Deformable mirror deformation detection device and laser processing device

Abstract

This invention provides a deformable mirror deformation detection device and a laser processing device. The deformable mirror deformation detection device includes: a deformable mirror; an emitting module for emitting a collimated parallel light beam to illuminate the deformable mirror; and a photoelectric detection module for receiving and detecting the position of the light spot. The positions of the emitting module, the photoelectric detection module, and the deformable mirror are fixed. The emitting module emits a light beam that illuminates the deformable mirror, and after reflection, illuminates the photoelectric detection module to form a first light spot. The emitted light beam illuminates the deformable mirror after its deformation, and after reflection, illuminates the photoelectric detection module to form a second light spot. The photoelectric detection module receives the coordinate information of the first and second light spots and calculates the deformation amount of the deformable mirror. Implementing the deformable mirror deformation detection device of this invention enables non-contact and rapid detection of the curvature of a deformable mirror.

Description

Technical Field

[0001] This utility model relates to the field of testing, and in particular to a deformable mirror deformation testing device and a laser processing device. Background Technology

[0002] Deformable mirrors, also known as wavefront correctors, are core components of adaptive optics systems. They consist of multiple independent control units, each precisely adjusting the mirror's morphology through an applied voltage. Their performance directly impacts the system's correction capability and accuracy. Current technologies employ contact measurement methods to measure curvature changes in deformable mirrors. A capacitance sensor is placed on the deformable mirror under test. Specifically, when the deformable mirror acts as a pole or is fitted with a conductive target, a minute displacement (d-change) causes a subtle change in capacitance. The sensor circuit accurately converts this minute change into an electrical signal, achieving high-precision displacement detection at the nanometer or even submicrometer level. Capacitive sensors are based on capacitance theory: the capacitance changes as the distance between two conducting plates changes. However, this method of measuring curvature by capacitance requires contact with the mirror surface, leading to an excessively long testing process and impacting production efficiency. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention provides a deformable mirror deformation detection device and a laser processing device to achieve non-contact and rapid detection of the curvature of deformable mirrors.

[0004] Therefore, in a first aspect, one embodiment provides a deformable mirror deformation detection device, comprising: a deformable mirror; The emitting module is used to emit a collimated parallel beam of light to illuminate the deformable mirror; The photoelectric detection module is used to receive and detect the position of the light spot; The positions of the transmitting module, the photoelectric detection module, and the deformable mirror are fixed. The transmitting module emits a light beam that shines on the deformable mirror and, after reflection, shines on the photoelectric detection module to form a first light spot. The emitted light beam shines on the deformable mirror after it has changed shape and, after reflection, shines on the photoelectric detection module to form a second light spot. The photoelectric detection module receives the coordinate information of the first light spot and the second light spot and calculates the deformation amount of the deformable mirror.

[0005] As a further optional embodiment of the deformable mirror deformation detection device, the light beam emitted by the emitting module illuminates any position on the surface of the deformable mirror except for the edge.

[0006] As a further optional solution for the deformable mirror deformation detection device, the photoelectric detection module is a four-quadrant photoelectric detector, which consists of four photodiodes with identical performance arranged in a rectangular coordinate system.

[0007] As a further optional solution for the deformation detection device of the deformable mirror, the photoelectric detection module is a light guide component and a displacement sensor, and the displacement sensor includes a photodiode array, a CCD and a PSD.

[0008] As a further optional solution for the deformable mirror deformation detection device, the light guide component is a light guide column, which has a light inlet, a light channel, and a light outlet. The light inlet and the light outlet are located at the two ends of the light channel, respectively, and the light inlet corresponds to the reflection area of ​​the deformable mirror, while the light outlet corresponds to the photoelectric detection module.

[0009] As a further alternative to the deformable mirror deformation detection device, the optical channel has a first reflective surface and a second reflective surface, which are arranged opposite to each other.

[0010] As a further optional embodiment of the deformable mirror deformation detection device, the light beam illuminates one-quarter of the deformable mirror, and the distance between the reflective surface of the deformable mirror and the photoelectric detection module is 20-50mm.

[0011] As a further optional embodiment of the deformable mirror deformation detection device, the deformable mirror has a front surface and a bottom surface, the front surface facing the emitting module and the photoelectric detection module, and the bottom surface is coated with a reflective film, which is used to reflect the incident laser and change the direction of the light path.

[0012] As a further optional embodiment of the deformable mirror deformation detection device, the light beam is characterized in that it is visible light or invisible light. In a second aspect, one embodiment provides a laser processing apparatus, including the deformable mirror deformation detection device described in any of the first aspects.

[0013] Implementing the embodiments of this utility model will have the following beneficial effects: Implementing the deformable mirror deformation detection device of this invention enables non-contact and rapid detection. The purpose of deformation in a deformable mirror.

[0014] Based on the deformable mirror deformation detection device in the above embodiments, the desired spot shape or size can be obtained, thereby improving the accuracy and efficiency of the laser processing device. Implementing the deformable mirror deformation detection device of this invention allows for real-time monitoring of changes in the deformation data of the deformable mirror during use (e.g., changes in the surface curvature of the deformable mirror). This effectively solves the problem of different deformations in the deformable mirror due to prolonged laser use, even with the same input voltage, affecting the processing effect.

[0015] According to the laser processing apparatus in the above embodiments, the workpiece is processed after the laser beam is reflected from the deformable mirror. This apparatus can monitor the deformation data (changes in the surface curvature of the deformable mirror) in real time, effectively solving the problem of inconsistent processing results caused by prolonged laser use (e.g., different deformations of the deformable mirror even with the same input voltage). Specifically, the laser processing apparatus includes a deformable mirror deformation detection device and a control unit. The deformable mirror deformation detection device monitors the first deformation data of the deformable mirror in real time. The control unit obtains the first deformation data and compares it with target deformation data. If the first deformation data is inconsistent with the target deformation data, the control unit changes the deformation of the deformable mirror until the first deformation data matches the target deformation data, ultimately adjusting the first deformation data to the target deformation data to obtain the desired spot shape or size. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] in: Figure 1 A schematic diagram of the overall structure of a deformable mirror deformation detection device according to an embodiment of the present invention is shown; Figure 2 A schematic diagram of the overall structure of another deformable mirror deformation detection device provided according to an embodiment of the present invention is shown; Figure 3 A schematic diagram of another deformable mirror deformation detection device provided according to an embodiment of the present invention is shown; Figure 4 A schematic diagram of a photoelectric detection module according to an embodiment of the present invention is shown.

[0018] Explanation of key component symbols: Deformable mirror-10; Emitting module-20; Photoelectric detection module-40; Light guide assembly-30; Light inlet-310; Light channel-320; Light outlet-330; First reflecting surface-340; Second reflecting surface-350. Detailed Implementation

[0019] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0020] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] Firstly, this utility model provides a deformable mirror deformation detection device. Please refer to [reference needed]. Figures 1-4 As shown in the figure, the deformable mirror deformation detection device includes a deformable mirror 10, a transmitting module 20, and a photoelectric detection module 40.

[0023] The transmitting module 20 is used to emit a collimated parallel light beam that illuminates the deformable mirror 10. The photoelectric detection module 40 is used to receive and detect the position of the light spot. The positions of the transmitting module 20, the photoelectric detection module 40, and the deformable mirror 10 are fixed. The light beam emitted by the transmitting module 20 illuminates the deformable mirror 10, and after reflection, illuminates the photoelectric detection module 40 to form a first light spot. The emitted light beam illuminates the deformed deformable mirror 10, and after reflection, illuminates the photoelectric detection module 40 to form a second light spot. The photoelectric detection module 40 receives the coordinate information of the first and second light spots and calculates the deformation of the deformable mirror 10.

[0024] More specifically, in this embodiment, the light emitted by the emitting module 20 illuminates the deformable mirror 10, and after reflection, the light illuminates the photoelectric detection module 40, which records the first position information of the light spot. The curvature of the deformable mirror 10 is changed to obtain the second position information of the light spot. The photoelectric detection module analyzes the deformation data of the deformable mirror based on the first and second position information, obtaining the first deformation data. The photoelectric detection module uploads this data to the control unit, compares it with the target deformation data, and determines the amount of change to adjust the deformable mirror. The control unit controls the deformable mirror until the first deformation data of the deformable mirror matches the target deformation data, thus completing the adjustment of the deformable mirror's curvature.

[0025] According to the deformable mirror deformation detection device in the above embodiments, the emitting module 20 emits a light beam that illuminates the deformable mirror 10. The beam is then reflected by the deformable mirror 10 and illuminates the photoelectric detection module 40, forming a first light spot. The photoelectric detection module 40 can be used to calculate the coordinate position of the first light spot relative to the calibration point. By changing the curvature of the deformable mirror 10, a second light spot is formed on the detector, and the photoelectric detection module 40 calculates the coordinate position of the second light spot relative to the calibration point. Implementing the deformable mirror deformation detection device of this invention enables non-contact and rapid detection of the curvature of the deformable mirror 10.

[0026] In some specific embodiments, the light beam emitted by the emitting module 20 illuminates any position on the surface of the deformable mirror 10 except for the edge.

[0027] In this embodiment, any point on the deformable mirror 10 illuminated by the transmitting module 20 is the reflection point. The edge of the deformable mirror 10 also has curvature, which can interfere with the measurement results, and therefore needs to be overcome and avoided.

[0028] like Figure 1 As shown, in some specific embodiments, the photoelectric detection module 40 is a four-quadrant photoelectric detector, which is composed of four photodiodes with the same performance arranged in a rectangular coordinate system.

[0029] Specifically, these four photodiodes are located in the four quadrants of a Cartesian coordinate system, with one photodiode in each quadrant, and the center point of each photodiode is equidistant from the origin. This arrangement allows the photodetector module 40 to detect light signals from different directions with high precision and sensitivity, and to accurately determine the position and direction of the incident light based on the intensity and distribution of the light signal received by each photodiode. This unique arrangement not only improves the spatial resolution of the photodetector module 40 but also enhances its adaptability to complex light fields, enabling it to exhibit superior performance in various application scenarios.

[0030] In this embodiment, light emitted by the emitting module 20 illuminates the deformable mirror 10. After reflection, the light illuminates the photoelectric detection module 40, which records the first position information of the light spot. The curvature of the deformable mirror 10 is changed to obtain the second position information of the light spot. The photoelectric detection module analyzes the deformation data of the deformable mirror based on the first and second position information, which is the first deformation data. The photoelectric detection module uploads the data to the control unit, compares it with the target deformation data, and determines the amount of change to adjust the deformable mirror. The control unit controls the deformable mirror until the first deformation data of the deformable mirror is the same as the target deformation data, thus completing the adjustment of the deformable mirror curvature.

[0031] For the operational principle of the photoelectric detection module 40, please refer to [link / reference]. Figure 3 : For the operational principle of the photoelectric detection module 40, please refer to [link / reference]. Figure 3 , Figure 3 In the diagram, the current intensities in the four quadrants are I1, I2, I3, and I4, respectively: When the light spot is at the center, the light intensity received in all four quadrants is equal, and the total current I... tot The relationship between the formulas and the currents in the four quadrants is as follows: .

[0032] If the light spot shifts horizontally by Δx, the illumination intensity received by the left and right quadrants will no longer be equal, resulting in a difference in the photocurrent generated by the left and right quadrants; if the light spot shifts vertically by Δy, the illumination intensity received by the upper and lower quadrants will no longer be equal, resulting in a difference in the photocurrent generated by the upper and lower quadrants.

[0033] Horizontal differential signal D x and vertical differential signal D y The definition is as follows:

[0034] Finally, it was found that within a small displacement range (Δx, Δy < spot diameter), the differential signal has a linear relationship with the displacement: , .

[0035] Among them, K x K y It is a sensitivity constant (unit: length) determined by the spot size and the photoelectric detection module 40.

[0036] like Figure 2 As shown, in some specific embodiments, the photoelectric detection module 40 is a light guide component 30 and a displacement sensor, which includes a photodiode array, a CCD, and a PSD.

[0037] In this example, it is generally assumed that the first light spot, the second light spot, and the origin of the coordinate system are on the same straight line. Light emitted from the emitting module 20 illuminates the deformable mirror 10. After reflection, the light enters the light guide assembly 30, which acts as a "mechanical-optical amplifier." The light exits from the light guide assembly 30 and illuminates the photoelectric detection module 40 at a preset position. The photoelectric detection module 40 then records the first position information 'a' of the light spot. By changing the curvature of the deformable mirror 10, the second position information 'b' of the light spot is obtained. The photoelectric detection module 40, based on its internal preset calculation program, inputs the first position information 'a' and the second position information 'b' to calculate the change in curvature and obtain the first deformation data. Implementing the deformable mirror deformation detection device of this invention enables non-contact and rapid detection of the curvature change of the lens.

[0038] In this embodiment, the larger the value of L, the larger the values ​​of a and b, resulting in larger a and b values ​​obtained on the photoelectric detection module 40. Larger a and b values ​​mean lower accuracy requirements for them. The light guide component 30 can be used to increase the value of L, allowing for an increase in the value of L without increasing the size of the deformable mirror deformation detection device in this invention. In other words, through the design of the light guide component 30, the deformable mirror deformation detection device in this invention can be miniaturized.

[0039] A photodiode array is an optoelectronic device composed of multiple photodiodes arranged in a specific manner. Its working principle is based on the photoelectric effect, where light irradiates a semiconductor material, generating electron-hole pairs and thus producing a current. The magnitude of the current is directly proportional to the intensity of the irradiated light. In this embodiment, the position of the light spot is calculated by calculating the current generated by two light spots, thereby quickly obtaining the value Δx. Then, using a pre-set program, the value Δθ is quickly calculated using the formula described above.

[0040] CCDs utilize the photoelectric effect of semiconductors. When light shines on a CCD chip, it generates an electric charge. The charge is then transferred to the storage area through the action of an electric field, and finally, the charge signal is converted into a digital signal through an analog-to-digital converter.

[0041] A PSD (Position Sensitive Detector) is a photosensitive sensor based on the lateral photoelectric effect. It can detect the position of an incident light spot on a photosensitive surface and is widely used in light position detection.

[0042] In some specific embodiments, the light guide component 30 is a light guide post, which has a light inlet 310, a light channel 320 and a light outlet 330. The light inlet 310 and the light outlet 330 are located at the two ends of the light channel 320, and the light inlet 310 corresponds to the reflection area of ​​the deformable mirror 10, and the light outlet 330 corresponds to the photoelectric detection module 40.

[0043] In this embodiment, light enters the light channel 320 from the light inlet 310 of the light guide assembly 30, passes through the light channel 320, exits from the light outlet 330, and finally enters the photoelectric detection module 40. The curvature change of the deformable mirror 10 is extremely small. The reflection angles of light rays reflected from the deformable mirror 10 on two separate occasions are different, but the difference between the two reflection angles is small. The reflected light can only be accurately identified at a relatively long distance. The light guide assembly 30 is provided to miniaturize the deformable mirror deformation detection device. Miniaturization of the device can ensure good measurement accuracy without occupying a large space. The main function of the light channel 320 in the light guide assembly 30 is to increase the distance of the light rays, thereby making the difference in the position of the light spot between the two irradiations more obvious.

[0044] For example, if the angle between two light rays at the same location is 1°, the light spots formed by the two light rays illuminating a plane 1 meter away will be very close, the light spots formed at 10 meters away will be clearly distinguishable, and the light spots formed at 100 meters away will be even farther apart. By calculating the angle between the two light rays from the light spot distances obtained at 1 meter, 10 meters, and 100 meters, the result obtained from the light spot distance at 100 meters will definitely be closer to 1°.

[0045] According to geometric relations: Δx = L * Δθ, where: Δx, the displacement of the laser point on the sensor surface; L, the distance light travels; Δθ, the minute rotation angle of the mirror.

[0046] Therefore, once the values ​​of Δx and L are determined, the value of Δθ can be derived, thus obtaining the deformation curvature of the deformable mirror 10.

[0047] Furthermore, as can be seen from the above formula, L is a constant, so the larger the value of L, the larger the value of Δx can be even if Δθ changes very little.

[0048] In some specific embodiments, the optical channel 320 has a first reflective surface 340 and a second reflective surface 350, which are arranged opposite to each other.

[0049] The cross-section of the optical channel 320 can be circular, elliptical, rectangular, or other irregular shapes, and its size and shape can be adjusted according to the light transmission requirements of the actual application. The distance between the first reflecting surface 340 and the second reflecting surface 350 can be optimized according to the design requirements of the optical system to achieve the best light transmission efficiency and optical performance.

[0050] In some specific embodiments, the light beam illuminates a quarter of the deformable mirror 10, and the distance between the reflective surface of the deformable mirror 10 and the photoelectric detection module 40 is 20-50 mm.

[0051] In this embodiment, the distance between the emission point and the photoelectric detection module 40 is determined to achieve consistency in product performance.

[0052] L = d * n, where d is the distance between the first reflecting surface 340 and the second reflecting surface 350, and n is the number of times the light is reflected.

[0053] Because the curvature Δθ of the deformable mirror 10 changes within a very small range, the number of reflections (n) of the light rays reflected twice in the light guide assembly 3030 is almost the same. With a d value of 20-50 mm, the change in Δx can be clearly observed. In this embodiment, the minimum angular change to be detected is 0.0003°.

[0054] In some specific embodiments, the deformable mirror 10 has a front surface and a bottom surface. The front surface faces the emitting module 20 and the photoelectric detection module 40, and the bottom surface is coated with a reflective film. The reflective film is used to reflect the incident laser and change the direction of the light path.

[0055] In this embodiment, the specific structure of the deformable mirror 10 is detailed. The bottom surface of the deformable mirror 10 can change its deformation rate by voltage, thereby achieving the effect of changing the optical path.

[0056] In some specific embodiments, the light beam is visible light or invisible light. The wavelength range of light is 380nm-750nm, which belongs to visible light, including blue light, violet light, green light and red light. Visible light is easy for inspectors to observe.

[0057] It should be noted that the transmitting module 20 can also emit invisible light. Anything that the photoelectric detection module 4040 can identify falls within the protection scope of this utility model.

[0058] Secondly, this utility model provides a laser processing apparatus, including the deformable mirror deformation detection device according to any one of the first aspects.

[0059] According to the laser processing apparatus in the above embodiments, the workpiece is processed after the processing laser is reflected off the deformable mirror.

[0060] According to the laser processing apparatus in the above embodiments, the workpiece is processed after the laser beam is reflected from the deformable mirror. This apparatus allows for real-time monitoring of the deformation data changes of the deformable mirror during use (e.g., changes in the surface curvature of the deformable mirror), effectively solving the problem of different deformations of the deformable mirror due to prolonged laser use, even with the same input voltage, affecting processing results. Specifically, the laser processing apparatus includes a deformable mirror deformation detection device and a control unit. The deformable mirror deformation detection device monitors the first deformation data of the deformable mirror in real time. The control unit obtains the first deformation data and compares it with target deformation data. If the first deformation data is inconsistent with the target deformation data, the control unit changes the deformation of the deformable mirror until the first deformation data matches the target deformation data, ultimately adjusting the first deformation data to the target deformation data. This allows for obtaining the desired spot shape or size, thereby improving the accuracy and efficiency of the laser processing apparatus.

[0061] Meanwhile, in this embodiment, the other side of the laser-reflecting surface of the deformable mirror is equipped with a piezoelectric ceramic that can generate deformation. The piezoelectric ceramic generates different deformations according to the input voltage, thereby changing the curvature of the deformable mirror. However, under long-term use, the piezoelectric ceramic will produce the following problems: ① Applying the same voltage to the piezoelectric ceramic will produce different deformations; ② The fixing adhesive will age and change the stress, causing the piezoelectric ceramic to produce different deformations even when the same voltage is applied. Of course, there are other situations that may affect the curvature of the deformable mirror, thus affecting the processing effect. Therefore, the above-mentioned device can monitor the curvature change of the deformable mirror in real time, which can effectively solve the problem that the deformation of the deformable mirror will produce different deformations when the same voltage is applied due to the long-term operation of the laser, thus affecting the processing effect.

[0062] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A deformation mirror deformation detection device characterized by comprising: include: Deformable mirror; The emitting module is used to emit a collimated parallel beam of light to illuminate the deformable mirror; The photoelectric detection module is used to receive and detect the position of the light spot; The positions of the transmitting module, the photoelectric detection module, and the deformable mirror are fixed. The transmitting module emits a light beam that shines on the deformable mirror and, after reflection, shines on the photoelectric detection module to form a first light spot. The emitted light beam shines on the deformable mirror after it has changed shape and, after reflection, shines on the photoelectric detection module to form a second light spot. The photoelectric detection module receives the coordinate information of the first light spot and the second light spot and calculates the deformation amount of the deformable mirror.

2. The apparatus of claim 1, wherein The beam emitted by the emission module illuminates any position on the surface of the deformable mirror except for the edge.

3. The apparatus of claim 1, wherein the at least one processor is configured to determine the deformation of the mirror based on the at least one of the first and second signals. The photoelectric detection module is a four-quadrant photoelectric detector, which consists of four photodiodes with identical performance arranged in a rectangular coordinate system.

4. The deformable mirror deformation detection device as described in claim 1, characterized in that, The photoelectric detection module comprises a light guide component and a displacement sensor, wherein the displacement sensor includes a photodiode array, a CCD, and a PSD.

5. The deformable mirror deformation detection device as described in claim 4, characterized in that, The light guide component is a light guide column, which has a light inlet, a light channel, and a light outlet. The light inlet and the light outlet are located at the two ends of the light channel, respectively. The light inlet corresponds to the reflection area of ​​the deformable mirror, and the light outlet corresponds to the photoelectric detection module.

6. The deformable mirror deformation detection device as described in claim 5, characterized in that, The optical channel has a first reflective surface and a second reflective surface, which are arranged opposite to each other.

7. A deformable mirror deformation detection device as described in claim 3 or 4, characterized in that, The light beam illuminates one-quarter of the deformable mirror, and the distance between the reflective surface of the deformable mirror and the photoelectric detection module is 20-50mm.

8. A deformable mirror deformation detection device as described in claim 3 or 4, characterized in that, The deformable mirror has a front surface and a bottom surface. The front surface faces the emitting module and the photoelectric detection module. The bottom surface is coated with a reflective film, which is used to reflect the incident laser and change the direction of the light path.

9. A deformable mirror deformation detection device as described in claim 3 or 4, characterized in that, The light beam can be visible or invisible.

10. A laser processing apparatus, characterized in that, The deformable mirror deformation detection device includes any one of claims 1-9.

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