Abstract:
The invention concerns an optical component (1), which comprises preferably two prisms (2, 3) and an intermediate transmission grating (4). The radiation is directed by means of the prisms (2, 3) and the radiation is dispersed or collated by means of a grating (4) with big dispersion to direct the wished radiation wavelengths into wished directions.
Abstract:
Un premier monochromateur (14) doté d'une prisme (20) est monté à l'avant d'un polychromateur à échelle (50). La dispersion linéaire du premier monochromateur (14) est susceptible de varier lorsqu'on modifie la dispersion angulaire du prisme (20). Une position spectrale déterminée et son environnement immédiat sont analysés avec une résolution élevée, au moyen d'une grille échelle (54). Des moyens sont prévus afin que, en fonction de chacune des longueurs d'onde moyennes observées, d'une part le réseau détecteur (66) du polychromateur à échelle (50) soit totalement utilisé et, d'autre part, les perturbations soient écartées du polychromateur à échelle (50). Dans ce but, la dispersion linéaire du premier monochromateur est variable.
Abstract:
A device for use with a smart phone or tablet, the device comprising: a measurement device including a light source comprising a plurality of light emitting diodes for measuring one or more physiological parameters, the measurement device configured to generate an input optical beam with one or more optical wavelengths, wherein at least a portion of the one or more optical wavelengths is a near-infrared wavelength 700 nanometres to 2500 nanometres; the measurement device comprising one or more lenses configured to receive and to deliver a portion of the input optical beam to a sample, wherein the sample reflects at least a portion of the input optical beam delivered to the sample; the measurement device further comprising a receiver to receive at least a portion of the input optical beam reflected from the sample; the light source configured to increase a signal-to-noise ratio of the input optical beam reflected from the sample, wherein the increased signal-to-noise ratio results from an increase to the light intensity from at least one of the plurality of light emitting diodes and from modulation of at least one of the plurality of light emitting diodes; the measurement device configured to generate an output signal; and wherein the modulation of at least one of the plurality of light emitting diodes has a modulation frequency, and wherein the receiver is configured to detect at the same frequency as the modulation of the at least one of the plurality of light emitting diodes.
Abstract:
Wavenumber linear spectrometers are provided including an input configured to receive electromagnetic radiation from an external source; collimating optics configured to collimate the received electromagnetic radiation; a dispersive assembly including first and second diffractive gratings, wherein the first diffraction grating is configured in a first dispersive stage to receive the collimated electromagnetic radiation and wherein the dispersive assembly includes at least two dispersive stages configured to disperse the collimated input; and an imaging lens assembly configured to image the electromagnetic radiation dispersed by the at least two dispersive stages onto a linear detection array such that the variation in frequency spacing along the linear detection array is no greater than about 10%.
Abstract:
The bandwidth selection mechanism includes a first actuator mounted on a second face of a dispersive optical element, the second face being opposite from a reflective face, the first actuator having a first end coupled to a first end block and a second end coupled to a second end block, the first actuator being operative to apply equal and opposite forces to the first end block and the second end block to bend the body of the dispersive optical element along the longitudinal axis of the body and in a first direction normal to the reflective face of the dispersive optical element. The bandwidth selection mechanism also includes a second actuator being operative to apply equal and opposite forces to bend the body along the longitudinal axis of the body, in a second direction perpendicular to the reflective face of the dispersive optical element.
Abstract:
The invention relates to a spectrometer assembly (10) containing: a radiation source (11) with a continuous spectrum; a pre-monochromator (2) for generating a spectrum with relatively little linear dispersion, from which a spectral segment can be selected, whose spectral bandwidth is less than or equal to the bandwidth of the free spectral range of the order in the echelle spectrum, for which the mean wavelength of the selected spectral segment can be measured with a maximum blaze efficiency; an echelle spectrometer (4) comprising means for wavelength calibration; an entry slit (21) on the pre-monochromator (2) and an intermediate slit assembly (3) comprising an intermediate slit and a local resolution radiation receiver (5) on the exit plane of the spectrometer for detecting wavelength spectra. The assembly is characterised in that the width of the intermediate slit (3) is greater than the monochromatic image of the entry slit generated by the pre-monochromator at the location of the intermediate slit and that means are provided for calibrating the pre-monochromator, by means of which the radiation that is reproduced in the detector of the radiation source with a continuous spectrum can be calibrated to a reference position.
Abstract:
A spectrometer with a Schmidt reflector is described. The spectrometer may include a Schmidt corrector and a dispersive element as separate components. Alternatively, the Schmidt corrector and dispersive element may be combined into a single optical component. The spectrometer may further include a field-flattener lens.
Abstract:
Spectrum sensors can be continuously calibrated in a manufacturing environment employing a continuously moving platform that carries the spectrum sensors in combination with spatially separated light spectra illuminating a region of the platform. A plurality of spectrum sensors, each including multiple sensor pixels, can be placed on the platform. The spatially separated light spectra can be illuminated over an area of the platform. The plurality of spectrum sensors can be moved with the platform through a region of the spatially separated light spectrum. Each sensor pixel for each of the plurality of spectrum sensors can be calibrated based on response of each spectral channel during passage through the spatially separated light spectra. The entire spectra from a light source can be employed simultaneously to calibrate multiple spectrum sensors in the manufacturing environment.
Abstract:
A measurement system includes a light source having semiconductor sources, a multiplexer, and one or more fused silica fibers configured to form an output optical beam having one or more optical wavelengths modulated at a modulation frequency. A light beam set-up includes a monochromator forming a filtered optical beam. A measurement apparatus delivers the filtered optical beam to a sample. A receiver receives a spectroscopy output beam generated from the sample by the filtered optical beam. The receiver is configured to use a lock-in technique that detects the modulation frequency, and to generate first and second signals responsive to light received while the light source is off and on, respectively. The measurement system improves a signal-to-noise ratio of the spectroscopy output beam by differencing the first and second signals. The receiver processes the spectroscopy output beam using chemometrics or multivariate analysis to permit identification of materials within the sample.