DD223244A1 - OPTICAL SYSTEM FOR SPECTRAL UNITS - Google Patents

Abstract

The invention relates to an optical system for Spektralgeraete, which is used for simultaneous detection of multiple, selectively selected spectral segments from an overall spectrum on a picture and in particular a line receiver. The available receiver area should be used as completely as possible and without any gaps for analytical investigations. For this purpose, several spectral sections are to be selected from a gas mass spectrum and to be imaged directly adjacent to the receiver surface. There are associated with a dispersing member at least approximately adjacent to its meridional focal plane adjacent, along this plane and in a plane substantially perpendicular to the plane displaceable selectors assigned. figure

Description

Title: Optical system for spectral devices Field of application of the invention:

The invention relates to an optical system for spectral devices having a light inlet opening, an imaging, dispersing member and a receiver coupled to a display unit and a supply, control and evaluation.

It comes in the emission and absorption spectrometry for simultaneous detection of multiple, selectively selected, short spectral segments of a generated by the dispersing member total spectrum of a ray. -. source of application. , ^y ,

As receiver image receiver, in particular Zeileriempfanger are provided.

Characteristic of the known technical solutions

The known technical solutions generate selected spectral sections which are not sharply delimited in the receiver plane, which are imaged overlapping or without a defined local arrangement. Thus, a spectrometer system is known in which the dispersion increase by multiple beam guidance via the diffraction grating spectral sections reach an outlet opening adjacent to the light inlet opening.

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Another technical solution provides, η defined inlet openings from a radiation source forth. to be transmitted through η light divider. The dispersive optical system produces η spectral sections of equal length and a defined displacement relative to one another according to the arrangement of the entrance openings. ^J. '-

The disadvantage is, that the superposition of the .. spectral background of all. Spectra sections. While it is known to divert 'the individual sections in addition' vertically, in the direction of the used grid, this solution is unusable for line receivers. .. ^v

Object of the invention . , , ''

By the invention is to be achieved that the available receiver surface as completely as possible and \ gapless fto

is exploited, with only the spectral segments; imaged on the receiver surface, which are required for the analysis. , ·

Explanation of the essence of the invention

The object of the invention is to select a plurality of spectral segments from an overall spectrum and to image them directly adjacent to one another without mutual overlaps occurring. - '- ·.' '. This is achieved according to the invention in that the dispersing member are at least approximately in the meridional Cup level adjacent arranged, along this plane and in a. To the plane substantially vertical direction slidable selectors are assigned., Each of the selectors consists of ζτ / ei Hef lesions el a nt en,

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whose reflective surfaces are inclined towards each other and face the dispersing member. In the angle enclosed by the reflecting surfaces, a diaphragm displaceable along the bisecting line is provided with at least one variable gap opening. ·

By the use of the selectors, it is achieved on the assumption that the selector elements are tuned to one another so that a convergent light beam which diffracts from the dispersing member and initially falls on one of the two reflecting surfaces undergoes a deflection which Aperture radiates and is directed through the other reflective surface again on the dia- 'pergender member.

The aperture is the part of the selector lying in the mirrored meridional focus of the dispersing member.

The angular position of the two reflective surfaces causes the light beam is imaged after passing through a selector and re-diffraction on the grid next to the sipe opening. ,

The aperture in each selector becomes one ^; sharply limited, directed to the receiver spectral section selected.

For the selection of wavelengths of interest are. , -. '.'

1. The selectors along the required extent. the Folsalebene and

2. to move to the illustration next to the inlet opening on the receiver in the direction perpendicular thereto.

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3. The apertures are to be opened, depending on the width of the spectral range to be selected, and displaced along the angular direction so that the beam deflected by the first reflecting surface can pass through the aperture and be imaged onto the desired spot of the receiver.

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, the immediate Uebeneinanderabbildung the selected Spektreiischnschni ¬ te reached. To order as many selectors as possible, '

.müssen, intake opening and receiver as close as possible adjacent and possibly even offset to cup level gegen'sein. \

For the Pail, that the Smpfänger and the light entrance opening are offset from each other to cup level, the Reflesions.elementen in the beam path before or arranged downstream provided with at least one variable gap opening aperture, which is the beam path substantially vertically slidably. Is. In this arrangement, the convergent light beam diffracted by the dispersing member either falls first on the diaphragm and then on the two reflecting elements or first one after the other on the reflecting elements and then on the diaphragm, before returning to the dispersing member By the gate and field order of the aperture su the reflection elements of the displacement of the entrance slit is counteracted so that the diaphragm remains essentially im.Fokus.

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- 5 embodiment

The invention will be explained in more detail below with reference to the schematic drawing. Ss show:

Pig. 1 is a plan view of an optical arrangement according to the invention

Pig. 2 is a plan view of a selector

In Pig. 1 are a light source 1, an imaging optics 2 and arranged downstream as a gap 3 light entrance opening. A concave grating 4 is used to disperse a LichtbundeIs represented by its center beam 5, which generates from the light source 1, the imaging optics 2 and the gap 3 passes through. The concave grating 4 divides the light beam corresponding to the center beam 5 by wavelengths and diffracts it as a focused light beam, which is represented by its - center beam 6, su at least approximately in its meridional Cup level 7 arranged selector 8, along the plane 7 and in a to vertical direction 9 is displaced. The embodiment is for the sake of clarity only one. Selector limited. To fulfill the task, it is necessary to arrange several selectors adjacent to the cup level. _; , '. , The selector δ is, as in Pig. 2, composed of mutually inclined planar mirrors 10, 11, in whose included angle a 'displaceable in the direction of 9 aperture 12 is provided with a modified gap 13. The mirrors 10, 11 have. Mirror surfaces 14, 15, which face the concave grating 4.

The center beam 6 is deflected by the mirror 10; passes through the gap 13 and is directed by the mirror 11 as a beam 16 onto the concave grating 4.

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The concave grating 4 diffracts the focused light beam, shown as beam 16, onto a photosensitive receiver 17 ₍ image or line receiver 18, adjacent to the gap J , arranged in the cup plane 7 of a ₍ image or line receiver 18) which is equipped with a monitor 19 and a power supply. , Control and evaluation is coupled. '..

The directed onto the image receiver 18 light beam is represented by its center beam 21. The displacement of the selector 8 along the cup plane 7 and along the direction 9, as well as the gap width adjustment of the gap 13 and the displacement of the diaphragm 12 in the direction 9 ensure the selection of a specific spectral portion from a total spectrum and its mapping. a selectable area of the receiver surface 17 x. By a larger number of selectors 8 located adjacent in the cup level 7 are more. Spectra sections from the entire spectrum selectively ' ¹ ' bar to the first adjacent to the receiver surface.

The gap 3 and the Smpfängerfläche 17 should therefore be möglich.dicht.benachbart and possibly - arranged offset to the cup level 7 against each other. Due to the displacement of the gap 3 along the center beam 5 , the aperture 12 arranged in the mirror 10 and 11 will no longer lie in the original meridional cup level 7 of the concave grating. Depending on the direction of displacement of the gap 3, therefore, the aperture 12 between the concave grating 4 and your mirror 10 or between the mirror 11 and the concave

, grating 4th, in substantially vertically displaceable to the beams 6 and 16: to order. , , , Of course, the mirrors 10 and 11 can also be replaced by other deflection elements which achieve the same effect. , - - '

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Aasteile level mirror can also use curved mirror surfaces for the simultaneous correction of astigmatic error and slit image curvature. Of course, also the entrance slit can be given a suitable curvature in order to produce on the image receiver as straight as possible, monochromatic slit images.

By radiation which passes through the selectors in the opposite direction to that shown in FIG. 1, a combination of spectral sections which are closely adjacent to one another and can be registered by an additional image receiver is also formed on the side of the entrance slit opposite the image receiver. If radiation of certain wavelengths is to be constantly detected, it is also possible to provide receivers (for example photodiodes or photomultipliers) in the cup plane behind fixed columns. By carrying out the apertures in the selectors as rotating apertures (taking into account the slit image curvature) or by periodically releasing the apertures, different selectors may have the same adjustment parameters, so that superimposed on the image receiver, the -imaged spectral sections. , , '.

Frequency-selective electronic filtering then separates the individual spectral information sequentially. By a suitable choice of the blazed wavelength and the grating line number of the diffraction grating, it can be achieved that only radiation after two diffraction at the grating is registered by the image receiver and radiation is located directly outside the focal plane (unique _, diffraction) outside the spectral sensitivity of the image receiver.

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For closely adjacent, too. registering spectral segments, the aperture of one or more selectors may also have two or more columns; proportional to the distances in the aperture, the spectral sections are then distributed on the image receiver. Unequipped areas on the image receiver can be illuminated by other selectors. , ·,

For absorption measurement, it is possible to use cuvettes with sample solution or with a blank solution between the concave grating and the image receiver.

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Also within, the selector can be the

• Arrange apertures adjacent to plan-parallel objects to be irradiated.

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Claims (3)

- 9 Claim for invention 1. Optical system for spectral equipment with a Licliteintrittsöffnung, an imaging, dispersing member and coupled to a reproducing unit and a supply, control and evaluation receiver, characterized in that the dispersing member at least approximately adjacent to its meridional Cup level adjacent, along this plane and in a plane substantially vertical direction shiftable selectors are assigned. 2. An optical system according to item 1, characterized in that each of the selectors consists of two reflection elements whose reflective surfaces are inclined to each other and facing the dispersing member, and provided in the included angle along the bisecting slidable diaphragm with at least one variable gap opening is. 3. An optical system according to item 1, characterized in that each of the selectors consists of two reflection elements whose reflective surfaces are inclined to each other facing the dispersing member and that one of the reflection elements in. Beam path upstream or downstream, provided with at least one variable gap opening aperture is provided, which is the beam path substantially vertically displaceable. For this 1 page drawings WES / kl .___ 4352 21.11.1983