposing unit (PDM) for decomposing the input light beam into first and second light beams having mutually-perpendicular linear states of polarization, and two output ports (FP2/1, FP2/2) each for receiving from the grating, substantially exclusively, a respective one of the polarized light beams (LT, LR) after diffraction by the diffraction grating (DG).

Abstract: Device and method are described for measuring transmissivity and haze in transparencies as detected through night vision goggles, including an emitter portion and a sensor portion, the emitter portion including a first light source for presenting an image to the sensor portion through the transparency and a second light source for projecting a haze producing light onto the transparency, the sensor portion including a light intensifier tube and a photometer for measuring the luminance output of the light intensifier tube and quantifying attenuation (transmissivity) and haze (light scatter) characteristics of the transparency as viewed through night vision goggles.

Abstract: The present invention refers to a spectrometer device comprising a monochromator means, a light-measuring means receiving light from said monochromator means, and a calibration means comprising a calibration light source. The present invention provides a new spectrometer device whose light-measuring means comprises a plurality of light-measuring elements in an array extending in the direction of dispersion of the monochromator means, and whose calibration means carries out, on the basis of a spectral light measurement with the aid of the calibration light source, an association between the light-measuring elements and the wavelengths of the spectral light which is adapted to be detected by the respective light-measuring elements. These measures substantially facilitate the calibration and especially the automatic execution of said calibration, if desired simultaneously with a spectra measurement, and they improve the accuracy of the calibration.

Abstract: Incoming light is reflected by a first parabolic mirror for incidence as parallel rays of light on a diffraction grating, the reflected light therefrom is incident on a second parabolic mirror, and the reflected light therefrom is bent by first and second reflecting mirror in a vertical direction and reflected back to the second parabolic mirror, from which it is reflected to the diffraction grating. The reflected light from the grating is reflected again by the first parabolic mirror for incidence on a photodetector. An optical glass plate is inserted in the optical path between the second reflecting mirror and the second parabolic mirror. By the passage through the optical glass plate, the optical axis in a horizontal plane is displaced to ensure the incidence of light from the first parabolic mirror on the photodetector regardless of the wavelength of the incoming light to be measured.

Abstract: A spectrometer comprises a tunable interferometer for producing a monochromatic continuous image at an image plane and including two mirrors having substantially parallel surfaces and an adjustable spacing therebetween, a radiation detector located at the image plane for recording the image, a filter arrangement for allowing at least one predetermined range of wavelengths to pass to the detector, and a lens arrangement for collecting radiation and limiting radiation incident on the interferometer to an angle which is substantially perpendicular to the substantially parallel surfaces of the two mirrors.

Abstract: The present invention is a scanning monochromator for producing a light beam which rapidly and repetitively varies in wavelength. The device is a subtractive double monochromator in which an intermediate slit is moved to effect wavelength scanning; the intermediate slit fitted in a rotating disk positioned at the intermediate focal plane of the monochromator. Two forms of the device are disclosed.

Abstract: A double pass scanning monochromator for use in an optical spectrum analyzer includes an input optical fiber for emitting an input light beam, a diffraction grating for diffracting the input light beam to produce a spatially dispersed light beam, a slit for passing a selected portion of the dispersed light beam, a motor for rotating the diffraction grating, a shaft angle encoder for sensing grating position, and an output optical fiber. The light that passes through the slit is directed to the diffraction grating and is recombined by the diffraction grating to produce an output light beam. The light beam to be analyzed is incident on the diffraction grating during first and second passes. A polarization rotation device rotates the polarization components of the light beam by 90.degree. between the first and second passes so that the output of the monochromator is independent of the polarization of the input light beam.

Abstract: A precision slit of adjustable width in which each slit jaw is guided via at least two guide parallelograms lying opposite each other and in which a single setting member acting jointly on the guide parallelograms of one side and displaceable perpendicular to the direction of movement of the slit jaws is provided for the setting of slit width. In a preferred embodiment, the guide parallelograms are developed as spring parallelograms, an embodiment prepared monolithically from a plate of compliant material and having particular advantages.

Abstract: A double monochromator comprises an inlet slit 20, which is imaged in the plane of an intermediate slit 34 through a first grating monochromator 36. The intermediate slit 34 is imaged in the plane of the outlet slit 34 through a second grating monochromator 58 identical with the first grating monochromator 36. Deflecting mirrors 64 and 66 can be moved into the path of rays to enable such a double monochromator to be optionally used as a single monochromator with increased light flux. An additional slit is arranged between the deflecting mirrors 64 and 66. The arrangement is such so that essentially identical beam geometries result at the outlet in both of the operation modes.

Abstract: A double spectrograph system is disclosed. An entrance slit receives and passes light to be analyzed. A first focusing diffraction grating receives that light. A second focusing diffraction grating receives light reflected by the first focusing diffraction grating. The first and second focusing diffraction gratings both have the characteristic of forming planar substantially anastigmatic spectra. Mounting means keeps the first and second gratings at positions symmetrical about an imaginary plane and with their respective focal planes substantially coincident with each other and the imaginary plane. An exit slit receives the light after it has been reflected by the first grating to the second grating and from the second grating to the exit slit.

Abstract: A spectrophotometer having functions of both of a double-monochromator and a single-monochromator including a light source, a first spectroscope having a first slit through which light from the light source passes and a first dispersion element for dispersing the light from the first slit, a second spectroscope having a second slit for receiving light dispersed from the first dispersion element for dispersing the light from the second slit, and a third slit for receiving the light dispersed from the second dispersion element. A sample compartment is provided for transmitting the light from the first dispersion element or from the third slit directly to a detector or through a sample to the detector. An optical unit is provided for changing transmitting light paths between a first light path for transmitting the light from the first dispersion element to the sample compartment through a fourth slit and a second light path for transmitting the light from the third slit to the sample compartment.

Abstract: An improved Raman spectrometer device is provided which provides useful spectral information in situations where Raman spectroscopy has heretofore been unworkable. The spectrometer of the invention makes use of a stationary electrooptical masking device in lieu of conventional slit scanning optics, with the mask being computer controlled to provide a multiplexing function, typically employing Hadamard mathematics. The stationary encoding mask permits use of a relatively inexpensive photodiode detector, as compared with photomultiplier tubes conventionally used in Raman instrumentation. Advantageously, unwanted Rayleigh scattered radiation can be completely eliminated, either by blanking those zones of the mask receiving such radiation, or physically locating the device in such orientation that the Rayleigh scattered radiation does not pass through operative portions of the mask.

Abstract: A spectroscope apparatus includes means for separating light from an object to be measured into spectral components, means for mixing that part of the spectral components which exists in a desired wavelength range, and means for forming an image of the to-be-measured body of mixed light. The image thus obtained is very useful for observing the state of a combustion flame, the progress of photochemical reaction, the progress of biochemical reaction, a desired tissue in a cell, and the state of a flame for analyzing a solution which contains a metal ion, by flame spectrophotometery, that is, provides accurate information and makes possible a precise control operation.

Abstract: An imaging spectrometer device is disclosed useful for providing a dispersed image of the earth's surface (useful in botanical, geographical, geological, and hydrological scientific studies) from a flying platform. In accordance with this invention, a spectrometer device is provided which can be attached to an existing optical telescope. The spectrometer provides a planar focal plane image which can be processed in a number of manners, for example, by using an array of photosensitive elements. In accordance with the principal feature of this invention, the spectrometer includes an optical system wherein light rays are directed through prisms as they pass through the two symmetrical "legs" of the spectrometer. The spectrometer employs a reflecting concave mirror and prism assemblies having parallel entrance and exit surfaces. In accordance with a first embodiment, a single prism assembly is employed whereas the second described embodiment uses a pair of generally identical prism assemblies.

Abstract: A computer controlled optical system for automatically acquiring and storing spectral radiance data for a multiplicity of targets. Several measurement modes are available for each target ranging from a single wavelength measurement to measurement over a plurality of discrete wavelengths. Stepping motive means prompted by computer instructions direct the apparatus to a given set of target coordinates.

Abstract: A monochromator, capable of functioning as either a single monochromator or a double monochromator by positioning of either reflective means or dispersion means in the optical path. Both the reflective means and the dispersion means are placed on a rotary bed which may be rotated by rotary drive means so that one of the above-mentioned optical means may be placed in the optical path, whereby the monochromator functions optimally, depending on the object to be measured.

Abstract: The invention relates to an apparatus for carrying out spectral analysis which is provided with diffraction grating means (1-6, 12-15) for dispersing the incident radiation (3). In order to achieve a high spectral resolution in an economically advantageous manner, the diffraction grating means comprises a plurality of grating surfaces (1-6, 12-15) which are arranged so that the radiation (3), after diffraction from the first grating surface (1, 12), is subject to diffraction also in the other grating surfaces (2-6, 13-15). The grating surfaces hereby have such an orientation that the wavelength dispersion at diffraction from one grating surface acts to increase the wavelength dispersion at diffraction from the following grating surfaces.

Abstract: An optical arrangement for use in spectrometry uses a masking device which eliminates unwanted spectral regions prior to optically resolving the unmasked information. The optical arrangement comprises an entrance slit to select incidence spectral energy from an energized source and a concave grating of relatively low dispersion to image the spectrum of the entrance slit onto a stationary mask which simultaneously selects spectral regions of the dispersed incident spectral energy. The selected spectral regions are collimated and recombined and directed onto an Echelle grating to disperse with high resolution the selected spectral regions. A concave mirror focuses the dispersed selected spectral regions into a focal plane of highly resolved spectral energy which can be detected to determine the spectral information coming from the source. The optical arrangement is particularly well suited for use with narrow spectral bandwidth spectral information distributed over a large spectral range.

Abstract: A perfected laser nephelometer, characterized in that the measuring cell is comprised of a capillary tube (3) of which the inner diameter is close to the diameter of the laser beam (2).

Abstract: A dispersive optical device for use such as a polarizer, spectroscope, monochromator or the like for utilization as a basic component for a monochromator, polarizer, spectroscope, spectrophotometer or the like, includes a dispersive optical member comprising a first and a second grating (3,4) planar parallel applied on a substrate, preferably reflection gratings with the same grating frequency, said gratings, (3,4) being applied with parallel grating rulings, whereby light defracted by the first grating is arranged to strike the second grating (4). The first grating (3) defines the element's input and the second grating (4) defines the element's output.

Abstract: A monochromator comprises a first and a second concave grating. An entrance slit is imaged by the concave grating in the plane as a spectrum. A disc comprises a spiral slot. A section of the slot forms an intermediate slit periodically sweeping transversely across the spectrum. A concave mirror images the fanning point of the concave grating. Thereby the fanned beams are recombined to a single beam. An exit slit is located in an image plane in which an image of the entrance slit is generated. The spectrum can be scanned quickly and cyclically without the gratings having to be rotated. There is also the effect of a double monochromator. Another embodiment comprises two concave mirrors to generate the image.

Abstract: A double monochrometer comprises a main monochrometer including a plane grating and an auxiliary monochrometer including a concave grating. The concave grating is disposed on the entrance or exit optical axis of the main monochrometer. Preferably, the angular dispersion of the concave grating is selected to be smaller than that of the plane grating. Sine bars for rotating the concave and plane gratings for wavelength scanning can be driven by means of a single feed screw mechanism even if the lengths of the sine bars are made different from each other in accordance with a difference in angular dispersion between the concave and plane gratings.

Abstract: In a spectrophotometer for measuring transmission spectra, the holder with a test sample is disposed inside the double monochromator between the intermediate slit and the second dispersive element and is capable of moving across the propagation path of the light flux at the output of the intermediate slit for placing the test sample in the path of the light flux and removing the sample from the path of the light flux.

Abstract: In a double grating monochromator, the scanner comprises a programming device specifying the angular positions of the diffraction gratings, as the radiation spectrum is scanned, so that the angles of radiation incident thereon are related by ##EQU1## where .sigma..sub.1, .alpha..sub.1, and .beta..sub.1 are: constant of one of the diffraction gratings, angle of radiation incident on this grating, and angle of radiation diffracted from this grating, respectively; .sigma..sub.2, .alpha..sub.2, and .beta..sub.2 are: constant of the other diffraction grating, angle of radiation incident on this grating, and angle of radiation diffracted from this grating, respectively; and "K" is spectral order of radiation diffracted from one of the diffraction gratings and extracted by this slit positioned immediately after this grating, the value of "K" being determined by the working portion of the monochromator spectrum.