CN116660192A - Attenuated total reflection test accessory for Fourier transform infrared spectrometer - Google Patents
Attenuated total reflection test accessory for Fourier transform infrared spectrometer Download PDFInfo
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- CN116660192A CN116660192A CN202210155879.1A CN202210155879A CN116660192A CN 116660192 A CN116660192 A CN 116660192A CN 202210155879 A CN202210155879 A CN 202210155879A CN 116660192 A CN116660192 A CN 116660192A
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- atr
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- parabolic reflector
- fourier transform
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- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 title claims abstract description 26
- 238000012360 testing method Methods 0.000 title claims abstract description 19
- 238000005102 attenuated total reflection Methods 0.000 title claims description 9
- 239000013078 crystal Substances 0.000 claims abstract description 32
- 230000003287 optical effect Effects 0.000 claims description 37
- 238000013519 translation Methods 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 3
- 229910003460 diamond Inorganic materials 0.000 claims description 2
- 239000010432 diamond Substances 0.000 claims description 2
- 238000001514 detection method Methods 0.000 abstract description 6
- 230000004907 flux Effects 0.000 abstract description 6
- 230000010287 polarization Effects 0.000 abstract description 5
- 230000035945 sensitivity Effects 0.000 abstract description 4
- 238000000034 method Methods 0.000 description 4
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000002329 infrared spectrum Methods 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000001210 attenuated total reflectance infrared spectroscopy Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- -1 coatings Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
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- 230000001678 irradiating effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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- 238000011160 research Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000000411 transmission spectrum Methods 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
- G01N2021/0106—General arrangement of respective parts
- G01N2021/0112—Apparatus in one mechanical, optical or electronic block
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N2021/3595—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using FTIR
Abstract
The invention discloses an ATR test accessory for a Fourier transform infrared spectrometer, which comprises an iris diaphragm, a polarizer, a convex parabolic reflector, a concave parabolic reflector, a hemispherical ATR crystal, a convex parabolic reflector, a concave parabolic reflector and an analyzer in sequence along the direction of a light path. The invention utilizes the iris diaphragm to control the light spot size, the polarizer to control polarization, and the concave and convex parabolic reflectors to realize the convergence and parallelism of light beams, and improves the utilization rate of the output luminous flux of the spectrometer by symmetrically arranging the concave-convex parabolic reflectors relative to the hemispherical ATR, thereby ensuring the detection sensitivity and the like. The invention has wide application prospect.
Description
Technical Field
The invention relates to an infrared spectrum technology, in particular to an attenuated total reflection test accessory for a Fourier transform infrared spectrometer.
Background
The principle of fourier transform infrared (Fourier Transform Infrared, FTIR) spectrometers is: the infrared broadband light source is incident on a Michelson interferometer formed by a movable mirror and a fixed mirror, light obtained by scanning the movable mirror is incident on a measured sample, an interference pattern is obtained by a detector, and then a spectrogram is obtained by inverse Fourier transform. The sample chamber of a typical FTIR spectrometer is disposed between the interferometer output light and the detector, and the measurement of transmission spectrum, reflection spectrum, etc. can be easily achieved by placing a suitable transmission, reflection, etc. testing device in the sample chamber and fixing the sample appropriately. FTIR spectrometers have the advantages of high resolution, high accuracy, and broad spectrum range, and are widely used for the detection of trace substances in gases, liquids, and solids. At present, the method has great application requirements in the fields of chemical industry, biomedicine, safety inspection, environmental protection and the like.
Attenuated total reflection (Attenuated Total Reflectance, ATR) is used as a high-sensitivity optical signal testing technology, and the accuracy of infrared spectrum detection is remarkably improved. There are various alternatives to the prism shape for constructing ATR crystals, of which Kretschmann hemispherical prisms are used for research. The hemispherical prism can ensure that incident light at any angle is perpendicular to the interface, so that the propagation direction of the light entering the prism is not changed, and the loss of luminous flux is greatly reduced. The method is widely applied to surface component analysis of polymer material products such as fibers, plastics, coatings, rubber and the like.
The ATR and the FTIR spectrometer are combined to play the advantages of the ATR and the FTIR spectrometer, so that the application can be expanded, and meanwhile, the excellent test sensitivity and the signal-to-noise ratio are obtained. Theoretically, ATR spectroscopic test analysis can be achieved by simply placing the ATR apparatus in the FTIR spectrometer sample compartment. But in practical application, the following problems are faced: the inside of the ATR device is reflected by the lenses for multiple times, the main light path of the ATR device is not coplanar with the incident surface of each lens, the polarization test can not be carried out by a method of placing a polarizing plate outside the ATR device, and the coupling mode/efficiency of the optical signal and the ATR crystal is low. This severely restricts the application and popularization and the use effect of ATR spectroscopy.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides an attenuated total reflection test accessory for a Fourier transform infrared spectrometer, which is matched with an optical path of the FTIR spectrometer, has high optical signal coupling efficiency and can be produced in batches by adopting a symmetrical structure.
The ATR accessory for detecting the optical characteristics of the medium utilizes the iris diaphragm to control the size of a light spot, the polarizer to carry out polarization test, the convex parabolic reflector and the concave parabolic reflector to realize the parallelism and convergence of light beams, and the concave parabolic reflector is symmetrically arranged relative to a hemispherical ATR crystal to improve the utilization rate of the output luminous flux of the spectrometer, so that the detection sensitivity and the signal to noise ratio are ensured; the combination of the concave-convex parabolic mirror reflector and the hemispherical ATR crystal is utilized to realize the optimal matching with the output light path of the Fourier transform spectrometer and the light path of the detector, so that the device has the characteristics of compactness and easy integration.
The invention has wide application prospect in the fields of physics, chemistry, materials, biomedicine and the like.
The technical scheme of the invention is as follows:
a compact high throughput ATR apparatus for a fourier transform spectrometer, characterized by: the device comprises a three-dimensional translation adjustment base, an iris diaphragm, a polarizer, an ATR integrated optical path and an analyzer; wherein the ATR integrated optical circuit is arranged on the three-dimensional translation adjustment base; the ATR integrated optical path comprises an incident optical path and an emergent optical path which are symmetrically distributed about the y direction, wherein the incident optical path and the emergent optical path share a convex parabolic mirror, a concave parabolic mirror and a hemispherical ATR crystal, and the iris diaphragm, the polarizer, the convex parabolic mirror, the concave parabolic mirror, the hemispherical ATR crystal, the concave parabolic mirror, the convex parabolic mirror and the analyzer are sequentially arranged along the optical path direction.
By selecting the clear aperture size of the iris diaphragm and the polarization adjustment of the polarizer, the matching of the beam characteristics from the interferometer in the sample bins of different Fourier transform spectrometers can be realized.
The convex parabolic mirror is parallel to the diverging beam from the light source.
The concave parabolic reflector converges the collimated light beam from the convex parabolic reflector and outputs the collimated light beam from the convex parabolic reflector to the light detector of the FTIR spectrometer via the hemispherical ATR crystal and the concave parabolic reflector in sequence. The size of the clear aperture and the effective focal length of the convex parabolic reflector and the concave parabolic reflector are selected to ensure that the device can be matched with the beam diameters and F/# numbers of light paths of detectors of different Fourier transform spectrometers, and meanwhile, the geometric dimension of the device is compactified through symmetrical structural distribution.
The ATR crystal is made of any material such as diamond, znSe or Ge and has a hemispherical shape, the horizontal plane of the ATR crystal is a sample test surface, and the spherical surface of the ATR crystal is symmetrical to the convex parabolic reflector and the concave parabolic reflector respectively; the concave parabolic reflector converges the collimated light from the convex parabolic reflector on one side of the ATR crystal, and the collimated light is totally reflected by the ATR crystal level and then emitted to the concave parabolic reflector from the other side of the ATR crystal, and the light beam is collimated and transmitted to the analyzer by the convex parabolic reflector.
Compared with the prior art, the invention has the beneficial effects that:
the convex parabolic reflector and the concave parabolic reflector are combined, so that serious loss of optical signals caused by incidence and emergence of the hollow light pipe on the optical conduction component is avoided; the use of optical lenses is avoided by the beam collimation/convergence function of the parabolic mirror, thereby eliminating band limitation. The ATR accessory has the characteristics of high light flux, small light energy loss and wide applicable wave band.
The symmetrical integrated structure of the combination of the convex parabolic reflector and the concave parabolic reflector ensures simple integration with the FTIR spectrometer and efficient pickup of optical signals, and obviously reduces the space size requirement of the ATR device, so that the ATR device is suitable for a sample bin of the built-in FTIR spectrometer. The operation process is simplified, the use difficulty is reduced, the application field is obviously enlarged, and the simple mass production is convenient.
The combination of the concave parabolic reflector and the ATR crystal is adopted to realize the convergence of the interference light beam of the FTIR spectrometer to the ATR crystal and the coupling of the emergent light of the ATR crystal and output the collimated light beam, thereby ensuring that the interference light of the FTIR spectrometer passes through the two sides of the ATR efficiently and further maximizing the extraction of the ATR optical signal. The off-axis parabolic reflector clear aperture and the effective focal length can be selected according to the size requirement of the ATR crystal horizontal plane contact sample area, and the luminous flux of the ATR device and the signal-to-noise ratio of the ATR spectrum detection sensitivity are also obviously improved, so that the applicable sample range of the ATR device is obviously enlarged.
The variable diaphragm is adopted to control the light spot size of incident light, so that the light spot size changed into parallel light beams by the convex parabolic reflector is controlled, and meanwhile, the light spot size focused to the hemispherical ATR crystal by the concave parabolic reflector is adopted, so that the light flux is flexibly regulated and controlled.
The polarizer and the analyzer are adopted to regulate incident light and emergent light, so that the influence of polarization on sample detection can be explored.
Drawings
FIG. 1 shows a schematic diagram of an attenuated total reflection test accessory for a Fourier transform infrared spectrometer of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings, which should not be construed as limiting the scope of the invention.
Fig. 1 shows a block diagram of a compact high throughput ATR apparatus for a fourier transform spectrometer of the present invention. The compact high-flux ATR accessory for the Fourier transform spectrometer comprises a three-dimensional translation adjustment base, an iris diaphragm, a polarizer, an ATR integrated optical path and an analyzer; wherein the ATR integrated optical circuit is arranged on the three-dimensional translation adjustment base (7); the ATR integrated optical path comprises an incident optical path and an emergent optical path which are symmetrically distributed in the y direction, wherein the incident optical path and the emergent optical path share a convex parabolic mirror (2), a concave parabolic mirror (3) and a hemispherical ATR crystal (4), and the iris diaphragm (1), the polarizer (2), the convex parabolic mirror (3), the concave parabolic mirror (4), the hemispherical ATR crystal (5), the concave parabolic mirror (4), the convex parabolic mirror (3) and the analyzer (6) are sequentially arranged in the optical path direction.
In the figure, the right horizontal left arrow represents the interferometric modulated non-collimated beam exiting by the interferometer of the FTIR spectrometer onto the convex parabolic mirror (2).
The position orientation of the iris diaphragm (1) and the polarizer (2) ensures that the incident light beam is coaxial with the center of the aperture of the diaphragm.
The position orientation of the convex parabolic mirror (3) ensures that the parallel light beam reflected by it impinges exactly on the concave parabolic mirror (4) with the beam spot distributed centrally thereon.
The concave parabolic reflector (4) is positioned and oriented to ensure that the focused light beam reflected by the concave parabolic reflector irradiates the front side surface of the ATR crystal (5), penetrates the crystal to irradiate the crystal horizontal plane, and emits non-collimated light after totally reflecting and irradiating the other side surface of the ATR crystal (5) through the interface between the plane and a tested sample.
The position orientation of the ATR crystal (5) ensures that it is centered on the axis of symmetry of the concave parabolic mirror (4) and that the horizontal planes of the two coincide.
The position orientation of the analyzer (6) is such that its non-collimated output beam is coaxial with the interferometric modulated beam from the FTIR spectrometer as shown by the left horizontal arrow in the figure and the output beam matches the optical detector path aperture size and F/# of the FTIR spectrometer as shown by the right horizontal arrow in the figure.
The size of the integrated optical path of the ATR accessory, the clear aperture and the effective focal length of the concave-convex parabolic reflector are adjusted, and the integrated optical path can be matched with FTIR spectrometers with different clear apertures and/or F/# numbers so as to realize the test of the sample bin of the built-in spectrometer of the ATR accessory.
The size of the effective reflection/transmission surfaces of the horizontal plane and the two side surfaces of the ATR crystal (5) is changed, and the clear aperture and the F/# number of the convex parabolic reflector (3) and the concave parabolic reflector (4) are matched and adjusted, so that the requirements of different sample contact surface sizes and/or ATR signal intensity can be met.
According to the presently preferred construction of the present invention, both the ATR crystal and the parabolic mirror are fixed in a suitable mechanical support to meet the different requirements for the spatial position of each mirror described above; three-dimensional adjustment mechanisms are provided as needed to ensure accurate placement of the specific orientations of the mirrors.
Finally, it should be noted that the examples are disclosed for the purpose of aiding in the further understanding of the present invention, but those skilled in the art will appreciate that: various alternatives and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the invention should not be limited to the disclosed embodiments, but rather the scope of the invention is defined by the appended claims.
Claims (2)
1. An attenuated total reflection test accessory for a fourier transform infrared spectrometer, characterized by: the device comprises a three-dimensional translation adjustment base, an iris diaphragm, a polarizer, an ATR integrated optical path and an analyzer; wherein the ATR integrated optical circuit is arranged on the three-dimensional translation adjustment base; the ATR integrated optical path comprises an incident optical path and an emergent optical path which are symmetrically distributed in the y direction, wherein the incident optical path and the emergent optical path share a convex parabolic mirror (2), a concave parabolic mirror (3) and a hemispherical ATR crystal (4), and the iris diaphragm (1), the polarizer (2), the convex parabolic mirror (3), the concave parabolic mirror (4), the hemispherical ATR crystal (5), the concave parabolic mirror (4), the convex parabolic mirror (3) and the analyzer (6) are sequentially arranged in the optical path direction.
2. An attenuated total reflection test accessory for a fourier transform infrared spectrometer as defined in claim 1, wherein: the ATR crystal (4) is made of diamond, znSe or Ge material, has a hemispherical shape, the horizontal plane of the ATR crystal is a sample test surface, a test sample is placed on the horizontal plane during test, and the spherical surface is respectively symmetrical with the convex parabolic reflector and the concave parabolic reflector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210155879.1A CN116660192A (en) | 2022-02-21 | 2022-02-21 | Attenuated total reflection test accessory for Fourier transform infrared spectrometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210155879.1A CN116660192A (en) | 2022-02-21 | 2022-02-21 | Attenuated total reflection test accessory for Fourier transform infrared spectrometer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116660192A true CN116660192A (en) | 2023-08-29 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210155879.1A Pending CN116660192A (en) | 2022-02-21 | 2022-02-21 | Attenuated total reflection test accessory for Fourier transform infrared spectrometer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116660192A (en) |
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2022
- 2022-02-21 CN CN202210155879.1A patent/CN116660192A/en active Pending
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