Abstract: One embodiment provides an optical spectrometer. The optical spectrometer can include a lens-and-filter system configured to collect light scattered from a sample, a spot converter configured to convert a substantially circular beam outputted from the lens-and-filter system into a substantially rectangular beam, and a slit comprising a rectangular aperture to allow a predetermined portion of the substantially rectangular beam to enter the rectangular aperture while blocking noise. The slit can further include at least one microelectromechanical systems (MEMS)-based movable structure configured to adjust a width of the rectangular aperture.

Abstract: An illumination device for a spectral optical measurement device includes arranged with respect to an optical axis of the illumination device which, during a measurement operation, extends along a normal to a center point of an area of a sample to be illuminated. One or more segments of a mirror in a shape of a ring are centered on the optical axis. The mirror has an internal reflective surface arranged such that, during the measurement operation, the internal reflective surface receives light emitted from the light source and reflects the light over the area of the sample to be illuminated. The internal reflective surface has a freeform shape in a cross-section through the internal reflective surface in a plane parallel to the optical axis (for example in which the optical axis lies), and, in a cross-section of the mirror in a plane perpendicular to the optical axis, the internal reflective surface is represented by a straight line.

Abstract: An optical system to divide a light flux from an object plane includes a first curved-surface mirror, and second, third, and fourth reflecting portions. The second reflecting portion divides and reflects light flux from the first curved-surface mirror to respective different positions on the first curved-surface mirror as first light fluxes. The third reflecting portion reflects, as third light fluxes, the first light fluxes. The fourth reflecting portion reflects the third light fluxes from the third reflecting portion. A number of reflective surfaces of each of the third and fourth reflecting portions on which the first and third light fluxes are incident is the same as a division number in the dividing of the light flux into the second light fluxes. The first and third light fluxes are reflected by the respective third and fourth reflecting portions to be image-formed so that divided images of the object plane are formed.

Abstract: The present invention provides a concave diffraction grating capable of improved diffraction efficiency by suppressing spherical aberration. The concave diffraction grating is a concave diffraction grating 2 for dispersing and focusing light and comprises sawtooth grating grooves 21 on a concave substrate 24, with the sawtooth grating grooves 21 being unequally spaced. The concave diffraction grating 2 for dispersing and focusing light is formed by preparing a planar diffraction grating with a sawtooth shape which is formed on a planar substrate by photo-lithography and etching or machining and which forms unequally spaced grating grooves 21, deforming and mounting the planar diffraction grating along a fixed convex substrate to obtain a mold of a concave diffraction grating, and transferring the mold of the concave diffraction grating to the surface of a metal or a resin.

Abstract: A stray light reducing apparatus includes a light source and an entrance slit positioned to pass through light from the light source. A first monochromator mirror is positioned to reflect light passed through the entrance slit. A diffractive surface is positioned to receive and diffract light reflected by the first monochromator mirror. A second monochromator mirror is positioned to reflect light diffracted by the diffractive surface. An exit slit is positioned to pass through light reflected by the second monochromator mirror. A cuvette is positioned to pass through light passed through the exit slit. A long-pass interference filter is positioned to receive light from the light source, reflect light that has a wavelength below a selected value, and pass through light having a wavelength above the selected value. A first sample detector is positioned to receive light reflected by the long-pass interference filter.

Abstract: An energy-resolving x-ray detection system is provided, the system including at least one x-ray optic configured to receive x-rays having an energy bandwidth with a maximum x-ray energy. The at least one x-ray optic has at least one concave surface extending at least partially around and along a longitudinal axis. The at least one concave surface is curved in at least one cross-sectional plane parallel to the longitudinal axis and is configured to direct at least some of the received x-rays into at least one convergent x-ray beam having a minimum beam width in a plane perpendicular to the longitudinal axis. The minimum beam width is at a location and the at least one concave surface has an x-ray reflectivity less than 30% for x-rays having energies greater than one-third of the maximum x-ray energy. The system further includes at least one energy-dispersive x-ray detector configured to receive at least a portion of the at least one convergent x-ray beam.

Abstract: A metrology system includes an illumination source to generate an illumination beam, a multi-channel spectral filter, a focusing element to direct illumination from the single optical column to a sample, and at least one detector to capture the illumination collected from the sample. The multi-channel spectral filter includes two or more filtering channels having two or more channel beam paths. The two or more filtering channels filter illumination propagating along the two or more channel beam paths based on two or more spectral transmissivity distributions. The multi-channel spectral filter further includes a channel selector to direct at least a portion of the illumination beam into at least one selected filtering channel to filter the illumination beam. The multi-channel spectral filter further includes at least one beam combiner to combine illumination from the two or more filtering channels to a single optical column.

Abstract: Embodiments of the present disclosure provide for a colloidal amorphous silicon liquid filter device, methods of using a colloidal amorphous silicon liquid filter device, and the like.

Abstract: A tunable laser source that includes multiple gain elements and uses a spatial light modulator in an external cavity to produce spectrally tunable output is claimed. Several designs of the external cavity are described, targeting different performance characteristics and different manufacturing costs for the device. Compared to existing devices, the tunable laser source produces high output power, wide tuning range, fast tuning rate, and high spectral resolution.

Abstract: Aspects of a tandem dispersive range monochromator and data knitting for the monochromator are described herein. In one embodiment, the monochromator includes a tandem diffraction grating, a grating drive motor that rotates the tandem diffraction grating to provide, by diffraction of broadband light, first dispersed wavelengths of light and second dispersed wavelengths of light, a detector that detects a first reflection from the first dispersed wavelengths of light and a second reflection from the second dispersed wavelengths of light, and processing circuitry that knits together data values from the first reflection and data values from the second reflection to provide a spectrum of combined data values. By using a tandem diffraction grating having different dispersive surfaces, measurements of relatively high precision and quality may be taken throughout a wider spectral range, and the measurements may be knitted together to provide a spectrum of combined data values.

Abstract: A transportable goniospectrometer with a constant observation center for a radiometric measurement of the reflection of a natural surface includes a spectrometer having an optical unit and a sensor. A main pillar has a lower and an upper pillar end. An arc has a fixed and a free arc end. A slide is disposed displaceably and fixably along the arc. The slide carries the optical unit orientated towards the observation center. A cantilever has a fixed cantilever end connected to the upper pillar end via a screw connection, and a free cantilever end which has a suspension that is rotatable and fixable about a vertical axis. The suspension is connected to the sensor and to the fixed arc end of the arc. The suspension is configured to position the arc at a distance of the arc radius of the arc above the natural surface.

Abstract: Provided is a method for performing a wavelength calibration of a monochromator with a diffraction grating by casting light from a standard light source whose emission intensity contains a change with a predetermined cycle onto the diffraction grating and measuring an intensity of light reflected by the grating. The method includes the steps of: measuring at least two times the intensity of the reflected light from the grating within the aforementioned cycle at each of the rotational positions of the grating corresponding to a range of wavelengths including a peak wavelength of a bright line spectral light generated by the standard light source; determining an intensity value 201 at each rotational position based on all the measured values obtained at the rotational position; and locating, as the peak wavelength of the bright line spectral light, a wavelength at which the intensity value 201 is maximized.

Abstract: Aspects of a tandem dispersive range monochromator are described herein. In one embodiment, the monochromator includes a light source that provides broadband light, a tandem diffraction grating including a first diffraction grating and a second diffraction grating, a grating drive motor that rotates the tandem diffraction grating to provide dispersed wavelengths of light, a detector that detects a portion of the dispersed wavelengths of light, and processing circuitry that controls a grating drive motor to regulate an angular velocity of the tandem grating based on an angular orientation of the tandem diffraction grating. By using a tandem diffraction grating having different dispersive surfaces, measurements of relatively high precision and quality may be taken throughout a wider spectral range. In another aspect, the processing circuitry controls a sample drive motor to vary an angle of incidence of the dispersed wavelengths of light onto a sample for evaluation.

Abstract: A spectrometer includes: an entrance aperture, a collimator, intended to produce, from a light source, a collimated input light (5), a plurality of gratings arranged in a 2-D matrix, a plurality of detectors, and an exit aperture.

Abstract: A method and apparatus for assay of multiple analytes. The method uses a sensing element comprising a substrate upon which is arranged a multiplicity of recognition elements, such that each element is laid out in a predetermined pattern. Each pattern is unique in that it can give rise to a characteristic diffraction pattern in the assay. The patterns may or may not be interpenetrating on the substrate surface. The method of detecting multiple analytes includes contacting the medium of analytes with the patterned substrate, illuminating the substrate by a light source, and detecting any resultant diffraction image. The pattern of diffraction and the intensity of the diffracted signal provides information about the existence of specific analytes and their quantification.

Abstract: The present invention provides apparatuses including a point light source, a diffraction grating oriented in a light path generated from the point light source wherein the diffraction grating diffracts and concentrates light from the point light source into one or more rings of light, a detector positioned to detect one or more of the rings of light or light transmitted from a sample exposed to said rings of light, and a computer operably connected to the detector to analyze the intensity of one or more of the rings of light or said light transmitted from said sample. Variations including samples and additional components and methods of making the apparatuses of the present invention are also disclosed.

Abstract: An apparatus for optical spectrometry utilizes a simplified construction, reducing the number of independent optical elements needed while providing a sizeable dispersed spectrum. The apparatus provides a spectral intensity distribution of an input source wherein individual spectral components in the source can be measured and, in some embodiments, can be manipulated or filtered.

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 present invention provides methods and apparatuses for in situ chemical analysis of liquid sample for the collection, identification, and measurement of chemical moieties, such as, biotoxins, organic compounds, or chemical contaminants, in aquatic environments. The apparatuses of the present invention relate to an automated in situ sampler for chemical stressors that adversely impact biological systems in aquatic environments. The apparatuses of the present invention are designed as a means to automatically collect liquid (e.g., water) samples and analyze them for the presence of chemical moieties. The apparatuses of the present invention are designed to automatically collect multiple liquid samples, extract and separate chemical moieties contained within the samples, and analyze the chemical moieties to determine the composition and concentration of the chemical moieties over time and space.

Abstract: An apparatus for optical spectrometry utilizes a simplified construction, reducing the number of independent optical elements needed while providing a sizeable dispersed spectrum. The apparatus provides a spectral intensity distribution of an input source wherein individual spectral components in the source can be measured and, in some embodiments, can be manipulated or filtered.

Abstract: The present application discloses a system comprising a compact curved grating (CCG) and its associated compact curved grating spectrometer (CCGS) or compact curved grating wavelength multiplexer/demultiplexer (WMDM) module and a method for making the same. The system is capable of achieving a very small (resolution vs. size) RS factor. In the invention, the location of the entrance slit and detector can be adjusted in order to have the best performance for a particular design goal. The initial groove spacing is calculated using a prescribed formula dependent on operation wavelength. The location of the grooves is calculated based on two conditions. The first one being that the path-difference between adjacent grooves should be an integral multiple of the wavelength in the medium to achieve aberration-free grating focusing at the detector or output slit (or output waveguide) even with large beam diffraction angle from the entrance slit or input slit (or input waveguide).

Abstract: An apparatus for optical spectrometry utilizes a simplified construction, reducing the number of independent optical elements needed while providing a sizeable dispersed spectrum. The apparatus provides a spectral intensity distribution of an input source wherein individual spectral components in the source can be measured and, in some embodiments, can be manipulated or filtered.

Abstract: Various embodiments provide an optical system including an optical spectrometer, a first negative power mirror configured and arranged to receive radiation from a far-field object, a second positive power mirror configured and arranged to receive radiation reflected by the first negative power mirror, and a third positive power mirror configured and arranged to receive radiation reflected by the second positive mirror and to direct the radiation towards an entrance slit of the optical spectrometer.

Abstract: A system and method of determining an attribute of a biological tissue sample or a drug delivery device. A sample is illuminated with substantially monochromatic light to thereby generate Raman scattered photons. The Raman scattered photons are assessed to thereby generate a spectroscopic data set wherein said spectroscopic data set comprises at least one of: a Raman spectra and a spatially accurate wavelength resolved image. The spectroscopic data set is evaluated to determine at least one of: an attribute of a biological tissue sample and a drug delivery device. In one embodiment, the biological tissue comprises arterial tissue. In another embodiment, the drug delivery device is a drug-eluting stent. In another embodiment, Raman chemical imaging can be used to evaluate a sample and identify at least one of: the tissue, a drug, a drug delivery device, and a matrix associated with a drug delivery device.

Abstract: This disclosure relates generally to a sampling device, and more particularly, a sampling device that facilitates spectroscopic measurements with a variable path length and the necessary software controlled algorithms and methods for such a device.

Abstract: An air quality instrumentation system for a concentrated solar power generation system using a fluid heat transfer medium includes a pipe, a window and a spectroscope. The pipe extends from the concentrated solar power generation system and contains system air from within the concentrated solar power generation system. The window is positioned within the pipe to permit light to pass through the pipe and the system air. The spectroscope is positioned adjacent the window to assess concentration of a constituent within the system air, the concentration of the constituent providing an indication of an operating condition of the concentrated solar power generation system.

Abstract: An optical spectrum analyzer includes a diffraction-grating control unit configured to change an angle of a diffraction grating to change a wavelength of a dispersed light beam extracted from incident light, a calculator unit configured to calculate an angle of the diffraction grating such that the wavelength of the dispersed light beam has a sampling wavelength, and to store the data indicating the angle, a FIFO memory configured such that part of the data is inputted to it, for outputting the data at each reception of a trigger signal indicating timing of sampling, and an FIFO memory control unit configured to output the subsequent data to the FIFO memory, when a remaining data amount of the FIFO memory reaches a predetermined value or lower.

Abstract: An optical assembly for double passing a transmission grating may include a prism having first, second and third surfaces. A transmission grating may be bonded to the first surface. A first mirror coating may be bonded to the second surface and a second mirror coating to the third surface. The first, second and third surfaces, the transmission grating and the first and second mirror coatings are configured such that light of a predetermined wavelength entering the prism that is incident on the transmission grating is diffracted a first time by the transmission grating towards the second surface, reflected from the second surface to the third surface, reflected from the third surface back to the transmission grating, and diffracted a second time by the transmission grating as the light exits the prism.

Abstract: Provided is a spectrum detector capable of being miniaturized and which does not require complicated optical axis alignment. The spectrum detector of the present invention comprises: a substrate; a photodetector formed on the substrate and including a semiconductor having a plurality of convex portions; and a wavelength detection circuit for detecting a wavelength of light transmitted through the plurality of convex portions, from light incident on the photodetector. According to the present invention, a small-sized spectrum detector can be provided which can easily detect a peak wavelength distribution included in light of an unknown wavelength, without the use of optical equipment such as a grating or prism, thus dispensing with the need for the optical axis alignment of a complex optical system.

Abstract: A novel means of correcting the motion of an analytical instrument is introduced herein based on the determination of the optimal theoretical parameters in the equation of grating angle versus a selected wavelength. Such a desirable correction method of the present invention not only reduces the amount of wavelength error at the calibration points but also in a novel fashion beneficially corrects for errors in a time-efficient manner between the calibration points to a greater degree than conventional calibration methods.

Abstract: The invention is directed to a highly sensitive spectrum analysis unit with a diffraction grating, wherein a parallel light bundle having a wavelength range impinges on a diffraction grating which splits the different wavelengths into spectra by diffraction in first directions, and wavelength partial ranges of the spectrally split light bundle can be focused on a detector row by means of camera optics, and evaluation electronics are connected to the detector row and acquire the generated spectrum as information and display it. The invention is characterized in that the light bundle passes a first optical element, and then wavelength partial ranges of a spectrally split light bundle impinge on respective partial regions of a diffraction grating, the diffraction grating having the same grating constant across all partial regions and a changing profile shape, the profile shapes generating different blaze wavelengths that lie in the respective wavelength partial ranges.

Abstract: An improved optic system for measuring and/or controlling displacement, force, pressure, position, or chemistry is disclosed. This apparatus allows for more accurate, robust, and economical communication between the transducer (or control input element) and the reader device (or control output), allows the use of a single optic fiber and/or or a gap for the communication link, and produces substantial insensitivity to attenuation due to mechanical, chemical, thermal, and radiation effects acting on the optic fiber or open space in which the signal propagates. It is also significantly immune to interference from electromagnetic radiation, since the link can be easily produced as a non-conductor which will not propagate unwanted electrical energy or lightning, and is intrinsically safe from igniting fires or explosions. It also facilitates use on rotating machinery and remote location of the transducer by the ability to transmit the signal across a large gap or air space.

Abstract: The present invention provides a highly reliable spectral module. The spectral module (1) of the present invention comprises a substrate (2) for transmitting therethrough light incident on one surface (2a); a lens unit (3), having an entrance surface (3a) opposing the other surface (2b) of the substrate (2), for transmitting therethrough the light entering from the entrance surface (3a) after passing through the substrate (2); a spectroscopic unit (4), formed with the lens unit (3), for spectrally resolving and reflecting the light having entered the lens unit (3); a photodetector (4) for detecting the light reflected by the spectroscopic unit (4); and a support unit (8), disposed between the other surface (2b) and the entrance surface (3a), for supporting the lens unit (3) against the substrate (2).

Abstract: In a spectral module 1, a photodetector 5 is mounted to an intermediate substrate 81, whereby an optical resin agent 63 interposed between a front face 2a of a substrate 2 and the intermediate substrate 81 is prevented from intruding into a light transmitting hole 50 of the photodetector 5. This can prevent refraction, scattering, and the like from occurring and make light Li appropriately enter a spectroscopic unit 4. In addition, the intermediate substrate 81 has a volume smaller than that of the substrate 2, whereby the intermediate substrate 81 expands/shrinks in a state more similar to the photodetector 5 than the substrate 2 when the temperature in the surroundings of the spectral module 1 changes. Hence, bump connections of the photodetector 5 can more reliably be prevented from breaking upon changes in the temperature in the surroundings of the spectral module 1 than when the photodetector 5 is mounted to the substrate 2.

Abstract: The present invention provides a highly reliable spectral module. When light L1 proceeding to a spectroscopic unit (4) passes through a light transmitting hole (50) in the spectral module (1) in accordance with the present invention, only the light having passed through a light entrance side unit (51) formed such as to become narrower toward a substrate (2) and entered a light exit side unit (52) formed such as to oppose a bottom face (51b) of the light entrance side unit (51) is emitted from a light exit opening (52a). Therefore, stray light M incident on a side face (51c) or bottom face (51b) of the light entrance side unit (51) is reflected to the side opposite to the light exit side unit (52) and thus is inhibited from entering the light exit side unit (52). Therefore, the reliability of the spectral module (1) can be improved.

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: 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: An apparatus for optical spectrometry utilizes a simplified construction, reducing the number of independent optical elements needed while providing a sizeable dispersed spectrum. The apparatus provides a spectral intensity distribution of an input source wherein individual spectral components in the source can be measured and, in some embodiments, can be manipulated or filtered.

Abstract: A spectroscope of the present invention includes a concave diffraction grating which disperses incident light, an incident light introduction unit which introduces incident light into the concave diffraction grating, and an outgoing light receiving unit which receives outgoing light dispersed for different wavelengths by the concave diffraction grating. The spectroscope further includes an incident aperture which limits an incident angle of light emitted by the incident light introduction unit to the concave diffraction grating, and an outgoing aperture which limits an outgoing angle of outgoing light dispersed for different wavelengths by the concave diffraction grating to the light receiving unit. The spectroscope is constructed so that relatively rotational transfer of at least two out of the concave diffraction grating, the incident aperture and the outgoing apertures can be performed along a Rowland circle which the concave diffraction grating forms.

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.

Abstract: The method of the present invention generates a regularly lined electric field inside a container 1 retaining a sample formed by dispersing particle groups in a liquid by a voltage being applied to an electrode pair 2 provided in the container 1, generates a diffraction grating by a density distribution of the particle groups in the sample inside the container 1, and when acquiring a diffusion coefficient of particles from a temporal variation of intensity in a disappearing process of a diffracted light obtained by irradiating a beam of light to the diffraction grating generated by the density distribution of the particle groups, performs a particle size analysis of the particle groups by using an approximate analysis expression of a diffracted light attenuation, I(t)=?exp[?2q2Dt] which uses q=2?/? defined by a particle concentration modulation period ? in the density distribution diffraction grating of the particle groups, and the Einstein-Stokes relation.

Abstract: The present application discloses a system comprising a compact curved grating (CCG) and its associated compact curved grating spectrometer (CCGS) or compact curved grating wavelength multiplexer/demultiplexer (WMDM) module and a method for making the same. The system is capable of achieving a very small (resolution vs. size) RS factor. In the invention, the location of the entrance slit and detector can be adjusted in order to have the best performance for a particular design goal. The initial groove spacing is calculated using a prescribed formula dependent on operation wavelength. The location of the grooves is calculated based on two conditions. The first one being that the path-difference between adjacent grooves should be an integral multiple of the wavelength in the medium to achieve aberration-free grating focusing at the detector or output slit (or output waveguide) even with large beam diffraction angle from the entrance slit or input slit (or input waveguide).

Abstract: For the high spatial resolution imaging of a structure in a sample (2) the structure is marked with a substance which can be changed over by means of a first electromagnetic signal (5) from a first state having a larger absorption cross section for a second electromagnetic signal (3) into a second state having a smaller absorption cross section for the second signal (3) or which can be changed over by means of a first electromagnetic signal (5) into a first state having a larger absorption cross section for a second electromagnetic signal (3) from a second state having a smaller absorption cross section for the second signal (3). A spatially delimited distribution of a portion of the substance in the first state is then set by means of the first signal (5). Afterward, the second electromagnetic signal (3) is applied to the sample (2), and a local temperature increase in the sample (2) which results from the larger absorption cross section of the substance in the first state is detected.

Abstract: An optical wavemeter includes a slit, a diffraction grating, a mask, a complementary grating, and a detector. A monochromatic source is incident on the slit. The diffraction grating produces an image of the slit in an image plane at a horizontal position that is wavelength dependent. The mask has a two-dimensional pattern of transmission variations and produces different vertical intensity channels for different spectral channels. The complementary grating produces a stationary image of the slit independent of wavelength. The detector measures vertical variations in intensity of the stationary image, and the mask is created so that the number of measurements made by the detector is less than the number of spectral channels sampled.

Abstract: The invention relates to a device for the positioning of optical elements with retractable stop enabling accurate positioning of an optical element selected among a plurality of optical elements, including a stand (1); a turret fitted with a element holder and a disc (4), said disc (4) being a ratchet wheel having a peripheral surface (5) fitted with a plurality of blocking means (6), each blocking means (6) corresponding to an optical element, a motor (7) and a crash stop (9) bearing against the peripheral surface of the disc (5). According to the invention the stop (9) contains an anti-friction element (13) in contact with the peripheral surface (5) of the ratchet wheel so that the retractable stop (9) moves according to the contour of the peripheral surface (5) of the ratchet wheel without any friction.

Abstract: A calibrated spectroscopy instrument and a method for calibrating a spectroscopy instrument are disclosed. The spectroscopy instrument includes a monochromator having a drive mechanism comprising a pair of spur gears for rotating a diffraction grating of the monochromator for selecting a desired wavelength. The drive mechanism is calibrated to account for eccentricities in the spur gears to provide an accurate conversion between selected angular settings for the drive mechanism and the wavelength of the diffracted light from the monochromator. The drive mechanism comprises a pinion spur gear and a main spur gear which each have an AGMA (American Gear Manufacturers' Association) rating of at least 10, which allows errors due to random tooth to tooth variations to be neglected. A calibration algorithm is derived which is based on the error due to eccentricities in the spur gears following a precise geometric cyclic pattern.

Abstract: A novel scanning monochromator uses a PM stepper-motor to directly drive a diffraction grating. By employing interpolated encoder feedback in combination with the PM stepper-motor feedback, a resolution of over 250,000 pulsed steps is available for each revolution of the PM stepper-motor. This translates into more than 20,000 incremental angular-displacement steps over a usable 30° range of dispersion-element rotation. High field accuracy is achieved by a direct PM stepper-driven diffraction grating, and a unique calibration approach based on Wood's anomalies. A plurality of diffracted light beams emerge from the oscillating grating, and these are scanned past a detector for detection, whereby the relative rotation information of the grating can be detected with great accuracy. A number of tolerance-correcting measures are also included to yield an extremely accurate, self-lubricating scanning monochromator that can be economically produced.

Abstract: The present invention is directed to a monochromator device which uses single grating volume holograms. The holograms collect light of varying wavelengths such as polychromatic light, and separate one particular wavelength of interest. A wide wavelength spectrum can be targeted, either by angularly tuning the holograms, or by using an array of holograms each of which is tuned to a different center wavelength. The large aperture and high angular dispersion of the volume holograms provides a higher light throughput than that of prior art monochromators. The present invention can be used anywhere that efficient separation of polychromatic light into its narrowband components is required. The monochromator may be placed immediately before a light source, or before other optical or signal processing devices to provide the filtered wavelength of light input to such devices.

Abstract: An optical signal is compressively sampled. An optical component with a plurality of transmissive elements and a plurality of opaque elements is created. The location of the plurality of transmissive elements and the plurality of opaque elements is determined by a transmission function. A spectrum of the optical signal is dispersed across the optical component. Signals transmitted by the plurality of transmissive elements are detected in a single time step at each sensor of a plurality of sensors dispersed spatially with respect to the optical component. Each sensor of the plurality of sensors produces a measurement resulting in a number of measurements for the single time step. A number of estimated optical signal values is calculated from the number of measurements and the transmission function. The transmission function is selected so that the number of measurements is less than the number of estimated optical signal values.

Abstract: An optical signal is copressively sampled using an imaging system. The imaging system is created from a plurality of subimaging systems. Each subimaging system comprises a subaperture and a plurality of sensors. The optical signal is collected at each subaperture of the plurality of subimaging systems at a single time step. The optical signal is transformed into a subimage at each subimaging system of plurality of subimaging systems. The subimage includes at least one measurement from a plurality of sensors of each subimaging systems. An image of the optical signal is calculated from the sampling function and each subimage, spatial location, pixel sampling function, and point spread function of each subimaging system of the plurality of subimaging systems. The sampling function is selected so that the number of measurements from a plurality of subimages is less than a number of estimated optical signal values in the image.