Reflection-based laser beam detection system and method thereof

Abstract

The application discloses a kind of laser beam detection system and method based on reflection, including two reflecting prisms, reflecting prism back is conical prism, front is plane mirror.Two reflecting prisms are placed oppositely, and the part of plane mirror that contacts light is parallel to each other, the application utilizes two reflecting prisms, and the part of plane mirror that contacts light is parallel to each other, according to the difference of laser power, the relative position of two lenses is relatively moved, to ensure that incident beam and emergent beam are not transmitted in the mode of propagation, and according to the height of power, the number of times of turning of light beam is determined, the relative distance of two reflecting prisms is adjusted, and the angle of adjusting the relative horizontal position of two lenses is adjusted, the purpose is to realize the position of incident spot and emergent spot unchanged, convenient to use, realize whether normal incidence or oblique incidence can be transmitted spot in the position of different prisms, and the energy of each beam of light of non-use of transmission is reduced.

Description

Technical Field

[0001] This invention belongs to the field of detection system technology, specifically relating to a laser beam detection system and method based on reflection. Background Technology

[0002] With the booming development of industrial laser processing, the application range of lasers is becoming increasingly wide, and the power is gradually increasing. As the requirements for laser processing quality continue to rise, the demands on laser beam quality are also increasing. Therefore, the detection of laser beam quality is crucial. Laser beam quality detection includes collimated beam detection and focused beam detection. There are many methods for collimated beam detection, including reflection and transmission methods, as these methods do not introduce additional aberrations into the optical path and have no special requirements on the optical path length. However, for focused beam detection, the detection method cannot be arbitrarily chosen. In the focused optical path, the focusing position of the beam is determined by the working distance of the focusing system, while the size of the focused spot is determined by the incident spot of the focusing system. The detection... To simultaneously meet these two requirements without introducing additional aberrations, conventional methods employ dual-wedge reflection attenuation and matched absorption attenuators to reduce the energy of the laser beam. However, the drawback is that the dual-wedge design must be tailored to the actual incident spot size and optical path length. The optical path of the deflected optical path must be shorter than the optical path of the focusing system to accurately detect the focused spot size. Since the deflected optical path typically involves a 90-degree deflection, reducing the optical path length is difficult. Matched absorption attenuation, due to the inherent properties of the material (absorbing most light and transmitting only a small portion), results in minimal material damage and is therefore unsuitable for attenuating high-power lasers. Furthermore, it introduces additional aberrations when the numerical aperture of the beam is large. Therefore, we propose a reflection-based laser beam detection system and method to address the problems mentioned in the background. Summary of the Invention

[0003] The purpose of this invention is to provide a reflection-based laser beam detection system and method to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a laser beam detection system based on reflection, comprising two reflecting prisms, wherein the back of the reflecting prism is a conical prism and the front is a plane mirror, the plane mirrors of the two reflecting prisms are placed opposite each other, the parts of the plane mirrors that contact the light are parallel to each other, and light-absorbing devices are added behind the reflecting prisms to absorb the transmitted fission beam.

[0005] A laser emitter is used to emit a beam of light;

[0006] The relationship between the incident angle of the beam and the tilt angle of the reflecting prism is α = 90° - θ. The number of reflections is defined as n, which is the number of reflections after passing through the two reflecting prisms. The distance between the two reflecting prisms is t. The size of the light spot after the beam is reflected by the reflecting prism is D. The distance between the incident beam and the outgoing beam is H. The corresponding relationship is sin(θ) = H / (2*n*t), where H ≥ 2D. The reflection-transmission attenuation ratio of the reflecting prism is 1:24. Based on the magnitude of the incident beam power, the values ​​of n, t, and θ are adjusted to obtain the attenuated beam energy value of 1mW. The size of the reflecting prism is ≥ 4D. The distance between the incident beam and the outgoing beam is H.

[0007] This invention also provides a detection method for a reflection-based laser beam detection system, specifically including the following steps:

[0008] S1. The relative positions of the two reflecting prisms are moved to ensure that both the incident beam and the outgoing beam propagate out without transmission. The number of folds of the beam, i.e. the attenuation ratio, is determined by the power of the laser emitter. The relative position of the reflection center of the beam each time is the size of the two light spots, i.e., the size of the light spot is D. Then, the distance between the position of the light spot that is next incident on this lens after reflection and the first light spot is ≥2D.

[0009] To ensure that the incident and exit positions of the laser are consistent, the relative distance between the two reflecting prisms and the angle of the relative horizontal position of the two lenses are adjusted. The purpose is to keep the positions of the incident and exit spots unchanged.

[0010] The attenuation of the laser beam is achieved by using double even-order reflection. At different positions of the two reflecting prisms that transmit the laser, i.e., on the rear surface of the reflecting prisms, a conical mirror with a ≥ triangular shape is used to achieve beam splitting.

[0011] S2. The number of edges and the bottom size of the cone prism depend on the size of the testable light spot. The bottom size of the cone prism is 1 / 2 of the light spot diameter, so that the light spot can be split at different edge positions regardless of whether the beam is incident normally or obliquely, thus reducing the energy of each beam.

[0012] S3. Add light-absorbing devices behind the cone prism to absorb the transmitted light beam and reduce its impact on the main optical path.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a laser beam detection system and method based on reflection. The present invention utilizes two reflecting prisms placed opposite each other, with the light-contacting parts of the lenses being parallel to each other. Depending on the laser power, the relative positions of the two lenses are moved to ensure that both the incident and outgoing beams propagate without transmission. The number of folds of the beam is determined by the power level. To ensure that the incident and outgoing positions of the laser are consistent, the relative distance between the two reflecting prisms and the angle of the relative horizontal positions of the two lenses are adjusted. The purpose is to keep the positions of the incident and outgoing beams constant, facilitating use. Whether the incident beam is normal or oblique, the transmitted beam can be split at different prism positions, reducing the energy of each unused beam of transmitted light. Light-absorbing devices are added behind the prisms to absorb the transmitted beams, reducing the impact on the main optical path. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the optical path transmission parameters of the present invention;

[0015] Figure 2 This is a schematic diagram of the parallel optical path transmission with two reflections according to the present invention;

[0016] Figure 3 This is a schematic diagram of the parallel optical path four-reflection transmission of the present invention;

[0017] Figure 4 This is a schematic diagram of the parallel optical path six-reflection transmission of the present invention;

[0018] Figure 5 This is a schematic diagram of the first beam distribution of the triangular pyramid prism of the present invention;

[0019] Figure 6 This is a schematic diagram of the second beam distribution of the triangular pyramid prism of the present invention;

[0020] Figure 7 This is a schematic diagram of the first beam distribution of the pentagonal pyramidal prism of the present invention;

[0021] Figure 8 This is a schematic diagram of the second beam distribution of the hexagonal pyramidal prism of the present invention;

[0022] Figure 9 This is a schematic diagram of the light spot distribution after passing through the triangular pyramid prism of the present invention;

[0023] Figure 10 This is a schematic diagram of the light spot distribution after passing through the pentaprism prism of the present invention;

[0024] Figure 11 This is a schematic diagram of the focused optical path transmission of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Please see Figure 1-11 The following is an example: A laser beam detection system based on reflection includes two reflecting prisms. The back of each reflecting prism is a conical prism, and the front is a plane mirror. The plane mirrors of the two reflecting prisms are placed opposite each other, and the parts of the plane mirrors that come into contact with the light are parallel to each other. A light-absorbing device is added behind each reflecting prism to absorb the transmitted fission beam. A laser emitter is used to emit the beam.

[0027] The relationship between the incident angle of the beam and the tilt angle of the reflecting prism is α = 90° - θ. The number of reflections is defined as n, which is the number of reflections after passing through the two reflecting prisms. The distance between the two reflecting prisms is t. The size of the light spot after the beam is reflected by the reflecting prism is D. The distance between the incident beam and the outgoing beam is H. The corresponding relationship is sin(θ) = H / (2*n*t), where H ≥ 2D. The reflection-transmission attenuation ratio of the reflecting prism is 1:24. Based on the magnitude of the incident beam power, the values ​​of n, t, and θ are adjusted to obtain the attenuated beam energy value of 1mW. The size of the reflecting prism is ≥ 4D. The distance between the incident beam and the outgoing beam is H.

[0028] This invention also provides a detection method for a reflection-based laser beam detection system, specifically including the following steps:

[0029] S1. Depending on the power of the laser emitter, the relative positions of the two reflecting prisms are moved to ensure that both the incident beam and the outgoing beam propagate out without transmission. The number of folds of the beam, i.e. the attenuation ratio, is determined by the power of the laser emitter. The relative position of the reflection center of the beam each time is the size of the two light spots, i.e., the size of the light spot is D. Then, the distance between the position of the light spot that is next incident on this lens after reflection and the first light spot is ≥2D.

[0030] To ensure that the incident and exit positions of the laser are consistent, the relative distance between the two reflecting prisms and the angle of the relative horizontal position of the two lenses are adjusted. The purpose is to keep the positions of the incident and exit spots unchanged.

[0031] The attenuation of the laser beam is achieved by using double even-order reflection. At different positions of the two reflecting prisms that transmit the laser, i.e., on the rear surface of the reflecting prisms, a conical mirror with a ≥ triangular shape is used to achieve beam splitting.

[0032] S2. The number of edges and the bottom size of the cone prism depend on the size of the testable light spot. The bottom size of the cone prism is 1 / 2 of the light spot diameter, so that the light spot can be split at different edge positions regardless of whether the beam is incident normally or obliquely, thus reducing the energy of each beam.

[0033] S3. Add light-absorbing devices behind the cone prism to absorb the transmitted light beam and reduce its impact on the main optical path.

[0034] The two reflecting prisms and the light-absorbing device behind them are integrated into one unit. This integrated design, along with a matching attenuation scheme, allows for the measurement of light spots with diameters as low as 40µm, supporting real-time exposure and gain adjustment. The system can sample continuous visible laser spots, analyze them to obtain the laser spot center, radius, ellipticity, etc., and display the light intensity energy field in two and three dimensions.

[0035] It can be widely used in applications requiring laser spot shape detection, such as laser production, maintenance, and other laser applications. It is also commonly used for optical device quality inspection, laser cavity mirror adjustment, external optical path collimation, and fiber alignment and coupling analysis. Currently, it is a mature product being promoted in the market, offering excellent value for money and gaining widespread customer recognition.

[0036] Customizable spot size and power:

[0037] We can customize spot analyzers to meet different customer needs, including different laser beam diameters and laser powers.

[0038] Basic model: Can test spot sizes from 40um to 4.5mm in diameter;

[0039] Customized Model A: Can measure light spots with a diameter of approximately 6mm;

[0040] Customized version B: Can measure light spots with a diameter of approximately 9mm.

[0041] The basic model can test low-power milliwatt-level lasers, and can also be customized to meet high-power laser testing needs. Depending on the customer's laser power, a suitable attenuation solution can be provided, up to 400W for high-power applications.

[0042] In summary, compared with the prior art, this invention utilizes two reflecting prisms placed opposite each other, with the light-contacting portions of the lenses parallel to each other. Depending on the laser power, the relative positions of the two lenses are adjusted to ensure that both the incident and outgoing beams propagate without transmission. Furthermore, the number of folds in the beam is determined by the power level. To ensure that the incident and outgoing laser positions are consistent, the relative distance between the two reflecting prisms and the angle of their relative horizontal positions are adjusted. The purpose is to maintain the constant positions of the incident and outgoing beams, facilitating use. Whether the light is incident directly or obliquely, the transmitted beam can be split at different prism positions, reducing the energy of each unused beam. Light-absorbing devices are added behind the prisms to absorb the transmitted beams, reducing their impact on the main optical path.

[0043] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A detection method for a reflection-based laser beam detection system, characterized in that: The reflection-based laser beam detection system includes two reflecting prisms. The back of each reflecting prism is a conical prism, and the front is a plane mirror. The plane mirrors of the two reflecting prisms are placed opposite each other, and the parts of the plane mirrors that come into contact with the light are parallel to each other. A light-absorbing device is added behind each reflecting prism to absorb the transmitted fission beam. The relationship between the incident angle of the beam and the tilt angle of the reflecting prism is α = 90° - θ. The number of reflections is the number of reflections after passing through the two reflecting prisms, defined as n. The distance between the two reflecting prisms is t. The size of the light spot after the beam is reflected by the reflecting prism is D. The distance between the incident beam and the outgoing beam is H. The corresponding relationship is sin(θ) = H / (2*n*t), H≥2D. The reflection-transmission attenuation ratio of the reflecting prism is 1:

24. According to the magnitude of the incident power of the beam, the values ​​of n, t, and θ are adjusted to obtain the attenuated beam energy value of 1mW. The size of the reflecting prism is ≥4D. The detection method specifically includes the following steps: S1. The relative positions of the two reflecting prisms are moved to ensure that both the incident beam and the outgoing beam propagate out without transmission. The number of folds of the beam, i.e. the attenuation ratio, is determined by the power of the laser emitter. The relative position of the reflection center of the beam each time is the size of the two light spots, i.e., the size of the light spot is D. Then, the distance between the position of the light spot that is next incident on this lens after reflection and the first light spot is ≥2D. To ensure that the incident and exit positions of the laser are consistent, the relative distance between the two reflecting prisms and the angle of the relative horizontal position of the two lenses are adjusted. The purpose is to keep the positions of the incident and exit spots unchanged. The attenuation of the laser beam is achieved by using double even-order reflection. At different positions of the two reflecting prisms that transmit the laser beam, i.e., on the rear surface of the reflecting prisms, a triangular pyramidal prism is used to split the laser beam. S2. The number of edges and the bottom size of the cone prism depend on the size of the testable light spot. The bottom size of the cone prism is 1 / 2 of the light spot diameter, so that the light spot can be split at different edge positions regardless of whether the beam is incident normally or obliquely, thus reducing the energy of each beam. S3. Add light-absorbing devices behind the cone prism to absorb the transmitted light beam and reduce its impact on the main optical path.

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