Multi-channel gas concentration detection system

Abstract

The invention discloses a multichannel gas concentration detection system, and relates to the field of gas concentration detection. A light inlet and a light outlet are formed in the side wall of the absorption cell, and a first reflection piece and a second reflection piece which are oppositely arranged are arranged in the absorption cell; the rotary scanning piece is arranged on the outer side of the light outlet, and a plurality of mounting grooves are formed in the circumferential direction; the detection unit comprises a light modulation part and a detection part; wherein the light beam is reflected for multiple times between the first reflection piece and the second reflection piece and then is emitted out from the light outlet to form a detection light field, and the multiple detection pieces scan different space areas of the detection light field in the rotation process. By the adoption of the scheme, the defect that only local concentration information can be obtained through traditional detection is overcome, the real gas concentration distribution condition of the whole cavity can be accurately reflected, and multi-channel real-time parallel detection can be achieved in a limited space.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas concentration detection, and in particular to a multi-channel gas concentration detection system. BACKGROUND

[0002] In the semiconductor manufacturing process, vapor deposition processes such as chemical vapor deposition, metal organic chemical vapor deposition, and atomic layer deposition all require accurate monitoring of reaction gases and byproduct gases to ensure process stability and yield. Therefore, gas detection equipment is widely used in semiconductor process chambers, pipeline and environmental monitoring links to detect and monitor the concentration of multi-component gases in real time. In these applications, the detection equipment not only needs to have high sensitivity, but also needs to consider response speed and system stability to meet the high requirements in complex process environments.

[0003] At present, common gas concentration detection technologies mainly use optical methods such as non-dispersive infrared, tunable diode laser absorption spectroscopy, or Fourier transform infrared spectroscopy. However, these traditional technical solutions have obvious limitations when facing simultaneous detection of multi-component gases: in a semiconductor process chamber, due to the non-uniformity of gas flow, temperature and reaction process, the gas concentration often has a significant gradient in spatial distribution. The traditional single-point or static area detection method can only obtain local concentration information, and it is difficult to accurately reflect the true gas concentration of the entire chamber cross section, resulting in systematic errors in the measurement results, which cannot meet the stringent requirements of high-end processes on monitoring accuracy. At the same time, although the existing system attempts to achieve multi-channel measurement through time switching, the serial sampling mechanism essentially limits the system response speed, making it difficult to achieve truly high-speed multi-component parallel acquisition and processing.

[0004] Therefore, how to realize multi-channel real-time synchronous detection in limited space, accurately reflect the true gas concentration of the entire chamber cross section, and avoid measurement errors caused by uneven spatial distribution of gas has become a technical problem that needs to be solved. SUMMARY

[0005] The purpose of the present application is to provide a multi-channel gas concentration detection system to solve the technical problem of how to realize multi-channel real-time synchronous detection in limited space, accurately reflect the true gas concentration of the entire chamber cross section, and avoid measurement errors caused by uneven spatial distribution of gas in the prior art.

[0006] To achieve the above-mentioned purpose, the technical solution of the present application is as follows: A multi-channel gas concentration detection system, comprising: a light source; an absorption cell, the side wall is provided with an entrance light port and an exit light port, the entrance light port is used for receiving the light beam emitted by the light source, and the absorption cell is provided with a first reflecting element and a second reflecting element arranged oppositely; A rotating scanning member is arranged outside the light outlet and has a plurality of mounting slots formed in the circumferential direction; A multi-channel detection assembly includes a plurality of detection units arranged on the rotating scanning member, the detection units being arranged in correspondence with the mounting slots respectively, each detection unit including a light modulation member embedded in the corresponding mounting slot and a detection member for receiving a light signal and converting it into an electrical signal, the light modulation member being used for filtering light of a specific wavelength; A driving assembly is used for driving the rotating scanning member and the multi-channel detection assembly to rotate around a rotation axis; The light beam is reflected multiple times between the first and second reflecting members and then emitted from the light outlet to form a detection light field, and the plurality of detection members sweep through different spatial regions of the detection light field during rotation.

[0007] Further, the driving assembly includes: A first driving member, the output end of which is connected with the rotating scanning member, is used for driving the rotating scanning member to rotate around the rotation axis; A second driving member, the output end of which is connected with the plurality of light modulation members, is used for driving the plurality of light modulation members to rotate around the rotation axis; When the first driving member is working, the second driving member locks the light modulation members; when the second driving member is working, the first driving member locks the rotating scanning member.

[0008] Further, the rotating scanning member includes coaxially arranged and relatively rotatable first and second rotating discs; the plurality of detection members are fixedly arranged along the circumference of the first rotating disc; the mounting slots are formed in the second rotating disc; the first driving member is used for driving the first rotating disc to rotate around the rotation axis, and the second driving member is used for driving the second rotating disc to rotate around the rotation axis.

[0009] Further, the rotation axis is parallel to the central axis of the light outlet, and the plurality of mounting slots are uniformly distributed along the circumference of the rotating scanning member.

[0010] Further, the mounting slots are through holes, the light modulation members include light filters embedded in the through holes, and the detection members are pyroelectric detection elements, the sensing surface of each pyroelectric detection element being arranged opposite to the light filter.

[0011] Further, the first and second reflecting members are plano-concave spherical mirrors, the concave surfaces of the first and second reflecting members are arranged opposite to each other and coaxially in the absorption cell; and optical windows serving as the light inlet and light outlet are formed in the first and second reflecting members respectively.

[0012] Further, a focusing lens group is arranged on the light path between the light source and the light inlet, for focusing the light beam emitted by the light source and coupling it to the light inlet.

[0013] Further, a multi-dimensional adjusting frame is arranged, and the focusing lens group is mounted on the multi-dimensional adjusting frame, and the deflection angle of the focusing lens group relative to the light inlet is adjusted through the multi-dimensional adjusting frame.

[0014] By using the above technical scheme, the multi-dimensional adjusting frame is used to change the initial incidence angle of the light beam entering the absorption cell, so as to adjust the reflection times of the light beam between the first reflecting element and the second reflecting element, and then adjust the optical path, so that the gas and the light are in sufficient contact, and the detection precision is improved.

[0015] Further, an expansion collimation element is arranged between the light outlet and the rotary scanning element; the expansion collimation element comprises a negative lens and a positive lens arranged in sequence along the light path, for converting the divergent light beam emitted through the light outlet into a collimated light beam with expanded diameter and parallel to the rotary axis, and irradiating the light modulation element on the rotary scanning element.

[0016] Further, a high-reflection dielectric film is coated on the concave surface of the first reflecting element and the second reflecting element, and the high-reflection dielectric film is a periodic multi-layer dielectric film based on a material.

[0017] Further, the distance between the first reflecting element and the second reflecting element is 170mm-190mm.

[0018] The multi-channel gas concentration detection system provided by the application has the following advantages: the first reflecting element and the second reflecting element are arranged in the absorption cell, so that the light beam forms a stable detection light field after multiple reflections in the absorption cell, the path length of the light and the gas to be detected is increased, and the detection sensitivity is significantly improved; the rotary scanning element is arranged outside the light outlet, and a plurality of detection units are arranged circumferentially on the rotary scanning element, so that the detection units can cover different spatial regions of the detection light field in turn during rotation, synchronous acquisition and comparative analysis of a plurality of positions in the cross section of the chamber are realized, the shortcomings of the traditional detection that can only obtain local concentration information are overcome, and the real gas concentration distribution of the entire chamber can be accurately reflected; at the same time, the rotary scanning structure avoids the response speed limitation caused by the traditional multi-channel serial sampling, and can realize multi-channel real-time parallel detection in a limited space, thereby improving the detection efficiency and system response speed; in addition, the selective transmission of the light modulation element to specific wavelengths further enhances the identification ability of the target gas component, effectively reduces the interference signal, and improves the detection precision of multiple components. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1A structural schematic diagram of a multi-channel gas concentration detection system according to an embodiment of the present application; Figure 2 A light path diagram of a multi-channel gas concentration detection system according to an embodiment of the present application; Figure 3 A structural schematic diagram of an absorption cell according to an embodiment of the present application; Figure 4 A structural sectional view of a detection unit and a driving assembly according to an embodiment of the present application; Figure 5 A structural schematic diagram of a four-channel according to an embodiment of the present application; Figure 6 A structural schematic diagram of a six-channel according to an embodiment of the present application.

[0020] Reference signs: 1, light source; 2, absorption cell; 21, light inlet; 22, light outlet; 23, first reflecting member; 24, second reflecting member; 3, rotating scanning member; 31, first rotating disc; 32, second rotating disc; 33, rotating axis; 4, detection unit; 41, light modulating member; 42, detection member; 44, amplifier; 45, oscilloscope; 46, controller; 5, first driving member; 6, second driving member; 7, focusing lens group; 8, multi-dimensional adjusting frame; 9, beam expanding and collimating member. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts should fall within the scope of the present application. Unless otherwise defined, the technical terms or scientific terms used herein should be understood as their common meanings to those of ordinary skill in the art to which the present application belongs. The words such as “comprise” and the like used herein mean that the elements or objects before the words encompass the elements or objects listed after the words and their equivalents, and do not exclude other elements or objects.

[0022] The above description will be further illustrated by the following Figure 1 The above description will be further illustrated by the following Figure 6 , and the specific embodiments of the present application will be further described in detail.

[0023] Reference will now be made to the drawings and embodiments illustrated in the drawings. Figures 1-3In some embodiments of the present application, as shown in the figure, a multi-channel gas concentration detection system includes a light source 1, an absorption cell 2, a rotating scanning element 3, a multi-channel detection assembly, and a driving assembly. The light source 1 is used to generate a light beam required for detection, which enters the absorption cell 2 after being regulated by an optical path. The absorption cell 2 is provided with an air inlet and an air outlet, and is designed to be airtight except for the air inlet and the air outlet. The light source is a broadband far-infrared light source with a wavelength range of 2 μm to 17 μm. An optical window is provided on the side wall of the absorption cell 2 as a light inlet 21 and a light outlet 22, wherein the light inlet 21 is used to receive the light beam emitted by the light source 1, and the absorption cell 2 is internally provided with a first reflecting element 23 and a second reflecting element 24 arranged oppositely, whose concave surfaces are oppositely placed and coaxially.

[0024] In some specific embodiments of the present application, the first reflecting element 23 and the second reflecting element 24 are plano-concave lenses, and a high-reflection medium film with a coverage rate of more than 98% is coated on the concave surface of the plano-concave lens. The medium film can be composed of a periodic multilayer film system of and the like. It should be noted that the light inlet 21 and the light outlet 22 are fully transparent regions and are not coated with a reflecting film. Through the application of the high-reflection film, the reflection efficiency of the light beam in the absorption cell 2 can be significantly improved, and the light loss can be reduced, thereby further enhancing the light gas effect and improving the detection accuracy of the system.

[0025] In some embodiments of the present application, after the incident light beam enters the absorption cell 2, it is reflected back and forth between the first reflecting element 23 and the second reflecting element 24 for multiple times, thereby forming a detection light field with a larger coverage range. By prolonging the propagation path of the light in the gas, the optical path length can be significantly increased, the interaction between the gas molecules and the light can be enhanced, and the sensitivity of the gas concentration detection can be improved. In some other embodiments of the present application, the present application is based on Non-dispersive Infra-red. The absorption rate of the gas is proportional to the optical path. By prolonging the effective absorption distance, the interaction between the gas molecules and the laser can be enhanced, the absorption signal amplitude can be improved, and the measurement sensitivity and detection accuracy of the system can be significantly improved.

[0026] However, in actual design, if the length of the absorption cell 2 is too short, although the optical path can be increased by adjusting the incident angle, the light beams are too dense in the limited space, which is easy to produce optical interference fringes, and the distribution of the reflected light spots is compact, resulting in that the effective area of the mirror surface is not fully utilized. On the contrary, when the length of the absorption cell 2 is too large, although there is enough space, the light beams are relatively sparse in the reflection process, the number of reflections is reduced, the total optical path is insufficient, and the effective utilization rate of the mirror surface is also low. Therefore, in the design of the absorption cell 2, the factors of avoiding excessive optical interference, maintaining uniform light spot distribution, and ensuring that the incident light and the outgoing light have a reasonable angle are considered, and an absorption cell 2 scheme that takes into account the optical performance and structural size is selected to improve the optical path and utilization rate while avoiding optical interference fringes and improving the detection accuracy. Specifically, the single-pass length of the absorption cell is between 170mm and 190mm, and is preferably 180mm, at which time the number of reflections is 62 times, and the total optical path is as long as 11.45m.

[0027] In some specific embodiments of the present application, a rotating scanning piece 3 is arranged outside the light outlet 22, and a plurality of installation grooves are formed in the rotating scanning piece 3 in the circumferential direction. A multi-channel detection assembly is installed on the rotating scanning piece 3, and the detection assembly includes a plurality of detection units 4 corresponding to the installation grooves. Each detection unit 4 is composed of a light modulation piece 41 and a detection piece 42. The light modulation piece 41 can be a filter embedded in the through hole of the installation groove, and the filter can selectively transmit light signals of a specific wavelength, thereby realizing wavelength differentiation and screening of specific gas components. The detection piece 42 preferably adopts a pyroelectric detection element, and its sensing surface is arranged opposite to the filter, for receiving the light signals transmitted through the filter and converting them into electrical signals. With the rotation of the rotating scanning piece 3 around the rotation axis 33, the plurality of detection units 4 can successively scan different spatial regions of the detection light field, thereby realizing multi-point detection of a plurality of positions in the cross section of the chamber, and further obtaining more comprehensive and real gas concentration distribution information.

[0028] In some specific embodiments of the present application, the detection unit 4 further includes an amplifier 44, an oscilloscope 45 and a controller 46. The pyroelectric detection element is electrically connected to the amplifier 44, for converting the received light signals into electrical signals and performing amplification processing; the amplifier 44 is electrically connected to the controller 46, so that the controller 46 further processes and analyzes the amplified signals; at the same time, the oscilloscope 45 is electrically connected to the pyroelectric detection element, for displaying the electrical signal waveform generated by the detection element in real time. In this way, after the light beam undergoes multiple reflections in the absorption cell 2, its light intensity is attenuated due to the absorption effect, and the pyroelectric detection element can accurately detect the change of the light intensity with the wavelength and generate corresponding electrical signals. The electrical signals are collected and displayed by the oscilloscope 45, thereby obtaining a complete absorption curve including the non-absorption segment and the absorption peak segment, which provides a reliable basis for subsequent concentration calculation and quantitative analysis.

[0029] In some other embodiments of the present application, the controller 46 is also electrically connected with the light source 1 to realize dynamic control of the output state of the light source 1. For example, the controller 46 can adjust the emission power, working frequency or pulse width of the light source 1 according to the detection requirement to optimize the matching of the optical signal between the light source 1 and the absorption cell 2; at the same time, it can also cooperate with the driving motor of the rotating scanning member 3 or the light filtering member to realize the synchronous control of the light source 1 modulation and the light path switching, so as to further improve the response speed and detection accuracy of the system in the detection of multi-component gas.

[0030] In some other embodiments of the present application, the detection member 42 can be selected from a photodiode array, a quantum cascade detector or a photoacoustic detector in addition to the pyroelectric detection element. These different types of detection members can be selected according to the spectral characteristics of the detected gas and the target sensitivity requirement. Among them, the photodiode array has a higher response speed in the visible light to near-infrared waveband, which is suitable for high-speed signal acquisition; the quantum cascade detector has excellent detection sensitivity in the mid-infrared region, which is suitable for detecting gases with obvious mid-infrared absorption characteristics; and the photoacoustic detector can indirectly represent the absorption characteristics through acoustic signals.

[0031] In some specific embodiments of the present application, the light modulation member 41 can be a grating or a tunable micro filter (such as a MEMS micro filter) in addition to the optical filter. The grating can realize wavelength separation in a wide waveband range, and the tunable filter can dynamically change its transmission wavelength, so as to realize flexible multi-component gas detection. In some specific embodiments of the present application, in order to further improve the sampling efficiency of the system, the rotation mode of the rotating scanning member 3 can be continuous rotation or step rotation. In the continuous rotation mode, the detection unit 4 can perform high-speed scanning on the detection light field, which is suitable for real-time monitoring of rapidly changing gas concentration; in the step rotation mode, the detection unit 4 can keep stable sampling at a certain spatial position, which is convenient for realizing high-precision fixed-point detection.

[0032] In some embodiments of the present application, the driving assembly comprises a first driving member 5 and a second driving member 6. The output end of the first driving member 5 is connected with the rotating scanning member 3 for driving the rotating scanning member 3 to rotate around the rotation axis 33, realizing the circumferential scanning of the detection light field. The output end of the second driving member 6 is connected with the plurality of light modulation members 41 for driving the light modulation members 41 to rotate independently or switch the working state. In the specific working process, when the first driving member 5 is started, the second driving member 6 is in the locked state, the light modulation members 41 remain fixed, and the detection members 42 rotate synchronously with the rotating scanning member 3, thereby realizing the rapid area scanning of different spatial regions of the cavity. When the second driving member 6 is started, the first driving member 5 remains locked, the rotating scanning member 3 remains unchanged, and the light modulation members 41 can be independently adjusted in wavelength selectivity, thereby realizing the accurate differentiation and detection of specific gas components. Through the cooperative action of the double driving members, the system has both the large-range rapid scanning capability and the flexible spectral regulation function, effectively improving the parallel detection capability and detection precision of multi-component gas.

[0033] In some other embodiments of the present application, the first driving member 5 and the second driving member 6 can also adopt different driving modes for optimization. Among them, the first driving member 5 can adopt a step motor or a servo motor to realize high-speed continuous scanning or high-precision step scanning; the second driving member 6 can adopt a piezoelectric driver, a micro electromagnetic driver or a micro driver to realize the rapid switching of the light modulation members 41. Further, in some parallel implementation schemes, the double driving members can be replaced by an integrated driving module, which simultaneously controls the rotating scanning member 3 and the light modulation members 41 through a differential transmission mechanism, reducing the system complexity and improving the stability of the driving.

[0034] Referring to Figure 4 In some other embodiments of the present application, the rotating scanning member 3 comprises a first rotating disc 31 and a second rotating disc 32 arranged coaxially, which can rotate independently. The plurality of detection members 42 are fixed along the circumference of the first rotating disc 31, and the plurality of mounting grooves are arranged on the second rotating disc 32. In this way, the first driving member 5 can be used to drive the first rotating disc 31 to rotate, and the second driving member 6 can be used to drive the second rotating disc 32 to rotate, so that the detection members 42 and the light modulation members 41 can work in different rotating modes. This structure makes the relative position between the detection members 42 and the light modulation members 41 controllable, facilitating the combined detection of different wavelengths and different spatial positions.

[0035] In some embodiments of the present application, the design of the rotating scanning member 3 and the driving assembly takes into account the working requirements of both high-precision spatial scanning mode and multi-component time-division multiplexing mode. In the high-precision spatial scanning mode, the first rotating disc 31 is rotated as the scanning main body, so that each detection unit 4 sequentially scans different spatial positions of the detection light field along the circumference, thereby achieving multi-point and synchronous sampling of the cross section of the chamber. The second rotating disc 32 is locked or stationary relative to the first rotating disc 31 in this mode. The first driving member 5 is a micro servo motor in some embodiments of the present application, which drives the first rotating disc 31 to rotate; the second driving member 6 is switched to a "relative locking / braking" state. The second driving member 6 can be an electromagnetic brake or a mechanically integrated claw lock, constant force spring lock, etc. in some specific embodiments of the present application. In addition, to ensure angle positioning and data alignment, the first driving member 5 and the second driving member 6 are equipped with high-resolution encoders, such as high-resolution incremental encoders, which correspond the sampling time points to the encoder angle positions in the controller 46, so as to achieve accurate mapping of spatial positions and sampling data. Specifically, each channel is equipped with an independent detection unit 4 and continuously works in the physical layer, so that all detection units 42 collect the signals received at their respective time points in parallel during the rotation, forming a time-space sample set covering the entire cross section. Compared with the time sequence sampling of a single detector in the prior art, the parallel architecture of the present application significantly improves the effective sampling rate of the system. In some other embodiments of the present application, the second rotating disc 32 is a filter wheel.

[0036] In the multi-component time-division multiplexing mode, the first rotating disc 31 is locked, and only the second rotating disc 32 is driven to rotate and switch different light modulation members 41. In this way, each detection unit 42, which includes a pyroelectric detection element in some embodiments of the present application, becomes an independent and switchable wavelength detection structure, and all detection units 42 collect different wavelengths in parallel at their respective sampling positions, thereby achieving rapid and parallel time-division detection of multiple gas components. In addition, although the wavelengths are switched in time division, all positions are collected in parallel because each detection unit 42 is always working at the same time, and only the wavelength channels are rotated in time, thereby effectively improving the overall detection throughput. The upper limit of the switching rate is determined by the rotation speed of the filter wheel, the stabilization time of the filter, and the response time of the pyroelectric detection element.

[0037] Referring to Figure 5 and Figure 6 , the number of channels is four, six or eight. In some embodiments of the present application, the gas to be measured in the absorption cell is one or more of SIF4, CF4, WF6, TiF4, CuF2, AlF2, CoF2 and TaF5.

[0038] In some embodiments of the present application, the system further comprises a focusing lens group 7 arranged on the light path between the light source 1 and the light inlet 21, for collimating and focusing the light beam emitted by the light source 1, so that it can be efficiently coupled into the light inlet 21, thereby ensuring stable transmission of light energy. In order to achieve precise light path control, the focusing lens group 7 is installed on a multi-dimensional adjustment frame 8, which can provide multi-dimensional adjustment functions including horizontal and vertical translation, as well as pitch and yaw angles. The operator can accurately adjust the position and angle of the lens group through the adjustment frame, thereby flexibly changing the initial incident angle of the light beam when it enters the absorption cell 2. The above design not only effectively controls the number of reflections of the light beam between the first reflecting member 23 and the second reflecting member 24, but also flexibly adjusts the optical path length according to different detection requirements, to adapt to the detection sensitivity requirements of different gas components. By adjusting the deflection angle of the focusing lens group 7, the slight deviation caused by installation tolerance or long-term use in the light path can be compensated to some extent, ensuring that the light beam enters the absorption cell 2 stably and maintains the spot shape without distortion. At the same time, this structure can be compatible with multiple light source 1 specifications and different cavity sizes.

[0039] In some embodiments of the present application, the multi-dimensional adjustment frame 8 can use high-precision fine adjustment mechanisms or electric control modules to achieve repeatable and automated adjustment control of the light path incident angle, which not only reduces the difficulty of manual operation, but also improves the overall reliability of the system.

[0040] In some other embodiments of the present application, a beam expanding and collimating member 9 is added between the light outlet 22 and the rotating scanning member 3. The beam expanding and collimating member 9 can be composed of negative and positive lenses in sequence, which converts the divergent light beam emitted from the light outlet 22 into a collimated light beam with an enlarged diameter, and ensures that its propagation direction is parallel to the rotation axis 33. Through this structure, the coverage range of the light beam can be effectively improved, ensuring that the probe light field can be fully collected by multiple detection units 4, and improving the uniformity and stability of detection.

[0041] In some other embodiments of the present application, different light sources 1 can also be used for different application environments, such as broadband infrared light sources 1 or tunable semiconductor lasers, to adapt to the absorption characteristics of different gas components; in addition to pyroelectric detection elements, the detection member 42 can also use photodiode arrays, quantum cascade detectors, etc., to improve the response speed or sensitivity in a specific waveband. In addition, the rotating scanning member 3 is not limited to mechanical driving, and can also be realized through an optical switch array or a MEMS micro-mirror array, thereby completing multi-channel fast switching and scanning detection without increasing mechanical complexity.

[0042] The application further discloses an electronic device (not shown in the figure) used for analyzing and training gas concentration signals of different cross-section regions collected by a plurality of pyroelectric detection elements, so as to facilitate adjustment of a gas conveying rate and a conveying amount, and avoid uneven gas concentration in the absorption cell 2, thereby affecting the measurement accuracy. The electronic device can include one or more central processing units (CPUs), a memory, a display, one or more graphics processing units (GPUs), and a system running on the electronic device. The system is stored in the memory and is configured to run on the one or more processors and the one or more GPUs. The memory stores local data, and the local data is configured to train the one or more processors and the one or more GPUs.

[0043] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixing", and the like should be understood in a broad sense, for example, "fixing" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be internal communication of two elements or interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] In addition, if the present application embodiments involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the protection scope of the present application.

[0045] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited to this, any change or replacement within the technical scope disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A multi-channel gas concentration detection system, characterized in that, include: Light source (1); The absorption cell (2) has a light inlet (21) and a light outlet (22) on its side wall. The light inlet (21) is used to receive the light beam emitted by the light source (1). The absorption cell (2) has a first reflector (23) and a second reflector (24) arranged opposite to each other. A rotating scanning component (3) is disposed outside the light outlet (22) and has multiple mounting slots along the circumference; The multi-channel detection assembly includes multiple detection units (4) disposed on the rotating scanning component (3). The detection units (4) are respectively disposed in relation to the mounting slots. Each detection unit (4) includes an optical modulator (41) embedded in the corresponding mounting slot and a detection component (42) for receiving optical signals and converting them into electrical signals. The optical modulator (41) is used to filter light of a specific wavelength. A driving component is used to drive the rotating scanning component (3) and the multi-channel detection component to rotate around a rotation axis (33); The light beam is reflected multiple times between the first reflector (23) and the second reflector (24) and then emitted from the light outlet (22) to form a detection light field. Multiple detection elements (42) sweep across different spatial regions of the detection light field during rotation.

2. The multi-channel gas concentration detection system according to claim 1, characterized in that, The driving component includes: The first driving component (5) has its output end connected to the rotating scanning component (3) and is used to drive the rotating scanning component (3) to rotate around the rotation axis (33); The second driving unit (6) has its output end connected to the plurality of optical modulators (41) for driving the plurality of optical modulators (41) to rotate around the rotation axis (33); When the first driving member (5) is working, the second driving member (6) locks the light modulator (41); when the second driving member (6) is working, the first driving member (5) locks the rotating scanning member (3).

3. The multi-channel gas concentration detection system according to claim 2, characterized in that, The rotating scanning component (3) includes a first rotating disk (31) and a second rotating disk (32) that are coaxially arranged and can rotate relative to each other; a plurality of the detection components (42) are fixedly arranged in a circumferential array along the first rotating disk (31); the mounting groove is opened on the second rotating disk (32); the first driving component (5) is used to drive the first rotating disk (31) to rotate around the rotation axis (33), and the second driving component (6) is used to drive the second rotating disk (32) to rotate around the rotation axis (33).

4. The multi-channel gas concentration detection system according to claim 1, characterized in that, The rotation axis (33) is parallel to the central axis of the light outlet (22), and the plurality of mounting slots are evenly distributed along the circumference of the rotating scanning component (3).

5. The multi-channel gas concentration detection system according to claim 1, characterized in that, The mounting slot is a through hole, the optical modulation element (41) includes a filter embedded in the through hole, and the detection element (42) is a pyroelectric detector element, with the sensing surface of the pyroelectric detector element facing the filter.

6. The multi-channel gas concentration detection system according to claim 1, characterized in that, The first reflector (23) and the second reflector (24) are plano-concave spherical reflectors. The concave surfaces of the first reflector (23) and the second reflector (24) are opposite each other and are arranged in the absorption cell (2) with the same optical axis. Optical windows, which serve as the light inlet (21) and the light outlet (22), are respectively opened on the first reflector (23) and the second reflector (24).

7. The multi-channel gas concentration detection system according to claim 1, characterized in that, It also includes a focusing lens group (7), which is disposed in the optical path between the light source (1) and the light inlet (21) to focus the light beam emitted by the light source (1) and couple it to the light inlet (21).

8. The multi-channel gas concentration detection system according to claim 7, characterized in that, It also includes a multi-dimensional adjustment frame (8), on which the focusing lens group (7) is mounted, and the deflection angle of the focusing lens group (7) relative to the light inlet (21) is adjusted by the multi-dimensional adjustment frame (8).

9. The multi-channel gas concentration detection system according to claim 1, characterized in that, A beam expander and collimator (9) is also provided between the light outlet (22) and the rotating scanning element (3); the beam expander and collimator (9) includes a negative lens and a positive lens arranged sequentially along the optical path, which are used to convert the diverging light beam emitted through the light outlet (22) into a collimated light beam with an enlarged diameter and parallel to the rotation axis (33), and irradiate the light modulator (41) on the rotating scanning element (3).

10. A multi-channel gas concentration detection system according to claim 1, characterized in that, The concave surfaces of the first reflector (23) and the second reflector (24) are coated with a high-reflectivity dielectric film, wherein the high-reflectivity dielectric film is based on... Periodic multilayer dielectric films of materials.

11. A multi-channel gas concentration detection system according to claim 1, characterized in that, The distance between the first reflector (23) and the second reflector (24) is 170mm~190mm.

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