Abstract: A beam-splitting apparatus arranged to receive an input radiation beam and split the input radiation beam into a plurality of output radiation beams. The beam-splitting apparatus comprising a plurality of reflective diffraction gratings arranged to receive a radiation beam and configured to form a diffraction pattern comprising a plurality of diffraction orders, at least some of the reflective diffraction gratings being arranged to receive a 0th diffraction order formed at another of the reflective diffraction gratings. The reflective diffraction gratings are arranged such that the optical path of each output radiation beam includes no more than one instance of a diffraction order which is not a 0th diffraction order.

Abstract: The present invention relates to devices and methods for spectrometric analysis of light-emitting samples. The device comprises a particle beam source, which generates a primary particle beam directed to the sample in such a way that the primary particle beam is incident on the sample and photons are released from the sample due to the interaction between primary particle beam and sample material. Moreover, the device comprises a plurality of light-pickup elements, which are suitable for capturing the photons released from the sample, wherein the light-pickup elements capture the photons emitted in the respectively assigned solid-angle range. Furthermore, the device comprises conduction elements, which are embodied to forward captured photons to an evaluation unit, and an analysis system, which comprises a plurality of evaluation units in such a way that photons captured by each light-pickup element are analyzed spectrally.

Abstract: A hyperspectral imaging system, a monolithic Offner spectrometer, and two methods for manufacturing the monolithic Offner spectrometer are described herein. In one embodiment, the monolithic Offner spectrometer comprises a transmissive material which has: (1) an entrance surface which has an opaque material applied thereto, where the opaque material has a portion removed therefrom which forms a slit; (2) a first surface which has a first reflective coating applied thereto to form a first mirror; (3) a second surface which has a second reflective coating applied thereto to form a diffraction grating; (4) a third surface which has a third reflective coating applied thereto to form a second mirror; and (5) an exit surface.

Abstract: A method of fabricating Fiber Bragg gratings in a micro/nanofiber using ultrashort pulse irradiation, the method includes elongating and flame-brushing a single mode optical fiber to create a micro/nanofiber, and generating the ultrashort pulse irradiation to induce a plurality of refractive index changes at predetermined intervals within the micro/nanofiber, wherein the ultrashort pulse propagates through a focusing element and a diffractive element prior to propagating on the micro/nanofiber.

Abstract: A spectrometer comprising a waveguide module, a diffractive component, and a light sensor is provided. The waveguide module has a first reflective surface, a second reflective surface opposite to the first reflective surface, and a light channel between the first reflective surface and the second reflective surface. The diffractive component has a diffractive surface and a plurality of strip-shaped diffractive structures located on the diffractive surface. The sharpness of the profile of the strip-shaped diffractive structures on a first side of the diffractive surface is greater than that on a second side of the diffractive surface. When viewed along a direction perpendicular to the second reflective surface, the first side of the diffractive surface is positioned between the first reflective surface and the second reflective surface with a distance away from the second reflective surface. A method for assembling the spectrometer and an assembling system are also provided.

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: The apparatus for measuring concentrations of fuel mixtures using depth-resolved laser-induced fluorescence is a fluorometer equipped with a sample container holder that is movable in the path of the beam from the light source. Fluorescent emissions from the sample mixture pass at 90° to the excitation light path through a slit that is narrow enough that the emission intensity is effectively produced by a thin layer of the sample and focused on a monochromator, with successive thin layers receiving nonuniform excitation radiation due to reduction of intensity along the excitation light source path with increasing depth penetration and due to reabsorption of emitted fluorescence from adjacent layers. The method has a first mode in which the emission spectrum is scanned at a fixed depth, and a second mode in which the sample is moved relative to the emission monochromator slit to vary the depth while keeping the emission wavelength fixed.

Abstract: This disclosure describes an aperture shaped to provide a narrow beam in the horizontal plane but a wider beam in the vertical plane that will provide improved image quality in spectrometers.

Abstract: A wavelength selective switch utilizing aperture-shared optics and functionally distinct planes of operation that enables high fiber port counts, such as 1×41, and multiplicative expansion, such as to 1×83 or 1×145, by utilizing elements optimized for performance in one of the functionally distinct planes of operation without affecting the other plane.

Abstract: A device for sorting and concentrating electromagnetic energy impinging a surface of the device, the surface including at least one plasmonics-based surface structure or similar structure of periodic or quasi-periodic surface topography. The device is characterized in that the surface (V) is provided with at least two such surface structures (2), acting as individual concentrator structures, which are at least partially spatially overlapped or superposed.

Abstract: The apparatus for measuring concentrations of fuel mixtures using depth-resolved laser-induced fluorescence is a fluorometer equipped with a sample container holder that is movable in the path of the beam from the light source. Fluorescent emissions from the sample mixture pass at 90° to the excitation light path through a slit that is narrow enough that the emission intensity is effectively produced by a thin layer of the sample and focused on a monochromator, with successive thin layers receiving nonuniform excitation radiation due to reduction of intensity along the excitation light source path with increasing depth penetration and due to reabsorption of emitted fluorescence from adjacent layers. The method has a first mode in which the emission spectrum is scanned at a fixed depth, and a second mode in which the sample is moved relative to the emission monochromator slit to vary the depth while keeping the emission wavelength fixed.

Abstract: Disclosed are an apparatus and a method for analyzing milk in a field, capable of analyzing the quality of milk by rapidly and easily examining components of milk in a field, other than a laboratory. To manage the quality of milk, a monochromator using an interference filter having different wavelength bands is employed to the apparatus for analyzing milk, and the amount of milk samples used at one time is increased, so components of milk are simultaneously examined. The apparatus for analyzing milk has a portable structure, so the components of milk are simply, rapidly and easily determined in the field, and the apparatus for analyzing milk is inexpensive as compared with existing apparatuses, thereby increasing the productivity.

Abstract: A method and system for determining a physical property as a function of position. A data series including data point from one or more channels is obtained by frequency modulation continuous wave. A number of data points correspond to Nda different values of frequency of modulation. One or more processing steps are performed including at least part of said primary data series to obtain at least one secondary data series comprising N (N>Nda) data points from the values of frequency of modulation. The secondary data series from frequency domain is transformed to obtain at least one back scattering curve in space domain, and optionally the back scattering curve(s) to one or more physical properties as a function of position.

Abstract: The apparatus for measuring concentrations of fuel mixtures using depth-resolved laser-induced fluorescence is a fluorometer equipped with a sample container holder that is movable in the path of the beam from the light source. Fluorescent emissions from the sample mixture pass at 90° to the excitation light path through a slit that is narrow enough that the emission intensity is effectively produced by a thin layer of the sample and focused on a monochromator, with successive thin layers receiving nonuniform excitation radiation due to reduction of intensity along the excitation light source path with increasing depth penetration and due to reabsorption of emitted fluorescence from adjacent layers. The method has a first mode in which the emission spectrum is scanned at a fixed depth, and a second mode in which the sample is moved relative to the emission monochromator slit to vary the depth while keeping the emission wavelength fixed.

Abstract: A modular spectroscopy laboratory (MSL), comprises a rigid case with a flashlamp rotatably mounted in said case. A sample holder is provided for holding a sample of solution for analysis, and a spectrometer is optically connected to the sample holder. The flashlamp is positionable at least two angles relative to the sample holder.

Abstract: The present invention relates to a system and methods for acquiring two-dimensional Fourier transform (2D FT) spectra. Overlap of a collinear pulse pair and probe induce a molecular response which is collected by spectral dispersion of the signal modulated probe beam. Simultaneous collection of the molecular response, pulse timing and characteristics permit real time phasing and rapid acquisition of spectra. Full spectra are acquired as a function of pulse pair timings and numerically transformed to achieve the full frequency-frequency spectrum. This method demonstrates the ability to acquire information on molecular dynamics, couplings and structure in a simple apparatus. Multi-dimensional methods can be used for diagnostic and analytical measurements in the biological, biomedical, and chemical fields.

Abstract: A system and process for analyzing a sample includes an excitation section and an analyze section, said excitation section including a light source emitting an incident measurement luminous beam, a polarisation state generator (PSG), first optics, and said analyze section includes a polarisation state analyzer (PSA), a detection system and second optics. The excitation section includes an illumination source emitting an incident visualization luminous beam, superposition optics that direct the incident visualization luminous beam toward the sample surface along an optical axis which is identical to the optical axis of the incident measurement luminous beam and the analyze section includes separation optics that transmit a part of the reflected or transmitted visualization luminous beam and a part of the reflected or transmitted measurement luminous beam towards a visualization direction.

Abstract: A device for sorting and concentrating electromagnetic energy impinging a surface of the device, the surface including at least one plasmonics-based surface structure or similar structure of periodic or quasi-periodic surface topography. The device is characterised in that the surface (V) is provided with at least two such surface structures (2), acting as individual concentrator structures, which are at least partially spatially overlapped or superposed.

Abstract: The invention relates to a monochromator device for selecting at least one wavelength band from incident radiation in a given wavelength range. The monochromator device may include at least one optical layer of a monocrystalline material having a crystallographic line that is adapted to the at least one wavelength band to be selected; and a mechanical substrate. The at least one optical layer and the mechanical substrate are assembled by molecular bonding.

Abstract: Apparatuses and methods for performing spectroscopy and optical microscopy are disclosed. In at least one embodiment, a Raman spectrometer includes a vacuum ultraviolet light source configured to generate light having a wavelength within a window in the vacuum ultraviolet region of the electromagnetic spectrum within which a local minimum in the absorption coefficient of Oxygen occurs. The spectrometer also includes a lens device that receives a first portion of the generated light, directs at least some of the first portion of the generated light toward a target location, receives reflected light from the target location, and directs the reflected light toward a further location. The spectrometer further includes a dispersive device that receives at least some of the reflected light and outputs dispersed light produced based thereupon, and a camera module that is positioned at additional location, where the camera module receives at least some of the dispersed light.

Abstract: Disclosed are high-throughput spectral imaging and spectroscopy apparatus and methods that acquire the property information of measured substance's UV-visible and infrared radiation through using at least one substantially uniform monochromatic incident irradiation source and spatial resolved array detector. The high-throughput analysis is achieved by acquiring a parallel spectral imaging and spectroscopy over a library element substrate. The apparatus and methods include both hardware and software for achieving both spectral imaging and spectroscopic analysis.

Abstract: The present invention relates to methods, apparatus, and imaging systems for using near-infrared spectroscopy imaging of plant embryos for classifying plant embryos. In one embodiment, a method is provided for classifying a plant embryo of an unknown type based on near infrared spectroscopy imaging.

Abstract: Application of digital light processor (DLP) systems in monochromator, spectrophotometer or the like systems to mediate selection of individual wavelengths, and/or to image elected regions of a sample in an imaging ellipsometer, imaging polarimeter, imaging reflectometer, imaging spectrophotometer, and/or to provide chopped beams.

Abstract: A confocal spectrometer provides astigmatic optics which supply a monochromator or spectrograph with the image of a sample, with the astigmatic optics thereby providing separate first and second (tangential and sagittal) focal planes for the image. The monochromator/spectrograph has an entrance slit oriented along one of the focal planes, and this slit defines the spectral resolution of the monochromator/spectrograph and the field of view of the sample in one direction (in one focal plane). A supplemental slit is situated outside the monochromator/spectrograph adjacent the entrance slit, with the supplemental slit being oriented along the other focal plane. The supplemental slit therefore defines the field of view of the sample in a perpendicular direction (in the other focal plane). By varying the width of the supplemental and/or entrance slits, one may easily achieve the desired field of view.

Abstract: An atomic absorption spectrometer is disclosed which includes a monochromater and an optical path defined by a toric mirror, a flat mirror, a flat mirror, a flat mirror, a toric mirror, and a further toric mirror. The toric mirror directs light through entrance slit of the monochromater so that radiation is reflected from diffraction grating and out exit slit to a detector. A sample stage in the form of a furnace is located between the mirrors. The monochromater is oriented so that the entrance slit is arranged transverse to the vertical.

Abstract: The invention provides a sensor including a first sensor element formed in a first substrate and at least one optical element formed in a second substrate, the first and second substrates being configured relative to one another such that the second substrate forms a cap over the first sensor element. The cap includes a diffractive optical element and an aperture stop which collectively determine the wavelength of incident radiation that is allowed through the cap and onto the at least one optical element.

Abstract: A spectrophotometer having an optical system for directing a beam of substantially monochromatic excitation light to a liquid sample contained in a well (3) of a well plate for interaction with the sample for absorption or emission measurements to analyse the sample. The optical system includes two apertures (46, 28) for establishing a Kohler illumination region outside the well, that is an excitation beam region between conjugate images (18, 21) of the two apertures. This excitation beam region is then demagnified and imaged (10, 9) into the well (3). The invention provides for the shape of the Kohler illumination region to correspond to the shape of the well space so that all of the liquid sample is uniformly illuminated without the well obstructing any portion of the illuminating excitation beam of light.

Abstract: A hemispherical goniophotometer is disclosed, in which two pivoting arms are articulated on a revolving rotating arm and are each fitted with a measurement head. The geometry of the arrangement is chosen such that the measurement heads can move along the envelope surface of a hemisphere during rotating of the rotating arm through 360° and pivoting of the pivoting arms through 180°.

Abstract: An optical measurement device capable of improving optical spectrum measurement accuracy without the need to structurally decrease a slit width. A diffraction grating for dispersing measurement light into respective different wavelengths is rotated in a given direction to produce diffracted light of selected wavelengths. A focusing lens converges the diffracted light to produce a converged beam. A slit control section varies the slit width at a constant scan speed to open or close the slit, thereby varying the passing bandwidth for the converged beam. A light receiving/measuring section receives the light passed through the slit, obtains a level function indicative of the power level of the received light that varies with change in optical frequency, and differentiates the level function by the scan speed to reproduce the spectrum profile of the measurement light.

Abstract: An atomic absorption spectrometer is disclosed which includes a monochromater (30) and an optical path defined by a toric mirror (14), a flat mirror (16), a flat mirror (20), a flat mirror (24), a toric mirror (22) and a further toric mirror (26). The toric mirror (26) directs light through entrance slit (32) of the monochromater (30) so that radiation is reflected from diffraction grating (38) and out exit slit (40) to a detector (42). A sample stage (18) in the form of a furnace is located between the mirrors (16) and (20). The monochromater is oriented so that the entrance slit is arranged transverse to the vertical.

Abstract: A monochromator for isolating or recombining a narrowband optical signal from a broadband signal. A cylinder with a continuous outer wall and two planar end surfaces is composed of a dispersive medium. The cylinder forms a multi-reflective cavity, wherein a broadband optical signal entering the cavity through an end surface at an angle of incidence to the outer wall is repeatedly totally internally reflected off the outer wall. The outer wall includes exit points for permitting egress of spectral components. For recombination, narrowband optical signals are coupled into the body at different locations on the outer wall and propagated in substantially helical paths that converge at an end surface. The propagation path within the dispersive medium can thus be lengthened in a relatively compact space. The monochromator has low insertion loss, and does not require fine adjustment or particularly careful handling.

Abstract: A spectrometer for correcting a displacement of a dispersed light image having a light source for outputting a monochromatic ray of light, an optical system which images a dispersed light image of the monochromatic ray through an incident slit on an imaging plane, a sensor array, and a calculator for calculating a variation in an imaging position of a primary dispersed light image of the monochromatic ray through the incident slit on the imaging plane from its initial position as a first image displacement amount, and a variation in an imaging position of a secondary dispersed light image of the monochromatic ray through the incident slit from its initial position as a second image displacement amount, and calculating, based on the first and second image displacement amounts, a third image displacement amount which is free of an influence due to a fluctuation of a wavelength of the monochromatic ray.

Abstract: A monochromator system applicable in spectrophotometer, polarimeter and ellipsometer systems which operate over a large range of wavelengths, including a stage which enables position adjustment of the location of a source of electromagnetic radiation in lateral (X), longitudinal (Y) and vertical (Z) directions, from a common location outside an enclosure, and including multiple detector systems mounted in a manner which allows easily, sequentially, via mechanical motion, placing a first and then a second thereof so as to receive a beam of electromagnetic radiation.

Abstract: A monochromator including: a concave mirror which converts incident light into parallel light and emits the parallel light, a plane diffraction grating for diffracting the parallel light emitted from the concave mirror, first reflection means which reflects first light diffracted by the plane diffraction grating and causes the diffracted light to enter the plane diffraction grating as second incident light, second reflection means which reflects second diffracted light and causes the reflected light to enter the plane diffraction grating as third incident light, and an exit slit disposed in the vicinity of a focal point such that third diffracted light is reflected by the first reflection means, to thereby enter the plane diffraction grating as fourth incident light and such that fourth diffracted light is converged at the focal point by the concave mirror, to thereby enable extraction of light having a specific wavelength.

Abstract: An electrically adjustable spectrometer uses collimated, P-polarized light made incident on a surface of an optically transparent liquid crystal input material. The material transmits the light to a boundary surface between the input material and an output optically transparent material. The input material is preferably highly dispersive, making Snell component values at the boundary surface markedly different for different wavelengths. The output material is preferably of low dispersion and high birefringence. Only one wavelength at the boundary surface has a Snell component value tangent to its corresponding index surface in the output section. Within this section, the ray vector for this wavelength is parallel to the boundary surface. Because optical energy propagates in the ray vector direction, only the narrow range of wavelengths having ray vectors substantially parallel to the boundary surface reach an output of the device.

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: 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: There is provided a mirror supporting structure for a monochromator capable of turning the mirrors about axis lines which cross each other, thereby adjusting the attachment angles of the mirrors in two directions. The mirror supporting structure for a monochromator comprises first angle adjusting means for turning the mirrors about each first axis line which does not cross each plane direction of the mirrors and second angle adjusting means for turning the mirrors about each second axis line which does not cross each plane direction of the mirrors at right angles but is parallel with a line crossing the first axis line.

Abstract: A chemical imaging system is provided which uses a near infrared radiation microscope. The system includes an illumination source which illuminates an area of a sample using light in the near infrared radiation wavelength and light in the visible wavelength. A multitude of spatially resolved spectra of transmitted, reflected, emitted or scattered near infrared wavelength radiation light from the illuminated area of the sample is collected and a collimated beam is produced therefrom. A near infrared imaging spectrometer is provided for selecting a near infrared radiation image of the collimated beam. The filtered images are collected by a detector for further processing. The visible wavelength light from the illuminated area of the sample is simultaneously detected providing for the simultaneous visible and near infrared chemical imaging analysis of the sample. Two efficient means for performing three dimensional near infrared chemical imaging microscopy are provided.

Abstract: A high resolution spectral measurement device. 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 microdensitometer system capable of micrometer resolution for reading radiochromic films, includes: a film holder for supporting a radio chromic film sample; a high-precision scanning stage including a monochromatic light source for illuminating the film sample; a CCD microscope camera for a photographing light from the light source that is transmitted through the film sample; and a microcomputer for analysing data relayed from the CCD microscope camera. The film sample is translated by the scanning stage to enable analysis of the whole film sample.

Abstract: Plane diffraction grating 13 is formed of a material having an appropriate linear expansion coefficient and a variation in the wavelength of the reflected light from concave mirror 14 on account of thermal expansion or shrinkage of members other than plane diffraction grating 13 is cancelled out or reduced by a variation in the wavelength of the reflected light from concave mirror 14 on account of thermal expansion or shrinkage of plane diffraction grating 13. The same principle is used to deal with the effect on the wavelength of the diffracted light that may be caused by changes in the layout of individual members on account of thermal expansion or shrinkage of substrate 10a that fix them.

Abstract: A diffraction grating and a prism with the appropriate characteristics are employed to provide a combined dispersive characteristic that is substantially linear over the visible spectrum. Radiation from the grating and prism is collimated by a lens towards a detector array. The grating or a telecentric stop between the grating and prism is placed at a focal point of the lens in a telecentric arrangement so that equal magnification is achieved at the detector array. If the detector array is replaced by a plurality of optical channels, a multiplexer/demultiplexer is obtained.

Abstract: A spectrometer uses collimated, P-polarized light made incident on a surface of an optically transparent material at angle &thgr;INC. The material transmits the light which reaches a boundary surface between the input material and an output optically transparent material. The input material is preferably highly dispersive, making Snell component values at the boundary surface markedly different for different wavelengths. The output material is preferably of low dispersion and high birefringence. Only one wavelength at the boundary surface has a Snell component value tangent to its corresponding index surface in the output section. Within this section, the ray vector for this wavelength is parallel to the boundary surface. Because optical energy propagates in the ray vector direction, only the narrow range of wavelengths having ray vectors substantially parallel to the boundary surface reach an output surface of the device. This narrow range of wavelengths comprises the passband incident on a detector.

Abstract: A simple, reliable, easy to use method for calculating bandwidth data of very narrow band laser beams based on bandwidth data obtained with a spectrometer in circumstances where the laser bandwidths are not large compared to the slit function of the spectrometer. The slit function of the spectrometer is determined. Spectral data of the laser beam is measured with the spectrometer to produce a measured laser beam spectrum which represents a convolution of the laser beam spectrum and the spectrometer slit function. This measured laser spectrum is then mathematically convolved with the slit function of the spectrometer to produce a doubly convolved spectrum. Bandwidth values representing true laser bandwidths are determined from measured laser spectrum and the doubly convolved spectrum. Preferably the true laser bandwidths are calculated by determining the difference between “twice a measured laser bandwidth” and a corresponding “doubly convolved bandwidth”.

Abstract: An embedded data acquisition and control system for a precision instruments, such as a non-invasive glucose prediction instrument is disclosed. One feature of the invention provides synchronization of stepper motor position and analog-to-digital converters. An embedded controller is provided that controls the stepper motor driver directly to minimize the wavelength shift error due to the asynchronous condition. The controller synchronizes the event of reading the A/D converters with each stepper motor position. Because the stepper motor controls the wavelength of the monochromator optical output, the net result is that each A/D conversion recorded by the embedded controller is precisely tracked to a specific wavelength. Another feature of the invention provides closed loop motor position control for enhanced system performance. In the closed loop system, a position encoder is coupled to the stepper motor shaft.

Abstract: A spectrometer has a source of illumination radiation having a plurality of spectral wavelengths, a bandpass filter, a dispersive beamsplitter disposed in an optical path of said source of illumination radiation, an illumination radiation rejection filter, and a spectrograph disposed in a path of radiation from a sample illuminated by illumination radiation from said source of illumination radiation. The dispersive beamsplitter, the bandpass filter, the illumination radiation rejection filter and spectrograph are tunable in correspondence to a selected one of the plurality of spectral wavelengths of the source of illumination radiation. The dispersive beamsplitter directs the selected one of the plurality of spectral wavelengths of illumination radiation to a sample and directs elastically scattered and reflected radiation from the sample out of a measurement beam of light emanating from the sample.

Abstract: In the monochromator, when measured beam which is diffracted by a plane diffraction grating is collected by a collimator to be returned, the measured beam is displaced by a displacement member in a direction parallel to rulings of the plane diffraction grating and is passed through a first cut-off slit having a slit of a predetermined width formed in a direction perpendicular to the direction of the rulings.

Abstract: There is provided a mirror supporting structure for a monochromator capable of turning the mirrors about axis lines which cross each other, thereby adjusting the attachment angles of the mirrors in two directions. The mirror supporting structure for a monochromator comprises first angle adjusting means for turning the mirrors about each first axis line which does not cross each plane direction of the mirrors and second angle adjusting means for turning the mirrors about each second axis line which does not cross each plane direction of the mirrors at right angles but is parallel with a line crossing the first axis line.

Abstract: A high resolution etalon-grating monochromator. 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.