Leibniz-institut Fur Analytische Wissenschaften - Isas - E.v.

Gesellschaft Zur Förderung Der Analytischen Wissenschaften E.v.

Zentralinstitut Fur Optik Und Spektroskopie

Other

Bodenseewerk Perkin-elmer Gmbh

Leibniz-institut Fur Analytische

Gesellschaft Zur Förderung Angewandter Optik, Optoelektronik, Quantenelektronik Und Spektroskopie E.v.

Gesellschaft Zur Förderung Angewandter Optik, Optoelektronik, Quantenelektronik Und Spektroskonie E. V.

Leibniz - Institut Für Analytische Wissenschaften

Helmut Becker-Ross

Stefan Florek

Michael Okruss

Reiner Guther

Uwe Heitmann

A spectrometer assembly (), comprising an Echelle grating () for dispersing radiation entering the spectrometer assembly () in a main dispersion direction, and a dispersion assembly () for dispersing a parallel radiation bundle generated from the radiation entering the spectrometer assembly in a lateral dispersion direction, is characterized in that the dispersion assembly () is reflective, and the dispersion assembly () is arranged relative to the Echelle grating () in such a way that the parallel radiation bundle is reflected in the direction of the Echelle grating. The Echelle grating () may be arranged in such a way that the dispersed radiation is reflected back to the dispersion assembly ().

Spectrometer arrangement

The invention relates to a spectrometer arrangement () having a spectrometer for producing a spectrum of radiation from a radiation source on a detector (), comprising an optical imaging Littrow arrangement () for imaging the radiation entering the spectrometer arrangement () in an image plane, a first dispersion arrangement () for the spectral decomposition of a first wavelength range of the radiation entering the spectrometer arrangement, a second dispersion arrangement () for the spectral decomposition of a second wavelength range of the radiation entering the spectrometer arrangement, and a common detector () arranged in the image plane of the imagine optics, characterized in that the imaging optical arrangement () comprises an element () that can be moved between two positions (), wherein the radiation entering the spectrometer arrangement in the first position is guided via the first dispersion arrangement and in the second position via the second dispersion arrangement.

Spectrometer assembly

A method to determine and correct broadband background in complex spectra in a simple and automatized manner includes carrying out a background correction with respect to broadband background before a calibration step. The background correction may involve recording a spectral graph and smoothing the recorded spectral graph, determining all values in the initially recorded graph having a value higher than the value of the smoothed graph and reducing such values to the value of the smoothed graph, and repeating these two steps. The background graph obtained is then subtracted from the initial graph. The smoothing of the graph is carried out by moving average, where each intensity value I at the position x in the spectrum is replaced by an average value. The characteristics of the found peaks can be stored in a file so that the calibration can be used at any time.

Method for determining background and correction of broadband background

A method for the wavelength calibration of echelle spectra, in which the wavelengths are distributed across number of orders is characterised by the steps: recording of a line-rich reference spectrum with known wavelengths for a number of the lines, determination of the position of a number of peaks of the reference spectrum in the recorded spectrum, selection of at least two first lines of known order, position and wavelength, determination of a wavelength scale for the order in which the known lines lie, by means of a fit function &#x3b3;(x), determination of a provisional wavelength scale &#x3b3;?m 1(x) for at least one neighboring order m 1, by means of addition/subtraction of a wavelength difference &#x3b3;which corresponds to a free spectral region, according to &#x3b3;m 1 ?(x)=&#x3b3;(x)&#x3b3;with &#x3b3;(x)/m, determination of the wavelengths of lines in said neighboring order m 1, by means of the provisional wavelength scale &#x3b3; 1(), replacement of the provisional wavelength of at least two lines by the reference wavelength for said lines as obtained in step (a) and repeat of steps (d) to (g) for at least one further neighboring order.

Method for the analysis of echelle spectra

A spectrometer assembly () is disclosed. The assembly includes a light source () with a continuous spectrum. A pre-monochromator () generates a spectrum with a relatively small linear dispersion from which a spectral portion is selectable, the spectral bandwidth of the spectral portion being smaller than or equal to the bandwidth of the free spectral range of the order in the echelle spectrum. The centre wavelength of the selected spectral interval is measurable with maximum blaze efficiency. The assembly also includes an echelle spectrometer () with means for wavelength calibration, an entrance slit () at the pre-monochromator (), an intermediate slit assembly () with an intermediate slit () and a spatially resolving light detector () in the exit plane of the spectrometer for the detection of wavelength spectra.

Assembly and method for wavelength calibration in an echelle spectrometer

The invention relates to a spectrometer ( ) with a dispersive element ( ) that can be displaced between at least two positions. In the first position, the simply dispersed radiation ( ) of a selected wavelength is reflected directly back in the incident beam path ( ), while in the second position the dispersed radiation ( ) of the selected wavelength can be directed to a reflective element ( ) that is positioned such that the radiation ( ) can be directed at least one more time across the dispersive element ( ) and then back to the incident beam path ( ). The spectrometer is provided with a device, for example, a mirror, an echelle grating or a prism that deflects the beam from the plane of dispersion, which is arranged in such a manner that the simply dispersed beam ( ) runs in another plane than the multiply dispersed beam ( ). The mirror ( ) is inclined by an axis ( ) that extends parallel to the plane of dispersion and perpendicular to the incident beam ( ).

High-resolution littrow spectrometer and method for the quasi-simultaneous determination of a wavelength and a line profile

Echelle polychromator

The invention relates to an Echelle polychromator and can be employed in instruments for the spectrophotometric investigation of radiation sources. It is characterized in that, connected in series with the polychromator, there is a dispersive and polychromatic illuminating device, which is formed from an entrance slit arrangement, collimator optics, prism and camera optics, the entrance slit arrangements of the polychromator and of the illuminating device consisting of a main slit for limiting the bundle in the grating dispersion direction and a transverse slit for limiting the bundle in the direction of the dispersion of the prism in the Echelle polychromator. The whole of the wavelength range, which is to be processed by the polychromator, is imaged completely with negligible aberration on the transverse slit of the Echelle polychromator as a spectrum of the illuminating device. The dispersion of the illuminating device runs in the direction of the transverse dispersion of the prism of the Echelle polychromator. The dispersion-induced geometric width of the spectrum of the illuminating device for the whole of the wavelength region that is to be processed by the polychromator is less than the width of the transverse slit of the Echelle polychromator. Parts of the bundle of rays of the spectrum of the illuminating device are blocked out by the transverse slit of the Echelle polychromator.

The invention relates to a spectrometer useful in analytical spectroscopy. The spectrometer has an imaging diffraction grating, a planar receiver system, and an element for flattening the image field, wherein the improvement comprises that a body of low refractive power and perceptible secondary spectrum is used as the element for flattening the image field, said body having at least two optically active surfaces, and is disposed between the entry slit and the diffraction grating.

Growing community of inventors

Berlin, Germany

Helmut Becker-Ross