A double-channel optical path light splitting system based on colorimetric temperature measurement principle

Abstract

The application provides a double-channel light path spectrometer system based on a colorimetric temperature measurement principle, and relates to the field of infrared radiation temperature measurement of aero-engine turbine disc. The double-channel light path spectrometer system comprises a double-band collimating lens group, a dichroic mirror group, a two-way single-band focusing lens group and a light beam collector. The double-band collimating lens group, the dichroic mirror group and the focusing lens group are combined to complete collimation, beam splitting and focusing of incident light. The center wavelengths of two light paths after beam splitting are 2.1 microns and 2.3 microns respectively. Each detection band is selected with a suitable infrared detector to increase the measurable optical channel. Each band lens is fixed in a lens barrel mounting mode to reduce external environmental interference, keep the lens surface clean and the optical performance, and improve the stability and accuracy of the light path. The light beam collector for stray light absorption is added to reduce unnecessary reflected light interference on the system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of infrared radiation temperature measurement of turbine disks of an aero-engine, and discloses a double-channel light path spectrometer system based on the colorimetric temperature measurement principle. BACKGROUND

[0002] As a commonly used non-contact infrared radiation temperature measurement method, the colorimetric temperature measurement has the advantage of not directly contacting the measured object and not affecting the physical properties of the measured sample, and is therefore often applied to temperature measurement under complex conditions such as high temperature, high speed movement or rotation, strong corrosion, etc. However, the colorimetric temperature measurement light path system involves the design of optical structures such as collimation, spectrometry and focusing of the light path, and the number of optical components is large and dispersed, making it difficult to control the relative positions and angles between the lenses and other optical elements, thereby reducing the spectrometry accuracy. In the traditional separated double-channel spectrometry design, the connection and fixing modes between the components are not stable enough, and displacement or deformation is likely to occur during use, resulting in poor spectrometry effect, and the lenses are vulnerable to invasion of external dust, water vapor and the like, which adversely affects the optical performance. In addition, the overall design is not compact enough, and there are obvious limitations in some application scenarios with strict space limitations. SUMMARY

[0003] The present application is designed to improve the deficiencies in the background art and provides a double-channel light path spectrometer system based on the colorimetric temperature measurement principle.

[0004] The present application is designed to improve the deficiencies in the background art and provides a double-channel light path spectrometer system based on the colorimetric temperature measurement principle.

[0005] The dichroic mirror set comprises a dichroic lens mounting lens barrel and a dichroic lens; the inner wall of the dichroic lens mounting lens barrel is coated with a black light-absorbing coating for absorbing reflected and refracted light in the lens barrel; a fixed clamping groove is arranged at the front and back of the dichroic lens mounting lens barrel for mounting the dichroic lens; the dichroic lenses mounted in the front and back fixed clamping grooves of the dichroic lens mounting lens barrel are two different dichroic lenses; the first piece of dichroic lens transmits infrared light of 1.4 μm to 2.4 μm; the second piece of dichroic lens transmits infrared light of 2.0 μm to 2.4 μm and reflects infrared light of 1.9 μm to 2.2 μm; a window is formed in the sidewall of the dichroic lens mounting lens barrel for transmitting the infrared light reflected by the second piece of dichroic lens; the transmittance and reflectance of the two pieces of dichroic lenses in the corresponding wave band are both greater than 95%.

[0006] The second piece of dichroic lens divides the light into two paths, the reflected light path is light path one and the projected light path is light path two, each path corresponds to a single wave band focusing lens set, the single wave band focusing lens set comprises a focusing lens mounting lens barrel, a filter and a focusing lens set.

[0007] Further, the light beam collector is a cylindrical structure with a barrel-shaped opening and a thread surface on the inner wall.

[0008] Further, the lenses in the double wave band collimating lens set are double cemented lenses made of zinc sulfide (ZnS) and zinc selenide (ZnSe) materials, which correct chromatic aberration and thermal aberration in the temperature measurement wave band and reduce the influence on the optical system.

[0009] Further, the inner wall of the focusing lens mounting lens barrel is coated with a black light-absorbing coating, and a fixed clamping groove is left in the focusing lens mounting lens barrel for mounting the filter and the focusing lens set.

[0010] Further, the working wavelength of the band-pass filter in the channel light path one is 2.0 μm to 2.2 μm, and the center wavelength is 2.1 μm; the infrared light after passing through the band-pass filter is output through the focusing lens set.

[0011] Further, the working wavelength of the band-pass filter in the channel light path two is 2.2 μm to 2.4 μm, and the center wavelength is 2.3 μm; the infrared light after passing through the band-pass filter is output through the focusing lens set.

[0012] Further, the light beam collector is a barrel-shaped structure, the inner wall of which is a thread surface, and a conical reflecting device is arranged opposite to the barrel opening at the bottom; when the incident light is transmitted into the light beam collector through the barrel opening, it is first reflected on the surface of the conical reflecting device, then transmitted onto the thread surface, and reflected again onto the surface of the conical device after reaching the thread surface; after multiple reflections, the energy of the incident stray light is gradually attenuated, thereby achieving absorption of the stray light.

[0013] Further, each mounting lens barrel can be independently disassembled, facilitating replacement and upgrading in different optical systems, protecting each lens from physical damage to a certain extent, providing each lens with accurate mounting position and fixed angle during installation, and facilitating fine adjustment of the position and angle of each lens to achieve optimal light splitting effect and improve the stability and reliability of the entire optical system.

[0014] Further, each single-waveband focusing lens group corresponds to an infrared detector, which is a short infrared wave InGaAs detector with a refrigeration function. Through the refrigeration function, the photoelectric detector can maintain a low working temperature, reduce the heat radiation energy emitted by itself, and improve the stability of the photoelectric detector.

[0015] Compared with the prior art, the advantages of the present application are: compared with the traditional separated double-channel optical path design, each lens is mounted in a sealed optical lens barrel to protect each lens from external dust, water vapor and other interference, in addition, the inner wall of each optical lens barrel is coated with a black light-absorbing coating to absorb the reflected and refracted light inside the lens barrel, a light beam collector is added to absorb stray light in the entire optical system, each mounting lens barrel can be independently disassembled, facilitating replacement and upgrading in subsequent optical systems, providing a more compact and reasonable space for the layout of the optical path, and being more miniaturized and integrated, which is conducive to realizing more complex and efficient double-channel light splitting function. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a schematic diagram of a double-channel optical path light splitting system based on the colorimetric temperature measurement principle of the present application;

[0017] Figure 2 is a mounting position diagram of each component in a double-channel optical path light splitting system based on the colorimetric temperature measurement principle of the present application;

[0018] Figure 3 is a light propagation schematic diagram in a double-channel optical path light splitting system based on the colorimetric temperature measurement principle of the present application;

[0019] Figure 4 is an appearance diagram (left) and a sectional view (right) of a double-waveband collimating lens group mounting lens barrel in a double-channel optical path light splitting system based on the colorimetric temperature measurement principle of the present application;

[0020] Figure 5 is an appearance diagram of a dichroic mirror group mounting lens barrel in a double-channel optical path light splitting system based on the colorimetric temperature measurement principle of the present application;

[0021] Figure 6is an appearance view (left) and a sectional view (right) of a waveband 1 focusing lens group mounting lens barrel of a double-channel optical path light splitting system based on the colorimetric temperature measurement principle of the present application;

[0022] Figure 7 is an appearance view (left) and a sectional view (right) of a waveband 2 focusing lens group mounting lens barrel of a double-channel optical path light splitting system based on the colorimetric temperature measurement principle of the present application;

[0023] Figure 8 is an appearance view (left) and a sectional view (right) of a light beam collector of a double-channel optical path light splitting system based on the colorimetric temperature measurement principle of the present application;

[0024] In the figure, 1 is an external optical fiber; 2 is a double-waveband collimating lens group; 3 is a dichroic mirror group; 4 is a single-waveband focusing lens group 1; 5 is an infrared detector 1; 6 is a single-waveband focusing lens group 2; 7 is an infrared detector 2; 8 is a light beam collector; 9 is a double-waveband collimating lens group mounting lens barrel; 10 is a dichroic mirror group mounting lens barrel; 11 is a single-waveband focusing lens group mounting lens barrel 1; 12 is a single-waveband focusing lens group mounting lens barrel 2; 13 is a collimating lens; 14 is a dichroic mirror 1; 15 is a dichroic mirror 2; 16 is a band-pass filter 1; 17 is a single-waveband focusing lens 1; 18 is a band-pass filter 2; 19 is a single-waveband focusing lens 2. DETAILED DESCRIPTION

[0025] The present application provides a double-channel optical path light splitting system based on the colorimetric temperature measurement principle, each lens is mounted by a sealed optical lens barrel, the inner wall of the lens barrel is coated with a black light-absorbing coating, the reflected and refracted light in the lens barrel can be absorbed, a light beam collector is added to absorb stray light in the whole optical system, and the stability and reliability of the whole optical system are improved.

[0026] The collimation, splitting and focusing of the incident light are completed by using the non-modulated optical splitting technology, and the structure of the combination of the double-band collimating lens group, the dichroic mirror group and the single-band focusing lens group. The radiation signal of the measured object is connected with the interface reserved at the rear end of the mounting barrel of the fiber and the double-band collimating lens group, and enters the double-channel optical path splitting system. The light rays are collimated after passing through the double-band collimating lens group, and the divergent light rays become parallel light rays. The chromatic aberration and thermal aberration in the temperature measurement wave band range are corrected by using the double-cemented lens made of zinc sulfide (ZnS) and zinc selenide (ZnSe) in the collimating lens group. The collimated light passes through the dichroic mirror group and is split into two paths. One of the two dichroic mirror pieces can transmit the infrared light with the wavelength of 1.4 μm to 2.4 μm, and the other dichroic mirror piece can transmit the infrared light with the wavelength of 2.0 μm to 2.4 μm and reflect the infrared light with the wavelength of 1.9 μm to 2.2 μm. The transmittance and reflectance of the two dichroic mirror pieces are greater than 95%. The working wavelength of the band-pass filter in the channel optical path one is 2.0 μm to 2.2 μm, and the center wavelength is 2.1 μm. The infrared light after passing through the band-pass filter in the channel is focused by the focusing lens group in the channel and transmitted to the infrared detector. The working wavelength of the band-pass filter in the channel optical path two is 2.2 μm to 2.4 μm, and the center wavelength is 2.3 μm. The infrared light after passing through the band-pass filter in the channel is focused by the focusing lens group in the channel and transmitted to the infrared detector. The lenses are mounted by using the sealed optical barrel, and the inner wall of each optical barrel is coated with black light-absorbing coating to absorb the reflected and refracted light rays in the barrel, and a light beam collector is used to realize the absorption of stray light in the whole optical system.

[0027] The application is further described below with reference to the accompanying drawings:

[0028] Figure 1 Fig. 1 is a schematic diagram of a double-channel optical path splitting system based on the colorimetric temperature measurement principle, Figure 2 Fig. 2 is an installation position diagram of each component in the double-channel optical path splitting system based on the colorimetric temperature measurement principle, Figure 3 Fig. 3 is a light ray propagation schematic diagram of the double-channel optical path splitting system based on the colorimetric temperature measurement principle. The double-channel optical path splitting system includes a double-band collimating lens group 2, a dichroic mirror group 3, a single-band focusing lens group 4, a single-band focusing lens group 7, a light beam collector 8, the double-band collimating lens group 2 includes a collimating lens mounting barrel 9 and a collimating lens 13, the dichroic mirror group 3 includes a dichroic mirror piece mounting barrel 10, a dichroic mirror piece 14 and a dichroic mirror piece 15, the single-band focusing lens group 4 includes a focusing lens mounting barrel 11, a band-pass filter 14 and a focusing lens group 17, the single-band focusing lens group 6 includes a focusing lens mounting barrel 11, a band-pass filter 14 and a focusing lens group 17, the infrared detector device includes a mid-infrared detector 5 and a mid-infrared detector 6, and the light beam collector 8.

[0029] Figure 3 is a schematic diagram of light propagation in a double-channel optical path spectrometer system based on colorimetric temperature measurement principle. The optical fiber is connected to the interface reserved at the rear end of the mounting lens barrel 9. The radiation signal of the measured object enters the double-channel optical path spectrometer system. The radiation signal is collimated after passing through the double-band collimating lens group 9. The divergent light becomes parallel light. The double-cemented lens made of zinc sulfide (ZnS) and zinc selenide (ZnSe) in the collimating lens 13 corrects the chromatic aberration and thermal aberration in the temperature measurement wavelength range. The collimated light is divided into two paths by the dichroic mirror group 3. The dichroic mirror 14 can transmit infrared light of 1.4 μm-2.4 μm. The dichroic mirror 15 can transmit infrared light of 2.0 μm-2.4 μm and reflect infrared light of 1.9 μm-2.2 μm. The transmittance and reflectance of the dichroic mirror 14 and the dichroic mirror 15 are both greater than 95%. The working wavelength of the band-pass filter 16 in the channel optical path one is 2.0 μm-2.2 μm, and the center wavelength is 2.1 μm. The infrared light after passing through the band-pass filter 16 in the channel is focused and transmitted to the infrared detector 5 by the single-band focusing lens 17 in the channel. The working wavelength of the band-pass filter 18 in the channel optical path two is 2.2 μm-2.4 μm, and the center wavelength is 2.3 μm. The infrared light after passing through the band-pass filter 18 in the channel is focused and transmitted to the infrared detector 7 by the single-band focusing lens 19 in the channel.

[0030] Figure 4 is an appearance view (left) and a sectional view (right) of a double-band collimating lens group mounting lens barrel in a double-channel optical path spectrometer system based on colorimetric temperature measurement principle. As shown in the right view, the double-band collimating lens group mounting lens barrel 9 has an optical fiber interface reserved at the rear end. The inner wall of the lens barrel is coated with a black light-absorbing coating to absorb the reflected and refracted light inside the lens barrel. The lens barrel has fixing slots inside for mounting the double collimating lens 13.

[0031] Figure 5 is an appearance view of a dichroic mirror group mounting lens barrel in a double-channel optical path spectrometer system based on colorimetric temperature measurement principle. The inner wall of the lens barrel is coated with a black light-absorbing coating to absorb the reflected and refracted light inside the lens barrel. The lens barrel has fixing slots at the front and rear ends for mounting the dichroic mirror 14 and the dichroic mirror 15.

[0032] Figure 6 is an appearance view (left) and a sectional view (right) of a single-band focusing lens group 1 mounting lens barrel in a double-channel optical path spectrometer system based on colorimetric temperature measurement principle. The inner wall of the lens barrel is coated with a black light-absorbing coating to absorb the reflected and refracted light inside the lens barrel. The lens barrel has fixing slots at the front and rear ends for mounting the band-pass filter 16 and the single-band focusing lens 17.

[0033] Figure 7It is a single waveband focusing lens group 2 mounting lens barrel appearance (left) and its sectional view (right) in a double-channel optical path light splitting system based on colorimetric temperature measurement principle, the inner wall of the lens barrel is coated with black light-absorbing coating, which is used to absorb the reflected and refracted light in the lens barrel, and fixing slots are left at the front and rear ends of the lens barrel for mounting the band-pass filter 18 and the single waveband focusing lens 19.

[0034] Figure 8 It is a light beam collector appearance (left) and its sectional view (right) in a double-channel optical path light splitting system based on colorimetric temperature measurement principle, the light beam collector has a barrel-shaped structure, the inner wall is a threaded curved surface, a conical reflecting device is mounted at the bottom, and a light transmission hole is arranged on the outer incident surface opposite the conical device. When the incident light is transmitted to the inside of the light beam collector through the light transmission hole, it will first be reflected on the surface of the conical device, transmitted to the threaded curved surface, and then reflected to the surface of the conical device after reaching the threaded curved surface. After multiple reflections, the energy of the stray light will gradually attenuate, thereby realizing the absorption of stray light.

[0035] According to the above embodiment, the present application uses non-modulated optical splitting technology, adopts the structure of double waveband collimating lens group, dichroic mirror group and focusing lens combination to complete the collimation, beam splitting and focusing of incident light, and completes the design of double-channel optical path light splitting based on colorimetric temperature measurement principle. The sealed optical lens barrel is used to install each lens, which protects each lens from external dust, water vapor and other interference, and to a certain extent, protects each lens from physical damage from the outside. During installation, the lens barrel provides accurate installation position and fixed angle for each lens, which can more conveniently fine-tune the position and angle of each lens to achieve the best light splitting effect. In addition, the inner wall of each optical lens barrel is coated with black light-absorbing coating to absorb the reflected and refracted light in the lens barrel, increase the light beam collector, and realize the absorption of stray light in the entire optical system. Each mounting lens barrel can be independently disassembled, which is convenient for replacement and upgrading in subsequent optical systems, provides more compact and reasonable space for the layout of the optical path, and has higher miniaturization and integration. Each mounting lens barrel can be independently disassembled, which is convenient for replacement and upgrading in different optical systems, improves the stability and reliability of the entire optical system. Any modification, equivalent replacement, modification, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A double-channel optical path light splitting system based on the colorimetric temperature measurement principle, characterized in that: The double-channel light path splitting system comprises an outer box, a double-waveband collimating lens group, a dichroic mirror group, two single-waveband focusing lens groups and a light beam collector. The double-waveband collimating lens group comprises a collimating lens group mounting lens barrel and a collimating lens group. The collimating lens group mounting lens barrel has a front end reserved optical fiber interface, a black light-absorbing coating is coated on the inner wall of the collimating lens group mounting lens barrel, and a fixing groove is reserved in the inner part of the collimating lens group mounting lens barrel for mounting the collimating lens group.

2. The dual-channel optical path splitting system based on the colorimetric temperature measurement principle according to claim 1, characterized in that, The double-waveband collimating lens is composed of double cemented lenses and collimates the incident infrared light.

3. The dual-channel optical path splitting system based on the colorimetric temperature measurement principle according to claim 1, characterized in that, The dichroic mirror group comprises a dichroic mirror mounting lens barrel and a dichroic mirror.

4. The dual-channel optical path splitting system based on the colorimetric temperature measurement principle according to claim 1, characterized in that, The dichroic mirror mounting lens barrel has a black light-absorbing coating coated on the inner wall, and a fixing groove is reserved in front of and behind the dichroic mirror mounting lens barrel for mounting the dichroic mirror.

5. The dual-channel optical path splitting system based on the colorimetric temperature measurement principle according to claim 1, characterized in that, The first dichroic mirror transmits infrared light with a wavelength of 1.4 μm to 2.4 μm, and the second dichroic mirror transmits infrared light with a wavelength of 2.0 μm to 2.4 μm and reflects infrared light with a wavelength of 1.9 μm to 2.2 μm.

6. The dual-channel optical path splitting system based on the colorimetric temperature measurement principle according to claim 1, characterized in that, The second dichroic mirror splits the light into two paths, and the reflected light path is light path one and the transmitted light path is light path two.

7. The dual-channel optical path splitting system based on the colorimetric temperature measurement principle according to claim 1, characterized in that, Each path corresponds to a single-waveband focusing lens group, and the single-waveband focusing lens group comprises a focusing lens mounting lens barrel, a filter and a focusing lens group. The light beam collector has a cylindrical structure with a barrel-shaped opening and a threaded curved surface on the inner wall. The lenses in the double-waveband collimating lens group are double cemented lenses made of zinc sulfide (ZnS) and zinc selenide (ZnSe) materials, which correct chromatic aberration and thermal aberration in the temperature measurement waveband range and reduce their impact on the optical system. The focusing lens mounting lens barrel has a black light-absorbing coating coated on the inner wall, and a fixing groove is reserved in the inner part of the focusing lens mounting lens barrel for mounting the filter and the focusing lens group. The working wavelength of the band-pass filter in the channel light path one is 2.0 μm to 2.2 μm, and the center wavelength is 2.1 μm. The working wavelength of the band-pass filter in the channel light path two is 2.2 μm to 2.4 μm, and the center wavelength is 2.3 μm. Each mounting lens barrel can be independently disassembled.

8. The dual-channel optical path splitting system based on the colorimetric temperature measurement principle according to claim 1, characterized in that, Each single-waveband focusing lens group corresponds to an infrared detector, which is a short infrared wave InGaAs detector with refrigeration function.

9. The dual-channel optical path splitting system based on the colorimetric temperature measurement principle according to claim 2, characterized in that, The light beam collector is in a barrel-shaped structure as a whole, the inner wall of which is a threaded curved surface, and the bottom is equipped with a conical reflecting device opposite to the barrel mouth; when the incident light is transmitted to the inside of the light beam collector via the barrel mouth, it will first be reflected on the surface of the conical reflecting device, and then be transmitted to the threaded curved surface, and after reaching the threaded curved surface, it will be reflected to the surface of the conical device again, and after multiple reflections, the energy of the incident stray light will gradually attenuate, so as to achieve the absorption of the stray light.

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