Optical cavity for laser telemetering calibration

Abstract

The invention provides an optical cavity for laser telemetering calibration, and belongs to the technical field of laser telemetering calibration, the optical cavity for laser telemetering calibration comprises a measuring cylinder, a light inlet cylinder, a light trap assembly and an air exhaust assembly, the top side wall position and the bottom side wall position of the measuring cylinder are connected with the light inlet cylinder and the light trap assembly in a penetrating mode respectively, and the light inlet cylinder is used for reflecting light emitted by the laser remote measuring instrument into the measuring cylinder. The light trap assembly is used for capturing the light reflected by the light inlet cylinder so as to reduce the influence of the light entering the measuring cylinder on a calibration result; the bottom of the measuring cylinder is connected with the air exhaust assembly, and the air exhaust assembly is used for exhausting air in the measuring cylinder and measuring the volume of the exhausted air; the invention provides an optical cavity for laser telemetering calibration, which can solve the problem of low calibration accuracy caused by the fact that the existing laser telemetering calibration is easily influenced by the environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser telemetry calibration, and in particular relates to an optical cavity for laser telemetry calibration. Background Art

[0002] Laser ranging technology uses the time or optical path taken by a laser beam to reflect back to calculate distance. Specifically, a laser telemetry system transmits a laser beam and measures the time or frequency changes in the reflected light signal to calculate the distance between the object and the measuring device. The relatively monochromatic, highly directional, and stable nature of lasers make this measurement method far superior to traditional physical measurement methods in terms of accuracy and sensitivity. During the propagation of a laser beam, it is affected by various factors, such as air, ambient temperature, humidity, and air pressure, which can cause measurement errors. To improve the measurement accuracy of laser telemetry systems, various methods must be used to calibrate and compensate for the propagation characteristics of the laser beam. For example, error correction can be performed by measuring laser reflectivity, beam scattering, and refraction. Laser telemetry technology requires high precision in various applications, especially in industries with high precision requirements, such as aerospace, autonomous driving, surveying and mapping, and physical experiments. To ensure the accuracy of laser measurement systems, calibration technology has become an indispensable component of laser telemetry applications. Calibration technology can eliminate the influence of environmental changes, beam unevenness, and equipment errors on measurement results.

[0003] Existing laser telemetry calibration performs feedback control and correction by comparing standard measurements with the actual emitted light beam, which is easily affected by the environment, resulting in low calibration accuracy. Summary of the Invention

[0004] In view of this, the present invention provides an optical cavity for laser telemetry calibration, which can solve the problem that the existing laser telemetry calibration is easily affected by the environment, resulting in low calibration accuracy.

[0005] The present invention is achieved in that: The present invention provides an optical cavity for laser telemetry calibration, which includes a measuring cylinder, a light inlet cylinder, a light trap assembly, and an exhaust assembly. The measuring cylinder is an elongated cylindrical structure, and the top side wall and the bottom side wall of the measuring cylinder are respectively connected to the light inlet cylinder and the light trap assembly. The light inlet cylinder is used to reflect light emitted by a laser telemeter into the interior of the measuring cylinder, and the light trap assembly is used to capture the light reflected by the light inlet cylinder to reduce the influence of the light entering the interior of the measuring cylinder on the calibration result; the bottom of the measuring cylinder is connected to the exhaust assembly, and the exhaust assembly is used to extract gas from the interior of the measuring cylinder and measure the volume of the extracted gas; the bottom of the light trap assembly is connected to the exhaust assembly, and the top of the measuring cylinder is connected to a gas compensation assembly, which is used to reduce the influence of the environment on the calibration result at a position where the measuring cylinder is located between the light inlet cylinder and the light trap assembly; the top of the measuring cylinder is connected to an aerosol introduction tube, which is used to introduce aerosol into the interior of the measuring cylinder.

[0006] The optical cavity for laser telemetry calibration provided by the present invention has the following technical effects: The measuring cylinder provides a sealed, interference-free environment for laser measurement of aerosols of known concentrations, minimizing interference from factors such as gravity and reflected light, thereby ensuring measurement accuracy. The light inlet cylinder guides light emitted by the laser telemeter into the measuring cylinder. After entering the measuring cylinder from the light inlet cylinder, the laser beam follows a specific path and angle, ensuring that it passes through the measuring cylinder and is ultimately absorbed by a light trap assembly. The light trap assembly captures the light entering the light inlet cylinder, minimizing interference from ambient light on the measurement results. The air extraction assembly extracts gas from the measuring cylinder and measures the volume of the extracted gas, allowing the powder concentration to be calculated based on the weight-to-volume ratio, providing a standard for calibration results. Connecting an air inlet assembly to the bottom of the light trap assembly ensures that airflow flows toward the center of the measuring cylinder at the junction between the measuring cylinder and the light trap assembly, preventing aerosol from entering the light trap assembly. By connecting a gas compensation assembly to the top of the measuring cylinder, the air pressure inside the measuring cylinder, the light inlet cylinder, and the light trap assembly can always be kept stable; through the aerosol inlet tube connected to the top of the measuring cylinder, an aerosol of known mass is transported into the interior of the measuring cylinder to calibrate the laser telemetry instrument.

[0007] On the basis of the above technical solution, the optical cavity for laser telemetry calibration of the present invention can also be improved as follows: Among them, the connection angles of the light inlet tube, the light trap assembly and the measuring tube are matched so that the axes of the light inlet tube and the light trap assembly are located on the same horizontal line, which is used to ensure that the light reflected by the light inlet tube into the inside of the measuring tube is absorbed by the light trap assembly after passing through the measuring tube, so as to reduce the influence of ambient light on the calibration results.

[0008] The beneficial effect of adopting the above-mentioned improvement scheme is: by matching the angles of the light inlet tube and the light trap assembly, it is ensured that the light reflected by the light inlet tube enters the measuring tube, passes through the measuring tube and is absorbed by the light trap, thereby reducing the influence of ambient light.

[0009] Furthermore, a reflector is provided at the top of the light inlet tube, and the reflector is fixed at a specified angle on the top of the light inlet tube by a bracket. The bracket is fixed to the top of the light inlet tube by double bolts, which is used to ensure that the reflection angle of the laser emitted from the specified position after being reflected by the reflector coincides with the central axis of the reflector.

[0010] The beneficial effect of adopting the above-mentioned improved solution is that, by matching the reflector and angle at the top of the measuring tube, the laser reflection angle can be made consistent with the central axis of the reflector, further ensuring the accurate transmission of the light beam.

[0011] Furthermore, the position of the measuring cylinder between the light inlet cylinder and the light trap assembly is a measuring part, and the length of the measuring part is greater than 1.5m, which is used to eliminate the influence of gravity on the measurement result.

[0012] The beneficial effect of adopting the above-mentioned improvement scheme is that by making the length of the measuring part greater than 1.5 meters, the influence of gravity on the measurement result is eliminated, thereby further ensuring the accuracy of the calibration result.

[0013] Furthermore, the light trap assembly also includes a conical light trap, a base and an air inlet groove. The base is arranged at the bottom of the light trap assembly, and the conical light trap is connected to the top of the base. The conical light trap is used to absorb light inside the light trap assembly; four air inlet grooves are provided at the position where the conical light trap is connected to the base. The air inlet grooves are connected to the air inlet assembly connected to the bottom of the light trap assembly and are used to transport gas to the interior of the light trap assembly.

[0014] Furthermore, the exhaust assembly includes a conical guide hole fixed at the bottom of the measuring cylinder, which is used to concentrate the gas to facilitate the determination of the gas volume; a powder collection filter is provided at the bottom of the conical guide hole, which is used to collect aerosols in the extracted gas. The aerosols are gathered into powder through extraction, and the powder is weighed, and the concentration of the powder is determined by the ratio of weight to volume.

[0015] Furthermore, a spiral mixer is connected to the inner wall of the top of the measuring cylinder, and a rotating motor is connected to the top of the measuring cylinder. The spiral mixer is made of flexible material and its size is smaller than the inner radius of the measuring cylinder. It is used to disturb the airflow through rotation to make the aerosol entering the measuring part more uniform, thereby ensuring the accuracy of the calibration structure.

[0016] Furthermore, a plane mirror is fixed on the top of the light intake tube, which is used to form a sealed environment inside the measuring tube, the light intake tube and the light trap assembly.

[0017] The beneficial effects of adopting the above-mentioned improvement scheme are: in order to prevent interference from external light, a plane mirror is fixed on the top of the light inlet tube to form a sealed environment, ensuring that there are no unnecessary external influences during the measurement process, and ensuring the accurate transmission of the light beam and the final calibration effect.

[0018] Furthermore, the gas compensation assembly connected to the top of the measuring cylinder includes an air duct connected to the inside of the measuring cylinder and an air pump that transports dry and clean gas to the inside of the air duct; the air intake assembly connected to the bottom of the light trap assembly includes an air intake pipe connected to the bottom position of the light trap assembly and an air pump that transports dry and clean gas to the inside of the air intake pipe.

[0019] Furthermore, the volume of gas extracted by the gas extraction component is the same as the volume of gas delivered to the interior of the measuring cylinder by the gas compensation component connected to the top of the measuring cylinder and the air intake component connected to the bottom of the light trap component.

[0020] Compared with the prior art, the optical cavity for laser telemetry calibration provided by the present invention has the following beneficial effects: The measuring tube, a long cylindrical structure, is the core of the optical cavity, providing a sealed, interference-free environment. This design effectively minimizes interference from factors such as gravity, airflow, and ambient light on laser telemetry measurements. During laser telemetry calibration, the gas concentration inside the measuring tube must be precisely controlled. Therefore, ensuring the cavity's tightness ensures high measurement accuracy.

[0021] The light inlet tube serves as the entrance for the laser beam into the measuring tube, guiding the light emitted by the laser telemeter into the measuring tube. This design ensures precise beam transmission, avoiding errors caused by light scattering or refraction. Furthermore, the light inlet tube is equipped with a reflector that adjusts the reflection angle to ensure that the laser enters the measuring tube precisely and reaches the light trap assembly through a specific path and angle.

[0022] The light trap assembly is a key component in the optical cavity. Its primary function is to capture light entering the measuring tube and reduce ambient light interference with the measurement results. The light trap assembly features a conical light trap and air inlet slots at the bottom, effectively absorbing the laser beam and preventing the influence of external light, thereby ensuring measurement accuracy. Furthermore, the gas flow design within the light trap prevents aerosols from entering the light trap and affecting the calibration process.

[0023] The extraction assembly is designed to extract gas from the measuring cylinder and determine its volume using a volumetric measurement system. This function provides standard gas volume data, allowing the powder concentration to be calculated using the weight-to-volume ratio, providing an accurate calibration standard for the laser telemeter. The use of a tapered guide hole makes the extraction process more efficient, and the filter at the bottom effectively collects powder from the extracted gas to prevent contamination.

[0024] The gas compensation assembly ensures a stable pressure inside the measuring cylinder, preventing external pressure fluctuations from interfering with calibration results. By connecting a gas line and supplying dry, clean gas to it, this assembly maintains a stable measurement environment and improves the reliability of calibration results.

[0025] The spiral mixer's rotational disturbance of the airflow evenly distributes the aerosol, preventing uneven aerosol deposition that can affect measurement accuracy. The spiral mixer's flexible material ensures no friction with the inner wall of the measuring tube, preventing the introduction of additional interference factors.

[0026] To prevent interference from external light, the plane mirror and connecting components at the top of the light tube form a closed optical path. This sealed design ensures that external light cannot enter the system, thereby ensuring the precise transmission of the light beam and the effectiveness of the measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of an optical cavity for laser telemetry calibration; Figure 2 This is a schematic diagram of the top structure of an optical cavity used for laser telemetry calibration; Figure 3 Schematic diagram of the structure of the light trap assembly; Figure 4 It is a structural diagram of the air extraction component; Figure 5 Schematic diagram of the planar structure of the exhaust component; In the accompanying drawings, the components represented by the reference numerals are as follows: 10. Measuring tube; 11. Measuring part; 20. Light inlet tube; 21. Reflector; 30. Light trap assembly; 31. Conical light trap; 32. Base; 33. Air inlet slot; 40. Air extraction assembly. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0029] like Figure 1-5 As shown, an embodiment of an optical cavity for laser telemetry calibration provided by the present invention is provided. In this embodiment, it includes a measuring tube 10, a light inlet tube 20, a light trap assembly 30 and an air extraction assembly 40. The measuring tube 10 is a long cylindrical structure, and the top side wall and the bottom side wall thereof are respectively connected to the light inlet tube 20 and the light trap assembly 30. The light inlet tube 20 is used to reflect the light emitted by the laser telemetry instrument into the interior of the measuring tube 10, and the light trap assembly 30 is used to capture the light reflected by the light inlet tube 20 to reduce the light entering the interior of the measuring tube 10. Impact on the calibration results; the bottom of the measuring cylinder 10 is connected to an exhaust component 40, which is used to extract the gas inside the measuring cylinder 10 and measure the volume of the extracted gas; the bottom of the light trap component 30 is connected to an air intake component, and the top of the measuring cylinder 10 is connected to a gas compensation component, which is used to reduce the impact of the environment on the calibration results when the measuring cylinder 10 is located between the light intake cylinder 20 and the light trap component 30; the top of the measuring cylinder 10 is connected to an aerosol inlet tube, which is used to introduce aerosol into the interior of the measuring cylinder 10.

[0030] Among them, in the above technical solution, the connection angles of the light inlet tube 20, the light trap assembly 30 and the measuring tube 10 are matched, so that the axes of the light inlet tube 20 and the light trap assembly 30 are located on the same horizontal line, which is used to ensure that the light reflected by the light inlet tube 20 and entering the interior of the measuring tube 10 is absorbed by the light trap assembly 30 after passing through the measuring tube 10, so as to reduce the influence of ambient light on the calibration results.

[0031] Furthermore, in the above technical solution, a reflector 21 is provided at the top of the light input tube 20, and the reflector 21 is fixed at a specified angle on the top of the light input tube 20 by a bracket. The bracket and the top of the light input tube 20 are fixedly connected by double bolts to ensure that the reflection angle of the laser emitted at the specified position after being reflected by the reflector 21 coincides with the center axis of the reflector 21.

[0032] Furthermore, in the above technical solution, the position of the measuring tube 10 between the light inlet tube 20 and the light trap assembly 30 is the measuring portion 11 , and the length of the measuring portion 11 is greater than 1.5 m, which is used to eliminate the influence of gravity on the measurement results.

[0033] Furthermore, in the above technical solution, the light trap assembly 30 also includes a conical light trap 31, a base 32 and an air inlet groove 33. The base 32 is arranged at the bottom of the light trap assembly 30, and the conical light trap 31 is connected to the top of the base 32. The conical light trap 31 is used to absorb light inside the light trap assembly 30; four air inlet grooves 33 are provided at the position where the conical light trap 31 is connected to the base 32. The air inlet grooves 33 are connected to the air inlet assembly connected to the bottom of the light trap assembly 30 and are used to transport gas to the interior of the light trap assembly 30.

[0034] Furthermore, in the above technical solution, the exhaust assembly 40 includes a conical guide hole fixed at the bottom of the measuring tube 10, which is used to concentrate the gas to facilitate the determination of the gas volume; a powder collection filter is provided at the bottom of the conical guide hole, which is used to collect aerosols in the extracted gas. The aerosols are aggregated into powder during the air extraction process, and the powder is weighed to determine the concentration of the powder by the ratio of weight to volume.

[0035] Furthermore, in the above technical solution, a spiral mixer is connected to the inner wall of the top of the measuring cylinder 10, and a rotating motor is externally connected through the top of the measuring cylinder 10. The spiral mixer is made of flexible material and its size is smaller than the inner radius of the measuring cylinder 10. It is used to disturb the airflow through rotation so that the aerosol entering the measuring part 11 is more uniform, thereby ensuring the accuracy of the calibration structure.

[0036] Furthermore, in the above technical solution, a plane mirror is fixed on the top of the light inlet tube 20 to form a sealed environment inside the measuring tube 10 , the light inlet tube 20 and the light trap assembly 30 .

[0037] Furthermore, in the above technical solution, the gas compensation assembly connected to the top of the measuring tube 10 includes an air guide tube connected to the inside of the measuring tube 10 and an air pump that transports dry and clean gas to the inside of the air guide tube; the air intake assembly connected to the bottom of the light trap assembly 30 includes an air intake tube connected to the bottom position of the light trap assembly 30 and an air pump that transports dry and clean gas to the inside of the air intake tube.

[0038] Furthermore, in the above technical solution, the volume of gas extracted by the exhaust assembly 40 is the same as the volume of gas delivered to the interior of the measuring cylinder 10 by the gas compensation assembly connected to the top of the measuring cylinder 10 and the air intake assembly connected to the bottom of the light trap assembly 30 .

[0039] The measuring tube, a long cylindrical structure, provides a closed, interference-free environment for calibrating laser telemetry instruments. By preventing interference from environmental factors such as gravity and reflected light, the measuring tube helps improve measurement accuracy. During laser telemetry, the top and bottom walls of the measuring tube connect to the light inlet and light trap components, respectively, forming an optical cavity that ensures the laser beam enters and is properly absorbed through a specific path.

[0040] The light inlet tube guides the laser beam emitted by the laser telemeter into the measuring tube. The laser beam follows a specific path within the light inlet tube before entering the measuring tube. It then passes through specific angles and areas within the measuring tube before being absorbed by the light trap assembly. During this process, the laser beam's path and angle are precisely designed to ensure that the laser beam passes through the measuring tube and is accurately captured, minimizing the influence of external light.

[0041] The primary function of the light trap assembly is to capture the laser beam entering the measuring tube from the light inlet tube, preventing reflection or scattering that could interfere with the measurement. To achieve this, the light trap assembly utilizes a conical structure designed to effectively absorb light, ensuring that the laser beam no longer reflects and affects the measurement. The bottom of the light trap assembly is connected to the air inlet assembly, allowing airflow to enter, preventing aerosols from entering the light trap and ensuring system stability.

[0042] The extraction assembly helps maintain a stable gas environment within the system by extracting gas from the measuring cylinder. This assembly typically features a tapered guide hole at the bottom for centralized gas extraction, facilitating volume measurement. The volume of gas extracted can be measured, and combined with the known mass of the powder, the powder concentration can be calculated, providing a standard for calibrating the laser telemetry instrument. The extraction assembly also includes a powder collection filter to collect the powder for gravimetric analysis, further ensuring calibration accuracy.

[0043] To prevent environmental factors from influencing measurement results, the design of the gas compensation assembly and air intake assembly is crucial. The gas compensation assembly, located at the top of the measuring tube, maintains a stable pressure inside the tube by delivering clean, dry gas, preventing external gas fluctuations from interfering with the measurement process. Furthermore, the air intake assembly at the bottom of the light trap assembly ensures a stable airflow direction inside the light trap, preventing aerosols from entering the light trap and affecting measurement results.

[0044] A spiral mixer, located at the top of the measuring tube, rotates and turbulently stirs the airflow, ensuring a more uniform aerosol entering the tube. This design eliminates measurement errors that can arise from uneven aerosol accumulation, further ensuring measurement accuracy.

[0045] To further enhance the accuracy of the laser beam, a reflector is installed at the top of the light tube. The reflector's angle is precisely adjusted to ensure that the laser beam's reflection path meets the design requirements and accurately enters the measuring tube. Furthermore, a plane mirror is fixed to the top of the light tube to create a sealed environment, preventing interference from external light sources and ensuring accurate beam transmission and stable measurement results.

[0046] The optical cavity of this invention features a highly sealed design. All key components utilize precise angle adjustment and fixtures to ensure accurate laser beam path alignment. Furthermore, the replenishment and extraction of ambient gas is strictly controlled through the coordination of a gas pump and gas tube to ensure a stable internal environment during laser measurement. Gas replenishment and extraction are performed according to calibration standards for volume and mass calculations, ensuring the accuracy of the final results.

[0047] Through sealing, temperature control, airflow control and other methods, the laser telemetry instrument can avoid external interference during the calibration process, ensure measurement accuracy, optimize the transmission of the laser beam, the distribution of aerosols and the stability of the gas environment, making the laser telemetry calibration process more accurate and reliable.

[0048] Specifically, the principle of this invention is as follows: When the laser telemeter is turned on, the laser beam passes through the light inlet tube and into the measuring tube. At this point, the laser beam must pass through the light inlet tube's reflector to ensure that the beam enters the measuring tube at a precise angle. This ensures that the beam travels along a precise path and directly enters the light trap assembly. The light trap absorbs the beam and reduces interference from external light sources during the calibration process.

[0049] Start the air inlet assembly, gas compensation assembly, and air extraction assembly to ensure that the air pressure in the measuring cylinder is stable. Use the gas compensation assembly to replenish clean, dry gas into the measuring chamber to prevent changes in ambient air pressure from affecting measurement accuracy.

[0050] Activate the spiral mixer, causing it to rotate and disrupt the airflow within the measuring cylinder to ensure that the aerosol is evenly distributed within the measuring cylinder. The action of the spiral mixer helps prevent aerosol sedimentation and accumulation, thereby reducing measurement errors.

[0051] An aerosol of known weight is added to the interior of the measuring cylinder through the aerosol inlet tube to ensure that the aerosol falls evenly in the optical cavity. The volume of gas extracted by the exhaust component is determined, and the concentration of the powder is determined by the weight-to-volume ratio to calibrate the measurement results of the laser telemeter.

[0052] For aerosols of unknown weight, the powder after aerosol aggregation is collected through a powder collection filter and weighed to determine the volume of gas extracted by the extraction component. The concentration of the powder is determined by the ratio of weight to volume, and the measurement results of the laser telemeter are calibrated.

[0053] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed by the present invention, which should be covered by the scope of protection of the present invention.

Claims

1. An optical cavity for laser telemetry calibration, characterized in that: The invention comprises a measuring tube (10), a light inlet tube (20), a light trap assembly (30) and an air extraction assembly (40), wherein the measuring tube (10) is an elongated cylindrical structure, and the top side wall position and the bottom side wall position thereof are respectively connected with the light inlet tube (20) and the light trap assembly (30), the light inlet tube (20) is used to reflect the light emitted by the laser telemeter into the interior of the measuring tube (10), and the light trap assembly (30) is used to capture the light reflected by the light inlet tube (20) to reduce the influence of the light entering the interior of the measuring tube (10) on the calibration result; the measuring tube (10) is provided with a plurality of holes, wherein the holes are ... The bottom is connected to the exhaust component (40), and the exhaust component (40) is used to extract the gas inside the measuring cylinder (10) and measure the volume of the extracted gas; the bottom of the light trap component (30) is connected to the air intake component, and the top of the measuring cylinder (10) is connected to the gas compensation component, which is used to reduce the influence of the environment on the calibration result when the measuring cylinder (10) is located between the light intake cylinder (20) and the light trap component (30); the top of the measuring cylinder (10) is connected to the aerosol introduction tube, which is used to introduce aerosol into the interior of the measuring cylinder (10).

2. The optical cavity for laser telemetry calibration according to claim 1, characterized in that: The connection angles of the light inlet tube (20), the light trap assembly (30) and the measuring tube (10) are matched so that the axes of the light inlet tube (20) and the light trap assembly (30) are located on the same horizontal line, which is used to ensure that the light reflected by the light inlet tube (20) and entering the interior of the measuring tube (10) is absorbed by the light trap assembly (30) after passing through the measuring tube (10), thereby reducing the influence of ambient light on the calibration result.

3. The optical cavity for laser telemetry calibration according to claim 2, characterized in that: A reflector (21) is provided at the top of the light inlet tube (20), and the reflector (21) is fixed at a specified angle on the top of the light inlet tube (20) by a bracket. The bracket and the top of the light inlet tube (20) are fixedly connected by double bolts to ensure that the reflection angle of the laser emitted from the specified position after being reflected by the reflector (21) coincides with the central axis of the reflector (21).

4. The optical cavity for laser telemetry calibration according to claim 3, characterized in that: The position of the measuring tube (10) between the light inlet tube (20) and the light trap assembly (30) is a measuring portion (11), and the length of the measuring portion (11) is greater than 1.5 m, and is used to eliminate the influence of gravity on the measurement result.

5. The optical cavity for laser telemetry calibration according to claim 4, characterized in that: The light trap assembly (30) further comprises a conical light trap (31), a base (32) and an air inlet groove (33); the base (32) is arranged at the bottom of the light trap assembly (30), and the conical light trap (31) is connected to the top of the base; the conical light trap (31) is used to absorb light inside the light trap assembly (30); four air inlet grooves (33) are provided at the position where the conical light trap (31) is connected to the base (32); the air inlet grooves (33) are connected to the air inlet assembly connected to the bottom of the light trap assembly (30) and are used to transport gas into the interior of the light trap assembly (30).

6. The optical cavity for laser telemetry calibration according to claim 5, characterized in that: The gas extraction component (40) includes a tapered guide hole fixed to the bottom of the measuring cylinder (10), which is used to concentrate the gas to facilitate the determination of the gas volume; a powder collection filter is provided at the bottom of the tapered guide hole, which is used to collect powder in the extracted gas, weigh the powder, and determine the concentration of the powder by the ratio of weight to volume.

7. The optical cavity for laser telemetry calibration according to claim 6, characterized in that: A spiral mixer is connected to the inner wall of the top of the measuring cylinder (10), and a rotating motor is externally connected through the top of the measuring cylinder (10). The spiral mixer is made of a flexible material and has a size smaller than the inner radius of the measuring cylinder (10). It is used to disturb the airflow through rotation so that the aerosol entering the measuring part (11) is more uniform, thereby ensuring the accuracy of the calibration structure.

8. The optical cavity for laser telemetry calibration according to claim 7, characterized in that: A plane mirror is fixed on the top of the light-inlet cylinder (20) and is used to form a sealed environment inside the measuring cylinder (10), the light-inlet cylinder (20), and the light trap assembly (30).

9. The optical cavity for laser telemetry calibration according to claim 8, characterized in that: The gas compensation assembly connected to the top of the measuring cylinder (10) includes an air guide pipe connected to the inside of the measuring cylinder (10) and an air pump for conveying dry and clean gas into the air guide pipe; the air intake assembly connected to the bottom of the light trap assembly (30) includes an air intake pipe connected to the bottom position of the light trap assembly (30) and an air pump for conveying dry and clean gas into the air intake pipe.

10. The optical cavity for laser telemetry calibration according to claim 9, characterized in that: The volume of gas extracted by the gas extraction component (40) is the same as the volume of gas delivered to the interior of the measuring cylinder (10) by the gas compensation component connected to the top of the measuring cylinder (10) and the gas inlet component connected to the bottom of the light trap component (30).

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