Abstract:
A spectrometer includes: a collimating element configured for collimating a beam of light into a first one of a cross-dispersing element and an echelle grating, the grating in optical communication with the cross-dispersing element; a focusing element for receiving the light from a second one of the cross-dispersing element and the echelle grating and focusing wavelengths of the light onto a spatial light modulator; the spatial light modulator configured for selectively directing the wavelengths onto a detector for detection. A method of use and the method of fabrication are provided.
Abstract:
The present disclosure concerns a spectrometer (10) and method for generating a two dimensional spectrum (S). The spectrometer (10) comprises a main grating (3) and cross dispersion element (2). An imaging mirror (4) is arranged for reflecting and focussing dispersed radiation (R3) from the main grating (3) towards an image plane (IP) for imaging the two dimensional spectrum (S) onto an image plane (IP) of the spectrometer (10). A correction lens (6) is arranged for correcting optical aberrations in the imaging of the two dimensional spectrum (S) in the image plane (IP). The imaging mirror (4) and correction lens (6) have a coinciding axis of cylindrical symmetry (AS).
Abstract:
L'invention concerne un spectromètre imageur de type échelle comprenant une fente longue adaptée pour laisser passer un faisceau optique, un ensemble collimateur adapté pour collimater le faisceau optique, un réseau croisé dit réseau auxiliaire et un réseau échelle dit principal configurés pour réaliser un spectre du faisceau optique doublement multiplexé, un ensemble objectif configuré pour former le spectre sur un ensemble de détection dudit spectromètre.
Abstract:
The invention relates to a spectrometer arrangement (10) comprising an echelle grating (18; 46) for dispersing the radiation entering the spectrometer arrangement (10) in a main dispersion direction, and a dispersion arrangement (16; 40) for dispersing a parallel beam generated from the radiation entering the spectrometer arrangement in a transverse dispersion direction, characterized in that the dispersion arrangement (16; 40) is reflective and disposed with respect to the echelle grating (18; 46) such that the parallel beam is reflected toward the echelle grating. The echelle grating (18; 46) can preferably be disposed such that the dispersed radiation is reflected back toward the dispersion arrangement (16; 40).
Abstract:
A method and apparatus for the spectrochemical analysis of a sample in which a solid state array detector (82) is used to detect radiation (62) of spectrochemical interest. The invention involves the use of a shutter (72) adjacent the entrance aperture (70) of a polychromator (74-80) to expose the detector (82) to the radiation (62) for varying lengths of time whereby for short duration exposure times charge accumulation in elements (i.e. pixels) of the detector (82) due to high intensity components of the radiation is limited and for longer exposure times charge accumulation in elements (pixels) of the detector (82) due to feeble intesity components of radiation (62) is increased. This ensures that each reading of the detector (82) includes at least one exposure in which the amount of charge accumulated at each wavelength of interest is neither too little or too great. The problems of feeble radiation components not being accurately measurable and of high intensity radiation components exceeding the charge carrying capacity of elements (pixels) of the detector (82) are thereby able to be avoided. An attenuator (90) may be placed between the radiation source (60) and the detector (82) to permit longer exposure times to be used for very high intensity radiation.
Abstract:
Ein Gittermonochromator, speziell für Synchrotronstrahlung, mit Sägezahngitter (1) wird mit einer Bedingung für den Zusammenhang von Wellenlänge (Lambda) und Eintrittswinkel (α) betrieben, die nach der elektromagnetischen Beugungstheorie die zweite Beugungsordnung (m = 2) oder eine höhere Beugungsordnung vollständig eliminiert. Dabei ist die Kurve "Lambda (α)" etwa doppelt so hoch, wie im On-Blaze-Betrieb, hat aber bei großen Winkeln (α) ein resonanzartiges Maximum. Der Wirkungsgrad der Beugung erster Ordnung wird erhöht.
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.