Abstract:
The invention relates to a spectrometer arrangement (10) having a spectrometer for producing a spectrum of radiation from a radiation source on a detector (34), comprising an optical imaging Littrow arrangement (18, 20) for imaging the radiation entering the spectrometer arrangement (16) in an image plane, a first dispersion arrangement (28, 30) for the spectral decomposition of a first wavelength range of the radiation entering the spectrometer arrangement, a second dispersion arrangement (58, 60) for the spectral decomposition of a second wavelength range of the radiation entering the spectrometer arrangement, and a common detector (34) arranged in the image plane of the imagine optics, characterized in that the imaging optical arrangement (18, 20) comprises an element (20) that can be moved between two positions (20, 50), 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.
Abstract:
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.
Abstract:
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.
Abstract:
The invention relates to a spectrometer (10) with a dispersive element (16) that can be displaced between at least two positions. In the first position, the simply dispersed radiation (44) of a selected wavelength is reflected directly back in the incident beam path (42), while in the second position the dispersed radiation (32) of the selected wavelength can be directed to a reflective element (30) that is positioned such that the radiation (34) can be directed at least one more time across the dispersive element (16) and then back to the incident beam path (38). 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 (34) runs in another plane than the multiply dispersed beam (36). The mirror (30) is inclined by an axis (54) that extends parallel to the plane of dispersion and perpendicular to the incident beam (32).
Abstract:
An Echelle spectrometer arrangement (10) with internal order separation contains an Echelle grating (34) and a dispersing element (38) for order separation so that a two-dimensional spectrum having a plurality of separate orders (56) can be generated, an imagine optical system (18, 22, 28, 46), a flat-panel detector (16), and predispersion means (20) for predispersing the radiation into the direction of traverse dispersion of the dispersion element (38). The arrangement is characterized in that the predispersion means (20) comprise a predispersion element which is arranged along the optical path behind the inlet spacing (12) inside the spectrometer arrangement. The imaging optical system is designed in such a manner that the predispersed radiation can be imaged onto an additional image plane (24) which does not have any boundaries in the predispersion direction and which is arranged along the optical path between the predispersion element (20) and the echelle grating (34). Optical means (20, 68) in the area of the predispersed spectrum are arranged to influence the spatial and/or the spectral beam density distribution on the detector (16).
Abstract:
The invention relates to a spectrometer arrangement (10) having a spectrometer for producing a spectrum of radiation from a radiation source on a detector (34), comprising an optical imaging Littrow arrangement (18, 20) for imaging the radiation entering the spectrometer arrangement (16) in an image plane, a first dispersion arrangement (28, 30) for the spectral decomposition of a first wavelength range of the radiation entering the spectrometer arrangement, a second dispersion arrangement (58, 60) for the spectral decomposition of a second wavelength range of the radiation entering the spectrometer arrangement, and a common detector (34) arranged in the image plane of the imagine optics, characterized in that the imaging optical arrangement (18, 20) comprises an element (20) that can be moved between two positions (20, 50), 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.
Abstract:
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 γm(x), determination of a provisional wavelength scale γ?m 1(x) for at least one neighboring order m 1, by means of addition/subtraction of a wavelength difference γFSR which corresponds to a free spectral region, according to γm 1 ?(x)=γm(x)γFSR with γFSR=γm(x)/m, determination of the wavelengths of lines in said neighboring order m 1, by means of the provisional wavelength scale γ 1(x), 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.
Abstract:
A spectrometer assembly (10), comprising an Echelle grating (18; 46) for dispersing radiation entering the spectrometer assembly (10) in a main dispersion direction, and a dispersion assembly (16; 40) 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 (16; 40) is reflective, and the dispersion assembly (16; 40) is arranged relative to the Echelle grating (18; 46) in such a way that the parallel radiation bundle is reflected in the direction of the Echelle grating. The Echelle grating (18; 46) may be arranged in such a way that the dispersed radiation is reflected back to the dispersion assembly (16; 40).
Abstract:
A spectrometer assembly (10), comprising an Echelle grating (18; 46) for dispersing radiation entering the spectrometer assembly (10) in a main dispersion direction, and a dispersion assembly (16; 40) 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 (16; 40) is reflective, and the dispersion assembly (16; 40) is arranged relative to the Echelle grating (18; 46) in such a way that the parallel radiation bundle is reflected in the direction of the Echelle grating. The Echelle grating (18; 46) may be arranged in such a way that the dispersed radiation is reflected back to the dispersion assembly (16; 40).
Abstract:
The invention relates to a spectrometer arrangement (10) comprising a spectrometer (14) for producing a spectrum of a first wavelength range of radiation from a radiation source on a detector (42). Said arrangement also comprises: an Echelle grating (36) for the spectral decomposition of the radiation penetrating the spectrometer arrangement (10) in a main dispersion direction (46); a dispersing element (34) for separating the degrees by means of spectral decomposition of the radiation in a transversal dispersion direction (48) which forms an angle with the main dispersion direction of the Echelle grating (36), in such a way that a two-dimensional spectrum (50) can be produced with a plurality of separated degrees (52); an imaging optical element (24, 38) for imaging the radiation penetrating through an inlet gap (20) into the spectrometer arrangement (10), in an image plane (40); and a surface detector (42) comprising a two dimensional arrangement of a plurality of detector elements in the image plane (40). The inventive arrangement is characterised in that another spectrometer (12) comprising at least one other dispersing element (64) and another imaging optical element (60,66) is provided in order to produce a spectrum (68) of a second wavelength range of radiation, which is different from the first wavelength range, from a radiation source on the same detector (42). The spectra can be spatially or temporally separated on the detector.