Optical detection assembly

Abstract

The invention discloses an optical detection assembly, and relates to the technical field of gas detection.The optical detection assembly is applied to a gas chamber structure, the gas chamber structure is provided with a gas cavity, the gas cavity is filled with gas, and the optical detection assembly comprises a laser emitter arranged in the gas chamber structure and used for emitting laser beams towards the gas cavity; the laser receiver is arranged in the air chamber structure and is opposite to the laser transmitter; the lens module is arranged between the laser transmitter and the laser receiver, and the lens module is used for receiving the light beams transmitted by the laser transmitter, condensing the light beams and transmitting the light beams to the laser receiver; wherein the incident light surface of the lens module and the emitting light surface of the laser emitter are arranged in a mutually inclined manner, so that laser reflected by the incident light surface of the lens module deviates from the laser emitter. According to the technical scheme provided by the invention, the laser is prevented from being reflected back to the laser transmitter, the accuracy of a detection result is improved, and the laser transmitter is prevented from being burnt.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of detection, in particular to an optical detection assembly. BACKGROUND

[0002] In the technical field of gas detection, generally based on the selective absorption characteristics of gas molecules to specific wavelength laser, high sensitivity detection of target gas concentration in the environment is realized. If there is a certain gas in the environment, the laser passes through the chamber or environment containing the gas, and the gas molecules will absorb the laser photons matching the characteristic absorption spectrum, resulting in attenuation of the transmitted light intensity. The higher the gas concentration, the stronger the absorption, and the more serious the light intensity attenuation. By comparing the laser intensity before and after gas absorption, the gas concentration in the chamber or environment can be obtained.

[0003] In the existing structure, in order to ensure that the laser is transmitted from the emitter to the receiver, a lens is generally used to focus the laser beam emitted by the laser emitter to the laser receiver. The entrance surface of the lens reflects the received laser emitted by the laser emitter while refracting. When the reflected light is reflected to the laser emitter, it may cause high-order mode and other problems, affecting the accuracy of the gas concentration detection result, and even long duration may burn the laser emitter, affecting the service life.

[0004] Similarly, when detecting the concentration of dust and other micro-particles in the gas, although the dust concentration in the gas is detected by dust scattering laser, the above similar mode instability problem may also be encountered, resulting in inaccurate dust concentration detection result. SUMMARY

[0005] The main purpose of the present application is to provide an optical detection assembly, which aims to solve the technical problem of lens reflecting laser to laser emitter affecting the accuracy of gas concentration detection.

[0006] To achieve the above purpose, the optical detection assembly provided by the present application is applied to a gas chamber structure, the gas chamber structure has a gas cavity, the gas cavity is filled with gas, and the optical detection assembly comprises:

[0007] A laser emitter is arranged in the gas chamber structure, and the laser emitter is used for emitting a light beam towards the gas cavity; A laser receiver is arranged in the gas chamber structure and arranged opposite to the laser emitter; A lens module is arranged between the laser emitter and the laser receiver, and the lens module is used for receiving the light beam emitted by the laser emitter and condensing the light beam towards the laser receiver for emission; The incident light surface of the lens module is arranged to be inclined to the emitting light surface of the laser emitter, so that the laser reflected by the incident light surface of the lens module deviates from the laser emitter.

[0008] In an embodiment, the lens module comprises: a first lens arranged close to the laser emitter, and the incident light surface of the first lens is arranged to be inclined to the emitting light surface of the laser emitter; a second lens arranged between the first lens and the laser receiver and arranged close to the laser receiver.

[0009] In an embodiment, the emitting light surface of the laser emitter is arranged to be non-perpendicular to the optical axis direction of the light beam after converging by the lens module; and / or, the detecting light surface of the laser receiver is arranged to be non-perpendicular to the optical axis direction of the light beam after converging by the lens module.

[0010] In an embodiment, when the emitting light surface of the laser emitter is arranged to be non-perpendicular to the optical axis direction of the light beam after converging by the lens module, at least one of the incident light surface and the emitting light surface of the first lens is a free-form surface; and / or, when the detecting light surface of the laser receiver is arranged to be non-perpendicular to the optical axis direction of the light beam after converging by the lens module, at least one of the incident light surface and the emitting light surface of the second lens is a free-form surface.

[0011] In an embodiment, the air chamber comprises a first substrate having a first mounting surface facing the laser emitter, the first mounting surface is arranged to be inclined, and the emitting light surface of the laser emitter is parallel to the first mounting surface, so that the emitting light surface of the laser emitter is arranged to be non-perpendicular to the optical axis direction of the light beam after collimating by the first lens; and / or, the air chamber comprises a second substrate having a second mounting surface facing the laser receiver, the second mounting surface is arranged to be inclined, and the detecting light surface of the laser receiver is parallel to the second mounting surface, so that the detecting light surface of the laser receiver is arranged to be non-perpendicular to the optical axis direction of the light beam after collimating by the first lens.

[0012] In an embodiment, the first lens comprises an optical part for light processing, the emitting light surface of the laser emitter is arranged to be perpendicular to the optical axis direction of the light beam after converging by the lens module, one end of the optical part is inclined, and the curvature of the reflecting light surface of the optical part away from the one end of the laser emitter is greater than the curvature of the one end close to the laser emitter.

[0013] In an embodiment, the divergence angle of the laser emitted by the laser emitter is 2a degrees, one end of the optical part is inclined, so that the incident light surface of the optical part is inclined relative to the laser emitter to form an inclination angle of β degrees, and the inclination angle and the divergence angle of the laser emitted by the laser emitter have a relationship of β>a.

[0014] In an embodiment, the receiving full angle of the second lens is greater than or equal to the divergence full angle of the first lens.

[0015] In an embodiment, the inner wall of the gas chamber structure is provided with a light-absorbing coating. And / or, the inner wall of the gas chamber structure is black resin or black film layer.

[0016] In an embodiment, the inner wall of the gas chamber structure is provided with a sawtooth structure.

[0017] In the technical scheme of the present application, the laser emitter and the laser receiver are respectively arranged on the opposite sides of the inner wall of the gas chamber, the first lens is arranged between the laser emitter and the laser receiver, the first lens is arranged close to the laser emitter, the laser emitter is oriented to emit a laser beam towards the inside of the gas chamber, the incident light surface of the first lens is close to the laser emitter and receives all the light beams emitted by the laser emitter, and the divergent laser beam is converted into a convergent light beam to be emitted towards the laser receiver. The gas concentration is calculated by analyzing the light intensity received by the laser receiver and the laser intensity emitted by the laser emitter according to the Beer-Lambert law, and the incident light surface of the first lens and the emitting surface of the laser emitter are arranged to be inclined to each other, so that when the laser emitter emits laser towards the first lens, the laser reflected by the incident light surface of the first lens deviates from the laser emitter, thereby preventing the laser from being reflected back to the laser emitter, avoiding burning the laser emitter, improving the service life of the device, and also avoiding affecting the laser emitted by the laser emitter, improving the accuracy of the laser detection result. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to the structures shown in these drawings without creative labor.

[0019] Figure 1 The structure diagram of the first embodiment of the optical detection assembly provided by the present application; Figure 2 The structure diagram of the second embodiment of the optical detection assembly provided by the present application; Figure 3Structure schematic view of the third embodiment of the optical detection assembly provided by the present application; Figure 4 Structure schematic view of the fourth embodiment of the optical detection assembly provided by the present application; Figure 5 Structure schematic view of the fifth embodiment of the optical detection assembly provided by the present application; Figure 6 Structure schematic view of the sixth embodiment of the optical detection assembly provided by the present application; Figure 7 Schematic view of the relationship between the first lens inclination angle and the laser emitter divergence angle in the optical detection assembly provided by the present application; Figure 8 Structure schematic view of the first lens in the optical detection assembly provided by the present application.

[0020] Explanation of the reference signs: 10, air chamber; 101, air cavity; 11, first substrate; 12, second substrate; 20, data processing module; 100, laser emitter; 200, lens module; 210, first lens; 211, connecting part; 212, optical part; 220, second lens; 300, laser receiver.

[0021] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0023] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture, and if the certain posture changes, the directional indications will also change accordingly.

[0024] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0025] In the field of gas detection technology, the selective absorption characteristics of gas molecules to specific wavelengths of laser light are usually used to achieve highly sensitive detection of the concentration of target gas in the environment. If a certain gas is present in the environment, when the laser passes through the chamber or environment containing the gas, the gas molecules will absorb the laser photons that match its characteristic absorption spectrum, resulting in attenuation of the transmitted light intensity. The higher the gas concentration, the stronger the absorption and the more severe the light intensity attenuation. The attenuated light signal is then received by a laser receiver, and the laser intensity before and after gas absorption is compared to determine the gas concentration in the chamber or environment.

[0026] In existing structures, to ensure that the laser is transmitted from the transmitter to the receiver, a lens is generally used to focus the laser beam emitted by the laser transmitter onto the laser receiver. The incident light surface of the lens refracts and reflects the received laser at the same time. When the reflected light is reflected back to the laser transmitter, it will cause problems such as higher-order modes, resulting in lasers of other frequencies or wavelengths, which will affect the accuracy of gas concentration detection results. In fact, if this continues for a long time, it will burn the laser transmitter and affect its service life.

[0027] Similarly, when detecting the concentration of dust and other microparticles in a gas, although the dust concentration is detected by dust scattering laser, the same instability problem mentioned above can be encountered, leading to inaccurate dust concentration detection results.

[0028] This invention proposes an optical detection component.

[0029] Please see Figure 1 and Figure 2 In one embodiment of the present invention, the optical detection component is applied to a gas chamber 10 structure, the gas chamber 10 structure having a gas cavity 101 filled with gas, and the optical detection component includes: The laser transmitter 100 is arranged in the air chamber 10 structure, and is used for emitting a laser beam towards the air cavity 101. The laser receiver 300 is arranged in the air chamber 10 structure, and is arranged opposite to the laser transmitter 100. The lens module 200 is arranged between the laser transmitter 100 and the laser receiver 300, and is used for receiving the light beam emitted by the laser transmitter 100 and condensing the light beam towards the laser receiver 300. The incident light surface of the lens module 200 is arranged to be inclined to the emitting light surface of the laser transmitter 100, so that the laser reflected by the incident light surface of the lens module 200 deviates from the laser transmitter 100.

[0030] In the technical scheme, the laser transmitter 100 and the laser receiver 300 are arranged on the opposite sides of the inner wall of the air chamber 10, the lens module 200 is arranged between the laser transmitter 100 and the laser receiver 300, the lens module 200 is arranged close to the laser transmitter 100, the laser transmitter 100 emits a laser beam towards the inside of the air chamber 10, the incident light surface of the lens module 200 is arranged close to the laser transmitter 100 and receives all the light beams emitted by the laser transmitter 100, and the lens module 200 condenses the light beams and emits the light beams towards the laser receiver 300, the gas concentration is calculated by analyzing the light intensity received by the laser receiver 300 and the laser intensity emitted by the laser transmitter 100 according to the Beer-Lambert law, the incident light surface of the lens module 200 is arranged to be inclined to the emitting light surface of the laser transmitter 100, so that the laser reflected by the incident light surface of the lens module 200 deviates from the laser transmitter 100 when the laser transmitter 100 emits the laser towards the lens module 200, the laser is prevented from being reflected back to the laser transmitter 100, the laser transmitter 100 is prevented from being burned, the service life of the device is improved, the problems such as high-order mode of the laser emitted by the laser transmitter 100 are avoided, and the accuracy of the laser detection result is improved.

[0031] The scheme of the present application is not limited to detecting the gas concentration, but also can be used for detecting the micro-particle concentration in the gas, when the micro-particles are scattered in the air chamber 10, the laser transmitter 100 emits towards the air chamber 10, the light beam hits the micro-particles, and scattering is generated, the laser receiver 300 detects the intensity of the scattered light, and the particle concentration is judged, and it should be noted that, if the micro-particle concentration is detected, the laser receiver 300 is arranged on the upper wall or the lower wall in the air chamber 10, instead of being arranged opposite to the laser transmitter 100, and detailed description is not given here.

[0032] In the embodiment, the lens module 200 is arranged in the air cavity 101 and is adjacent to the light emitting surface of the laser emitter 100, receives the laser beam emitted by the laser emitter 100, and is used to convert the laser beam into a convergent processing beam. The optical axis direction of the convergent light beam can be horizontal, vertical, or inclined, which is not limited here, as long as the emitted direction can be received by the laser receiver 300. The lens module 200 can be selected as an aspheric lens. In particular, when the lens module 200 and the laser emitter 100 are arranged in relative inclination in the embodiment, the lens module 200 can be selected as a free-form surface. Through reasonable design of the free-form surface, the focused processing light beam can be better received by the laser receiver 300.

[0033] Specifically, the air chamber 10 is internally formed with an air cavity 101. The air chamber 10 can be rectangular, cylindrical or spherical, which is not limited here. The air cavity 101 can be closed or semi-closed. If it is semi-closed, an air inlet and an air outlet are arranged on one side of the air chamber 10, so that dynamic updating or continuous sampling of the gas can be achieved. The gas in the air cavity 101 can be one or more of methane, ethane, propane, acetylene or carbon monoxide, which is not limited here. Different gases absorb different wavelengths of laser. For example, methane mainly absorbs laser with a wavelength of about 1650 nm, preferably 1653 nm. If methane is detected, the laser emitter 100 emits laser with a wavelength of 1653 nm. Similarly, ethane mainly absorbs laser with a wavelength of 1682-1684 nm, preferably 1683 nm. When detecting ethane concentration, the laser emitter 100 emits laser with a wavelength of 1683 nm. Propane mainly absorbs laser with a wavelength of 1500-1700 nm, preferably 1690 nm. Carbon monoxide mainly absorbs laser with a wavelength of 1567 nm, 2.3 μm and 4.6 μm, which will not be described in detail here.

[0034] The laser transmitter 100 can adopt any one of DFB (tunable semiconductor laser), ICL (interband cascade laser), FP-LD or QCL (quantum cascade laser), which is not limited herein, and is arranged at one side of the gas cavity 101 and emits laser of a specific wavelength and a certain divergence angle towards the inside of the gas cavity 101, the divergence angle is not limited herein and is generally 5°-15°, the DFB laser is generally used for detection of methane, ethane and carbon monoxide, the ICL laser has a working wavelength band of 3-6 μm and is suitable for detection of propane or acetylene and part of hydrocarbons, the FP-LD laser can be used for preliminary screening with low precision or wavelength selection in cooperation with a filter or a grating, and the QCL laser works at 4-12 μm and has high absorption intensity and detection sensitivity. In an embodiment, different laser transmitters 100 can be arranged to emit at least one wavelength of light signal, and the light signals of different wavelengths are used for detection of different gas components in the gas.

[0035] The laser receiver 300 is arranged opposite to the laser transmitter 100 and can adopt a high-sensitivity photodetector such as an InGaAs PIN photodiode or an avalanche photodiode APD, which is not limited herein. Preferably, the detection light surface of the laser receiver 300 is provided with an anti-reflection coating, so as to reduce reflection of the converging light beam.

[0036] The concentration of the gas is calculated according to the laser intensity emitted by the laser transmitter 100 and the laser intensity received by the laser receiver 300, which can be calculated manually or by using a data processing module 20, the data processing module 20 is in communication connection with the laser transmitter 100 and the laser receiver 300 respectively, so as to receive data of the laser transmitter 100 and the laser receiver 300, and calculate according to the Beer-Lambert law, specifically .

[0037] wherein I0: intensity of incident laser; I: intensity of projected laser, i.e. intensity received by the laser receiver 300; α(ν): absorption coefficient of the gas at laser frequency ν (or wavelength λ) (unit: cm - · ppm - or cm² / molecule); c: concentration of the gas (unit: ppm, %vol or molecule / cm³); L: effective optical path length (path length of the laser passing through the gas cavity 101, unit: cm or m) i.e. according to I0and I, and known α(ν) and L, the concentration c of the gas is obtained .

[0038] In an embodiment, the lens module 200 can only include one focusing lens, the incident light surface of the focusing lens is close to the laser emitter 100 and receives all the light beams emitted by the laser emitter 100, and the laser light beams are lighted to be emitted towards the laser receiver 300. When the lens module 200 adopts the focusing lens, the lens module 200 includes an integrally formed optical group and a connecting group, the connecting group is used to fix the optical group in the air chamber 10, the optical group is opposite to the laser emitter 100 and is used to receive the light emitted by the laser emitter 100, it is to be noted that the cross-sectional size of the optical group is greater than the divergence angle of the laser emitter 100, so as to receive all the light emitted by the laser emitter 100 and avoid light loss, and the connecting group is made of high-strength and corrosion-resistant material, so as to ensure that the optical group can be stably fixed in the complex environment of the air chamber 10 and ensure the normal operation of the optical detection assembly.

[0039] As shown in Figure 1 , the focusing lens is rotated so that the incident light surface of the optical group of the focusing lens is inclined to the laser emitter 100, and as shown in Figure 2 , the laser emitter 100 is inclined so that it is inclined to the incident light surface of the optical group of the focusing lens, and the inclination mode of the focusing lens is not limited.

[0040] It is to be noted that when the lens module 200 adopts the focusing lens, the focusing lens receives the light beams emitted by the laser emitter 100 and reflects towards the laser receiver 300, and the emitted light is the light after light collection, in the path of the emitted light, there is a position where the light beam is focused into a light spot, and the distance between the laser receiver 300 and the lens module 200 is greater than the distance between the reflecting light surface of the focusing lens and the light spot, so as to avoid that the reflected light burns the laser receiver 300.

[0041] Please refer to Figure 3 , in the embodiment of the present application, the lens module 200 includes: The first lens 210 is arranged close to the laser emitter 100, and the incident light surface of the first lens 210 is inclined to the emitting light surface of the laser emitter 100; The second lens 220 is arranged between the first lens 210 and the laser receiver 300 and close to the laser receiver 300.

[0042] Specifically, the first lens 210 is configured as a collimating lens, the collimating lens receives the divergent laser beams emitted by the laser emitter 100 and is used to convert the divergent laser beams into collimated beams, the collimating lens can focus the divergent light beams with a large divergence angle emitted by the laser emitter 100 into parallel light beams with a small divergence angle, it is to be noted that as shown in Figure 3 andFigure 8 As shown, the first lens 210 has an integral optical part 212 and a connecting part 211 for fixing the optical part 212 in the air chamber 10, the optical part 212 is used for processing light, i.e. receiving the light emitted by the laser emitter 100 and emitting the light to the laser receiver 300 after refraction, the optical part 212 has an incident light surface facing the laser emitter 100 and a reflected light surface facing the laser receiver 300, the incident light surface of the optical part 212 of the first lens 210 and the emitting surface of the laser emitter 100 are arranged to be inclined to each other, so that when the first lens 210 reflects the light beam, the reflected light beam can deviate from the laser emitter 100, thereby avoiding burning the laser emitter 100 and affecting the detection accuracy. The second lens 220 is configured as a focusing lens for converging the collimated parallel light beam to the detection light surface of the laser receiver 300, the focusing lens can be selected as a plano-convex lens or a double-convex lens, the focal length and the light receiving angle need to be selected according to the diameter of the light beam to ensure that the parallel light beam can be effectively converged to the laser receiver 300.

[0043] In an embodiment, the reflected light surface of the second lens 220 and the detection light surface of the laser receiver 300 are arranged to be inclined to each other, as shown in Figure 4 When the reflected light surface of the second lens 220 is inclined to the detection light surface of the laser receiver 300, the laser reflected by the detection light surface of the laser receiver 300 will not return to the laser emitter 100 along the opposite path of the incident laser, which can further avoid affecting the detection result and improve the accuracy of the detection result and the service life of the equipment.

[0044] It should be noted that the second lens 220 is the same as the first lens 210, and also includes an optical part and a connecting part, the optical part is used for receiving the light emitted by the optical part 212 of the first lens 210 and emitting the light to the laser receiver 300 after refraction, and the connecting part is used for mounting the optical part on the inner wall of the air chamber 10, since the first lens 210 is closer to the laser emitter 100, the light reflected by the second lens 220 will not directly affect the laser emitter 100, therefore the structure of the second lens 220 will not be described in detail, and the second lens 220 is only represented by the optical part.

[0045] In the embodiment of the present application, the emitting surface of the laser emitter 100 is arranged to be non-perpendicular to the optical axis direction of the light beam after being condensed by the lens module 200, if the light beam after being focused by the first lens 210 is emitted along the horizontal direction of the optical axis direction, the emitting surface of the laser emitter 100 is inclined, which can be arranged as shown in Figure 5 the mounting base surface of the laser emitter 100 is inclined to the optical axis direction, or the mounting base surface is perpendicular to the optical axis direction and the laser emitter 100 is inclined to be mounted, which is not limited herein.

[0046] In one embodiment, such as Figure 5 As shown, the output light surface of the laser emitter 100 is tilted, and at least one of the incident light surface and the output light surface of the first lens 210 is a freeform surface. This ensures that the laser light reflected from the incident light surface and the output light surface of the first lens 210 will not be reflected back to the laser emitter 100. By adjusting the curvature of the output light surface of the first lens 210, the output laser light can not only be completely received by the laser receiver 300, but its optical axis direction can also be horizontal. Specifically, simulation and debugging can be performed using simulation software such as ZEMAX and LightTools to obtain suitable curvatures for the incident light surface and the output light surface of the first lens 210.

[0047] In one embodiment, the gas chamber 10 includes a first substrate 11, the first substrate 11 having a first mounting surface facing the laser emitter 100, the first mounting surface being inclined, and the light emitting surface of the laser emitter 100 being parallel to the first mounting surface, such that the light emitting surface of the laser emitter 100 is not perpendicular to the optical axis direction of the light beam after being focused and collimated by the first lens 210.

[0048] Specifically, the first substrate 11 serves as the mounting base surface for the laser emitter 100. The first substrate 11 has a first mounting surface facing into the gas cavity 101. The first mounting surface is inclined in the vertical direction, thereby causing the laser emitter 100 on the first mounting surface to be inclined, such as... Figure 5 As shown, the distance between the upper end of the first mounting surface and the laser receiver 300 is greater than the distance between the lower end of the first mounting surface and the laser receiver 300. That is, the entire first mounting surface is tilted upward, which means that the light emitting surface of the first mounting surface is tilted upward. The first lens 210 can be a plano-convex mirror or a biconvex mirror, preferably a biconvex mirror. The incident light surface and the reflected light surface of the first lens 210 are preferably free-form surfaces, which can prevent the incident light surface of the first lens 210 from reflecting the laser to the laser emitter 100 and affecting the emission of the laser emitter 100.

[0049] In another embodiment, the tilt direction of the first mounting surface can also be opposite, such as the distance between the upper end of the first mounting surface and the laser receiver 300 being less than the distance between the lower end of the first mounting surface and the laser receiver 300. Correspondingly, the first lens 210 is preferably a biconvex lens with a free-form surface.

[0050] In some embodiments, the detection surface of the laser receiver 300 and the optical axis of the beam collimated by the first lens 210 are not perpendicular, such as... Figure 6As shown, if the optical axis direction of the collimated parallel light beam is horizontal, the detection light plane of the laser receiver 300 is inclined, which can be achieved by inclining the mounting base plane of the laser receiver 300 relative to the optical axis direction, or by inclining the laser receiver 300 itself relative to the horizontal direction, and the inclination is not limited herein.

[0051] In an embodiment, as shown in Figure 6 the detection light plane of the laser receiver 300 is inclined, at least one of the incident light plane and the emitting light plane of the second lens 220 is a free-form surface (not shown in the figure), and the curvature of the free-form surface can be simulated and debugged by computer ZEMAX or LightTools, so that the second lens 220 can completely receive the parallel light beam and emit the focused light beam to the laser receiver 300, which can prevent the laser from being reflected to the laser emitter 100 and ensure that the focused laser can be received by the laser receiver 300.

[0052] In an embodiment, the air chamber 10 includes a second substrate 12 having a second mounting surface facing the laser receiver 300, the second mounting surface is inclinedly arranged, and the detection light plane of the laser receiver 300 is parallel to the second mounting surface, so that the detection light plane of the laser receiver 300 and the optical axis direction of the light beam collimated by the first lens 210 are non-perpendicularly arranged.

[0053] Specifically, the second substrate 12 serves as the mounting base plane of the laser receiver 300 and has a second mounting surface facing the air cavity 101, and the second substrate 12 is arranged opposite to the first substrate 11, as shown in Figure 6 the second mounting surface is inclinedly arranged, which can be achieved by setting the distance between the upper end of the second mounting surface and the laser emitter 100 to be greater than the distance between the lower end of the second mounting surface and the laser emitter 100, as long as the receiving point of the laser receiver 300 is located at the focal center of the second lens 220, the second lens 220 can be a double-convex lens or a plano-convex lens, and preferably a double-convex lens, the incident light plane and the emitting light plane of the second lens 220 are set to be free-form surfaces to prevent the laser from being reflected to the laser emitter 100, and the curvature can also be adjusted so that the laser can be focused to the laser receiver 300 and thus be received by the laser receiver 300.

[0054] In an embodiment, as shown in Figure 3 and Figure 5 the detection light plane of the laser receiver 300 is perpendicular to the optical axis direction of the light beam collimated by the condenser, at this time, the detection light plane of the laser receiver 300 is not inclined relative to the emitting light plane of the second lens 220, and preferably, the incident light plane and the emitting light plane of the second lens 220 are set to be free-form surfaces to avoid the laser being reflected back to the laser emitter 100.

[0055] In an embodiment, the light receiving surface of the laser receiver 300 is perpendicular to the optical axis direction of the light beam after converging and collimating, and one end of the second lens 220 is relatively inclined. The upper end of the second lens 220 can be inclined towards the direction away from the laser receiver 300, or the lower end of the laser receiver 300 can be inclined towards the direction away from the laser receiver 300 as shown in Figure 4 . The reflected laser of the laser receiver 300 will not be reflected to the laser emitter 100.

[0056] In the above embodiment, the second substrate 12 can be perpendicular to the optical axis direction, the light receiving surface of the laser receiver 300 can be parallel to the second mounting surface, and the light receiving surface of the laser receiver 300 can be perpendicular to the optical axis direction.

[0057] In the embodiment of the present application, the light emitting surface of the laser emitter 100 is perpendicular to the optical axis direction of the light beam after converging and collimating by the first lens 210, one end of the optical part 212 is inclined, and the curvature of the light reflecting surface of the optical part 212 away from the one end of the laser emitter 100 is greater than the curvature close to the one end of the laser emitter 100. Such design will be conducive to the first lens 210 to tilt the light beam to the side with greater curvature, and the light beam will be more focused and easier to be received by the laser receiver 300. As shown in Figure 1 , Figure 3 , Figure 4 and Figure 6 , the first substrate 11 is perpendicular to the optical axis direction, and the laser emitter 100 on the first mounting surface is also perpendicular to the optical axis direction. One end of the optical part 212 is inclined, so that the light incident surface of the optical part 212 is inclined relative to the laser emitter 100. It can be understood that the normal line of any point on the light incident surface of the optical part 212 is not perpendicular to the light emitting surface of the laser emitter 100. When the laser emitter 100 emits laser towards the first lens 210, all the reflected light of the first lens 210 deviates from the laser emitter 100.

[0058] In an embodiment, as shown in Figure 1 , Figure 3 , Figure 4 and Figure 6 , the lower end of the optical part 212 is inclined towards the direction away from the laser emitter 100, and the reflected laser of the light incident surface of the first lens 210 is reflected towards the lower left. By adjusting the inclination angle of the first lens 210, when the uppermost end of the light beam emitted by the laser emitter 100 is reflected by the first lens 210, the reflected laser is directed to the lower end of the laser emitter 100. Thus, all the reflected laser on the light incident surface of the first lens 210 can be reflected below the laser emitter 100.

[0059] In an embodiment, the upper end of the optical part 212 is tilted towards the direction away from the laser emitter 100 (not shown in the figure), that is, the lower end of the optical part 212 is closer to the laser emitter 100 than the upper end, and the angle needs to be adjusted so that the laser emitted by the laser emitter 100 at the lowermost end is reflected to the upper end of the laser emitter 100 when it is incident on the light-incident surface of the first lens 210, that is, all the laser reflected by the light-incident surface of the first lens 210 deviates from the laser emitter 100.

[0060] Correspondingly, if the reflective surface of the first lens 210 is a symmetrical convex surface, it will cause the parallel light beam to tilt, which is not conducive to the reception of the second lens 220, and therefore the curvature of the light-incident surface of the optical part 212 is adjusted so that the parallel light beam after collimation is horizontally directed towards the second lens 220, and when the lower end of the optical part 212 is tilted towards the direction away from the laser emitter 100, the curvature of the lower end of the reflective surface of the optical part 212 is set to be greater than the curvature of the upper end, and in another embodiment, when the upper end of the optical part 212 is tilted towards the direction away from the laser emitter 100, the curvature of the upper end of the reflective surface of the optical part 212 is set to be greater than the curvature of the lower end. This design will be conducive to the first lens 210 tilting the light beam to the side with greater curvature, and the light beam will be more focused and easier to be received by the laser receiver 300. The specific curvature value is related to the tilt angle of the first lens 210 and can be obtained by simulation using ZEMAX or LightTools software, which will not be described in detail here. Figure 3 、 Figure 4 and Figure 6 , the curvature of the lower end of the reflective surface of the optical part 212 is set to be greater than the curvature of the upper end, and in another embodiment, when the upper end of the optical part 212 is tilted towards the direction away from the laser emitter 100, the curvature of the upper end of the reflective surface of the optical part 212 is set to be greater than the curvature of the lower end. This design will be conducive to the first lens 210 tilting the light beam to the side with greater curvature, and the light beam will be more focused and easier to be received by the laser receiver 300. The specific curvature value is related to the tilt angle of the first lens 210 and can be obtained by simulation using ZEMAX or LightTools software, which will not be described in detail here.

[0061] As shown in Figure 7 , the divergence angle of the laser emitted by the laser emitter 100 is 2α degrees, that is, the half angle is α degrees, and one end of the optical part 212 is tilted so that the light-incident surface of the optical part 212 is tilted relative to the laser emitter 100 to form a tilt angle of β degrees, and at least β>α is required to make all the light reflected by the first lens 210 deviate from the laser emitter 100, that is, as shown in Figure 7 , the uppermost light ray is also reflected to the lower end of the laser emitter 100.

[0062] In the embodiment of the present application, the receiving full angle of the second lens 220 is greater than or equal to the divergence full angle of the first lens 210, that is, the receiving full angle of the second lens 220 is greater than the distance between the two ends of the collimated light beam, which can ensure that the collimated light beam transmitted through the air cavity 101 can be completely captured and focused to the detection light surface of the laser receiver 300 by the second lens 220, avoiding the loss of light energy and causing the concentration measurement to be low or unstable, and the receiving full angle of the second lens 220 is determined by its focal length f and the clear aperture D, and the receiving full angle is twice the receiving half angle, and the receiving half angle And the focal length of the second lens 220 is simulated and optimized by ZEMAX or LightTools to make the focal point fall in the center of the photosensitive area of the laser receiver 300, thereby improving the accuracy of concentration calculation.

[0063] In the embodiment of the present application, the inner wall of the gas chamber 10 structure is provided with a light-absorbing coating, which can absorb the laser reflected on the inner wall, prevent the reflected laser from entering the laser emitter 100 or the laser receiver 300 after multiple reflections in the inner wall of the gas chamber 10, and affect the normal detection, thereby improving the accuracy of gas concentration detection.

[0064] In an embodiment, the inner wall of the gas chamber 10 structure is black resin or black film layer, which has good light absorption performance and low cost.

[0065] In other embodiments, the inner wall of the gas chamber 10 can also be provided with a carbon nanotube coating, which has super-black characteristics and a laser absorption rate of more than 99% in a wide waveband, which is not limited here.

[0066] It should be noted that when selecting the light-absorbing coating, the absorption efficiency of the coating material at the target laser wavelength and the chemical stability in the gas to be measured should be considered, so as to reduce the influence on the gas concentration detection.

[0067] In the embodiment of the present application, the inner wall of the gas chamber 10 structure is provided with a sawtooth structure, which can increase the surface area of the inner wall of the gas chamber 10, improve the absorption rate of the laser reflected on the inner wall, avoid affecting the normal detection, reduce the influence on the gas concentration detection, and make the gas concentration calculation more accurate.

[0068] In an embodiment, the sawtooth structure can be configured as a concave-convex structure, and can also be a continuously arranged arc-shaped groove, which is not limited here, as long as it can increase the surface area of the inner wall of the gas chamber 10.

[0069] The above description is only an exemplary embodiment of the present application, and does not limit the protection scope of the present application. Any equivalent structural transformation made by referring to the content of the present application specification and drawings, or direct / indirect application in other related technical fields is included in the protection scope of the present application.

Claims

1. An optical detection component applied to a gas chamber structure, the gas chamber structure having a gas cavity filled with gas, characterized in that, The optical detection component includes: A laser emitter is disposed in the gas chamber structure, and the laser emitter is used to emit a laser beam toward the gas chamber; A laser receiver is disposed in the gas chamber structure and is positioned opposite to the laser emitter; A lens module is disposed between the laser emitter and the laser receiver. The lens module is used to receive the light beam emitted by the laser emitter and focus the light towards the laser receiver. The incident light surface of the lens module and the emitting light surface of the laser emitter are inclined to each other, so that the laser reflected from the incident light surface of the lens module deviates from the laser emitter.

2. The optical detection component as described in claim 1, characterized in that, The lens module includes: A first lens is disposed close to the laser emitter, and the incident light surface of the first lens and the emitting light surface of the laser emitter are inclined relative to each other. The second lens is disposed between the first lens and the laser receiver, and is positioned close to the laser receiver.

3. The optical detection component as described in claim 2, characterized in that, The laser emitter's output surface is not perpendicular to the optical axis of the beam focused by the lens module. And / or, the detection surface of the laser receiver and the optical axis of the beam focused by the lens module are not perpendicular.

4. The optical detection component as described in claim 3, characterized in that, When the output light surface of the laser emitter is not perpendicular to the optical axis of the beam focused by the lens module, at least one of the incident light surface and the output light surface of the first lens is a freeform surface. And / or, when the detection light surface of the laser receiver and the optical axis of the beam focused by the lens module are not perpendicular, at least one of the incident light surface and the emitting light surface of the second lens is a freeform surface.

5. The optical detection component as described in claim 4, characterized in that, The gas chamber includes a first substrate, the first substrate having a first mounting surface facing the laser emitter, the first mounting surface being inclined, and the light emission surface of the laser emitter being parallel to the first mounting surface, such that the light emission surface of the laser emitter is not perpendicular to the optical axis direction of the light beam collimated by the first lens; And / or, the gas chamber includes a second substrate having a second mounting surface facing the laser receiver, the second mounting surface being inclined, and the detection surface of the laser receiver being parallel to the second mounting surface, such that the detection surface of the laser receiver and the optical axis direction of the beam collimated by the first lens are not perpendicular.

6. The optical detection component as described in claim 2, characterized in that, The first lens includes an optical section for light processing. The light-emitting surface of the laser emitter is perpendicular to the optical axis of the light beam after being focused by the lens module. One end of the optical section is inclined, and the curvature of the end of the optical section away from the laser emitter is greater than the curvature of the end closer to the laser emitter.

7. The optical detection component as described in claim 6, characterized in that, The divergence angle of the laser emitted by the laser emitter is set to 2α degrees. One end of the optical part is tilted so that the incident light surface of the optical part is tilted relative to the laser emitter, forming a tilt angle of β degrees. The relationship between this tilt angle and the divergence angle of the laser emitted by the laser emitter is β > α.

8. The optical detection component according to any one of claims 2-7, characterized in that, The receiving angle of the second lens is greater than or equal to the diverging angle of the first lens.

9. The optical detection component as described in claim 8, characterized in that, The inner wall of the air chamber structure is provided with a light-absorbing coating; And / or, the inner wall of the air chamber structure is made of black resin or a black film layer.

10. The optical detection component as claimed in claim 9, characterized in that, The inner wall of the air chamber structure is provided with a serrated structure.

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