Laser power tuning attenuation device and annealing apparatus

Abstract

The application provides a laser power tuning attenuation device and an annealing device, the laser power tuning attenuation device comprises a reflective polarization rotation unit and a polarization beam splitter, and the incidence planes of the mirrors in the reflective polarization rotation unit are located in the same plane; the reflective polarization rotation unit is used for receiving incident light and is rotatably arranged around the optical axis of the incident light, and the phase delay amount of the mutually perpendicular s light and p light of the incident light relative to the incidence plane after the reflective polarization rotation unit is an odd multiple of 180°, so that the polarization direction of the outgoing light after the reflective polarization rotation unit is rotated by a certain angle relative to the polarization direction of the incident light, and the outgoing light is reflected by the polarization beam splitter to obtain output light after power attenuation. The technical scheme of the application can realize accurate control of laser power attenuation in a high-power laser annealing device, and can also maintain the stability of the size and directivity of the output light, thereby improving the annealing process index.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser technology, in particular to a laser power tuning attenuation device and an annealing equipment. BACKGROUND

[0002] At present, laser is widely used in many fields. In the use process of the laser, due to the characteristics of laser components or the requirements of the light splitting system, or the processed materials need different laser power, etc., the size of the laser energy needs to be adjusted. In order to realize this function, a laser power tuning attenuation device is needed to quickly complete the tuning and attenuation of the laser power.

[0003] For example, when the IC process technology is transformed from 28nm node to F14nm node, in order to solve the short channel effect caused by the reduction of gate length, the source and drain need to be first ion implanted to form an ultra shallow junction (USJ). At present, the manufacturers usually choose laser annealing to process and manufacture it, and in order to avoid the pattern effect, a 10.6μm wavelength CO2 laser source is usually used to make Brewster p-polarized incident, and the laser power used is as high as kilowatt level. In the mid-infrared laser annealing equipment (i.e. high-power laser annealing equipment) applied to this demand, the laser power tuning function inside the CO2 gas laser will affect the pointing stability and size stability of the output laser spot, and then affect the final annealing process index. Therefore, in this annealing light path system, a laser power tuning attenuation device outside the laser is needed to realize the tuning of the final output optical power on the basis of keeping the output power of the laser unchanged.

[0004] The laser power tuning attenuation device usually adopts the scheme of half-wave plate plus polarization beam splitter prism. By rotating the half-wave plate around the optical axis, the polarization direction of the incident light is deflected, and then the polarization splitting characteristics of the polarization beam splitter prism are used to realize the change of the output optical power. However, in the high-power laser annealing equipment, due to the large incident light power, the damage threshold of the lens system of the traditional half-wave plate plus polarization beam splitter prism is low, and it cannot withstand high-power laser. Therefore, the scheme of half-wave plate plus polarization beam splitter prism is not suitable for high-power laser annealing equipment.

[0005] Therefore, how to improve the existing laser power tuning attenuation device to realize the accurate control of the laser power attenuation in the high-power laser annealing equipment, and at the same time maintain the stability of the size and pointing direction of the output light, so as to improve the annealing process index (such as annealing uniformity) is a problem to be solved at present. SUMMARY

[0006] The application aims to provide a laser power tuning attenuation device and annealing equipment, which can realize precise control of laser power attenuation in high-power laser annealing equipment, and maintain the stability of the size and directivity of output light, thereby improving the annealing process index (such as annealing uniformity).

[0007] To achieve the above-mentioned purpose, the application provides a laser power tuning attenuation device, which comprises a reflective polarization rotation unit and a polarization beam splitter mirror, the reflective polarization rotation unit comprises at least two mirrors, and the incident surfaces of all the mirrors are located in the same plane; the reflective polarization rotation unit is used for receiving incident light, the reflective polarization rotation unit is rotatably arranged around the optical axis of the incident light, the phase delay amount of s light and p light perpendicular to each other relative to the incident surface after the incident light passes through the reflective polarization rotation unit is an odd multiple of 180°, so that the polarization direction of the outgoing light after the incident light passes through the reflective polarization rotation unit is rotated by a certain angle relative to the polarization direction of the incident light, and the outgoing light is reflected by the polarization beam splitter mirror to obtain output light with power attenuation.

[0008] Optionally, the base of the mirror and the base of the polarization beam splitter mirror are both made of high-power-resistant material, and both have a power resistance greater than or equal to 500 W per square centimeter.

[0009] Optionally, the base of the mirror comprises Cu or Au.

[0010] Optionally, the base of the polarization beam splitter mirror comprises at least one of Cu, ZnSe, BaF2 and CaF2.

[0011] Optionally, the surface of the mirror is coated with at least one film, so that the s light and p light perpendicular to each other relative to the incident surface have a phase delay amount.

[0012] Optionally, the film has a single-layer structure or a structure stacked by at least two layers, and each layer is made of at least one of ZnSe, Ge and a fluorine compound.

[0013] Optionally, the reflective polarization rotation unit comprises at least three mirrors, and the direction of the outgoing light is coaxial with the direction of the incident light.

[0014] Optionally, when the reflective polarization rotation unit is rotated to an angle θ between the incident surface and the polarization direction of the incident light, the polarization direction of the outgoing light is rotated by an angle 2θ relative to the polarization direction of the incident light.

[0015] Optionally, the back surface of the mirror is provided with a cooling water flow channel.

[0016] Optionally, all the reflecting mirrors are arranged on the same base plate, and the gravity center of the reflecting polarization rotating unit is on the optical axis of the incident light.

[0017] Optionally, the laser power tuning attenuation device further comprises a rotating unit and a locking unit, the rotating unit drives the reflecting polarization rotating unit to rotate around the optical axis of the incident light, and the locking unit locks the reflecting polarization rotating unit at a predetermined angle.

[0018] The application provides an annealing device comprising a laser and the laser power tuning attenuation device, and the incident light emitted by the laser is subjected to power tuning attenuation by the laser power tuning attenuation device.

[0019] Optionally, the annealing device further comprises a detecting unit for detecting the power of the output light and adjusting the rotating angle of the reflecting polarization rotating unit according to the detection result.

[0020] Compared with the prior art, the technical scheme of the application has the following beneficial effects:

[0021] 1. The laser power tuning attenuation device can tune and attenuate the laser power by the laser power tuning attenuation device, replace the power tuning of the laser itself in the laser annealing device with the external power tuning, maintain the stability of the size and directivity of the output light, and improve the annealing process index (e.g. annealing uniformity).

[0022] 2. The annealing device can tune and attenuate the laser power by the laser power tuning attenuation device, maintain the stability of the size and directivity of the output light, improve the annealing process index (e.g. annealing uniformity), and meet the demand of the high-power mid-infrared laser annealing device. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structural schematic view of the laser power tuning attenuation device of the first embodiment of the application;

[0024] Figure 2 is Figure 1The rotating schematic diagram of the reflective polarization rotation unit in the shown laser power tuning attenuation device;

[0025] Figure 3 The trend chart of the p light power of the outgoing light of an embodiment of the present application versus the included angle between the incident plane of the mirror and the polarization direction of the incident light;

[0026] Figure 4 The trend chart of the s light power of the outgoing light of an embodiment of the present application versus the included angle between the incident plane of the mirror and the polarization direction of the incident light;

[0027] Figures 5a to 5d The schematic diagram of the incident light spot distribution and the polarization direction change in the optical simulation software of an embodiment of the present application;

[0028] Figure 6 The comparison chart of the measured data and the theoretical calculation values of the test bench built in an embodiment of the present application;

[0029] Figure 7 The structural schematic diagram of the laser power tuning attenuation device of the second embodiment of the present application;

[0030] Figure 8 The structural schematic diagram of the laser power tuning attenuation device of the third embodiment of the present application.

[0031] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the present application and, together with the description, further serve to explain the principles of the application and to enable a person skilled in the relevant art(s) to make and use the application. Figures 1 to 8 The reference signs in the accompanying drawings are explained as follows:

[0032] 11-laser; 121-first mirror; 122-second mirror; 123-third mirror; 124-fourth mirror; 125-fifth mirror; 126-sixth mirror; 13-polarization beam splitter; 14-power meter. DETAILED DESCRIPTION

[0033] To make the objects, advantages and features of the present application clearer, the following further describes the laser power tuning attenuation device and the annealing equipment proposed by the present application. It should be noted that the accompanying drawings are all in a very simplified form and all use non-precise proportions, which are only used to facilitate and clarify the purpose of assisting the description of the embodiments of the present application.

[0034] The embodiment of the present application provides a laser power tuning attenuation device, which comprises a reflective polarization rotation unit and a polarization beam splitter mirror, the reflective polarization rotation unit comprises at least two mirrors, and the incidence planes of all the mirrors are located in the same plane; the reflective polarization rotation unit is used for receiving incident light, the reflective polarization rotation unit is rotatably arranged around the optical axis of the incident light, the phase delay amount of s light and p light which are perpendicular to each other relative to the incidence plane after the incident light passes through the reflective polarization rotation unit is an odd multiple of 180°, so that the polarization direction of the outgoing light after the incident light passes through the reflective polarization rotation unit is rotated by a certain angle relative to the polarization direction of the incident light, and the outgoing light is reflected by the polarization beam splitter mirror to obtain output light after power attenuation.

[0035] Hereinafter, the laser power tuning attenuation device provided by the embodiment will be described in detail. Figures 1 to 8 The laser power tuning attenuation device provided by the embodiment will be described in detail.

[0036] The reflective polarization rotation unit is rotatably arranged around the optical axis of the incident light emitted by the laser, and the rotation angle range is 0°-360°.

[0037] In the middle infrared laser annealing equipment (i.e. high-power laser annealing equipment), the power of the middle infrared incident light emitted by the laser to the reflective polarization rotation unit is very high, for example, greater than or equal to 500W.

[0038] The reflective polarization rotation unit comprises at least two mirrors. Figure 1 In the embodiment shown in the figure, the reflective polarization rotation unit comprises four mirrors, i.e. a first mirror 121, a second mirror 122, a third mirror 123 and a fourth mirror 124.

[0039] In order to be able to withstand high-power incident light, the base of the mirror and the base of the polarization beam splitter mirror are both made of high-power resistant material, and have a small absorption rate in the middle infrared wave band, so that the mirror and the polarization beam splitter mirror have a high power damage threshold. Preferably, the power resistance of the base of the mirror and the base of the polarization beam splitter mirror reaches more than or equal to 500W per square centimeter.

[0040] The base of the mirror can comprise Cu or Au, and the base of the polarization beam splitter mirror can comprise at least one of Cu, ZnSe, BaF2 and CaF2. It should be noted that the base of the mirror and the base of the polarization beam splitter mirror are not limited to the above-mentioned types, for example, the base of the polarization beam splitter mirror can also contain Cu and WC at the same time.

[0041] The incidence planes of all the mirrors are located in the same plane.

[0042] And, a surface of the mirror is coated with at least one film to cause a certain phase delay amount between mutually perpendicular s light and p light of the incident light with respect to an incident plane of the mirror.

[0043] Wherein, the film is a single layer structure or a structure of at least two layers stacked, and the material of each layer structure can include at least one of ZnSe, Ge and a compound of a fluorine family; the number of layers of the film and the material of each layer structure and other characteristics cause a certain phase delay amount between mutually perpendicular s light and p light of the incident light with respect to an incident plane of the mirror.

[0044] The incident light is linearly polarized light, and by rotating the reflective polarization rotation unit around the optical axis of the incident light, an included angle between the polarization direction of the incident light and the incident plane of the reflective polarization rotation unit is generated.

[0045] By setting the phase delay amount of mutually perpendicular s light and p light of the incident light with respect to the incident plane of the mirror after passing through the reflective polarization rotation unit to be an odd multiple (for example, 180° or 540°) of 180°, and by rotating the reflective polarization rotation unit around the optical axis of the incident light, the polarization direction of the outgoing light after passing through the reflective polarization rotation unit can be rotated by a certain angle with respect to the polarization direction of the incident light, and the outgoing light is reflected by the polarization beam splitter mirror to obtain the output light after power attenuation.

[0046] Wherein, since the incident light is linearly polarized light, the phase delay amount of mutually perpendicular s light and p light of the incident light with respect to the incident plane of the mirror and the rotation of the reflective polarization rotation unit around the optical axis of the incident light can ensure that the outgoing light is linearly polarized light, and ensure that the polarization direction of the outgoing light is rotated by a certain angle with respect to the polarization direction of the incident light.

[0047] And, the total phase delay amount of the mutually perpendicular s light and p light of the incident light relative to the incident surface of the mirror after passing through the reflective polarization rotation unit is 180°, and the reflective polarization rotation unit includes four mirrors, and the phase delay amount of the mutually perpendicular s light and p light of the incident light relative to the incident surface of the mirror after passing through each of the mirrors includes but is not limited to: the phase delay amount of three mirrors is 0°, and the phase delay amount of the other mirror is 180°; or, the phase delay amount of two mirrors is 0°, and the phase delay amount of the other two mirrors is 90°. Wherein, when the phase delay amount of the mirror passed through is 0°, the phase delay amount of the mutually perpendicular s light and p light of the incident light relative to the incident surface of the mirror is the same; when the phase delay amount of the mirror passed through is not 0°, the phase delay amount of the mutually perpendicular s light and p light of the incident light relative to the incident surface of the mirror is different.

[0048] And, when the reflective polarization rotation unit includes at least three mirrors, the direction of the output light is coaxial with the direction of the incident light.

[0049] In addition, the back surface of the mirror can be provided with a cooling water flow channel connected with a water cooling device to cool the mirror when high-power incident light is incident on the mirror, so that the temperature variation of the mirror is small.

[0050] Preferably, all the mirrors can be arranged on the same base plate, and a load is arranged above the reflective polarization rotation unit to ensure that the center of gravity of the reflective polarization rotation unit is on the optical axis of the incident light.

[0051] The laser power tuning and attenuation device can further include a rotating unit and a braking unit, wherein the rotating unit drives the reflective polarization rotation unit to rotate around the optical axis of the incident light in the range of 0°-360°, and the braking unit locks the reflective polarization rotation unit rotated to a predetermined angle. Wherein, the rotating unit is, for example, a motor, and the braking unit is, for example, a band brake device.

[0052] In addition, the power of the output light can be detected by a detection unit in the annealing equipment. The detection unit is, for example, a power meter. Wherein, according to the power of the output light detected by the detection unit, the rotation angle of the reflective polarization rotation unit around the optical axis of the incident light can be adjusted through a specific algorithm, that is, a feedback adjustment mechanism is introduced, so that the power of the output light after adjustment can meet the requirements of the annealing process.

[0053] The polarizing beam splitter is capable of reflecting light with a specific polarization state (s-ray or p-ray). After passing through the reflective polarization rotation unit, both s-ray and p-ray reach the polarizing beam splitter. If the polarizing beam splitter reflects s-ray, the detection unit detects s-ray, while p-ray is absorbed or transmitted by the polarizing beam splitter. If the polarizing beam splitter reflects p-ray, the detection unit detects p-ray, while s-ray is absorbed or transmitted by the polarizing beam splitter.

[0054] exist Figure 1 In the illustrated embodiment, laser 11 emits high-power incident light, which is reflected sequentially by the first reflector 121, the second reflector 122, the third reflector 123, and the fourth reflector 124 to form outgoing light. The incident surfaces of the first reflector 121, the second reflector 122, the third reflector 123, and the fourth reflector 124 are located on the same plane. The sum of the phase delays of the mutually perpendicular s-rays and p-rays of the incident light relative to the incident surfaces of the four reflectors is an odd multiple of 180°. The outgoing light is reflected by the polarizing beam splitter 13 to obtain output light with reduced power. The power meter 14 receives the output light and detects its power.

[0055] Will Figure 1 After the reflective polarization rotation unit (i.e., four mirrors) in the laser power tuning attenuation device shown rotates around the optical axis of the incident light, as... Figure 2 As shown, when the polarization direction E of the incident light 入射 Along the x-axis, the reflective polarization rotation unit is rotated so that the incident surface is aligned with the polarization direction E of the incident light. 入射 When the angle between the two axes (i.e., the x-axis direction) is θ, the polarization direction E of the emitted light is... 出射 The polarization direction E of the incident light is changed. 入射 The angle between (i.e., the x-axis direction) and (i.e., the polarization direction E of the emitted light) is 2θ. 出射 Relative to the polarization direction E of the incident light 入射 If the rotation angle is 2θ, then the optical power I of the polarization state in the x-axis direction (i.e., p-light) is... p =I in *cos 2 (2θ), the optical power I of the polarization state in the y-axis direction (i.e., s-light). s =I in *sin 2 (2θ), where I in The power of the incident light; the outgoing light strikes the polarizing beam-splitting mirror 13, causing s-rays or p-rays with a specific polarization state to be reflected. Figure 2The s-polarized light is reflected, and the polarization direction E 反射 The reflected light is detected by the power meter 14 as output light along the y-axis direction. It should be noted that the s-polarized light of the incident light and the output light refers to the light with a polarization direction perpendicular to the incident plane of the polarization beam splitter 13, the p-polarized light of the incident light and the output light refers to the light with a polarization direction parallel to the incident plane of the polarization beam splitter 13, and the s-polarized light and the p-polarized light in the phase delay of the reflective polarization rotation unit correspond to the light with a polarization direction perpendicular to and parallel to the incident plane of the reflective polarization rotation unit, respectively.

[0056] According to the calculation formula of the p-polarized light power I p and the s-polarized light power I s , as the reflective polarization rotation unit is rotated around the optical axis of the incident light to change the angle θ between the incident plane and the polarization direction E 入射 of the incident light, the proportion of the s-polarized light and the p-polarized light of the output light changes, and then the polarization beam splitter reflects the s-polarized light or the p-polarized light, so as to realize the tunable attenuation of the output light power.

[0057] Taking the s-polarized light as an example, referring to Figure 3 and Figure 4 , it can be seen from Figure 3 and Figure 4 that as the angle (i.e. θ) between the incident plane of the mirror and the polarization direction of the incident light changes, the p-polarized light power and the s-polarized light power of the output light change constantly, which indicates that the proportion of the s-polarized light and the p-polarized light of the output light can be changed by rotating the reflective polarization rotation unit around the optical axis of the incident light.

[0058] Referring to Figures 5a to 5d , the optical simulation software is used to simulate the spot of the incident light, the x-axis direction is the polarization direction of the incident light, and the direction of the straight line is the polarization direction of the output light. In Figure 5a , the polarization direction of the output light is the same as the polarization direction of the incident light. It can be seen from Figures 5b to 5d that when the reflective polarization rotation unit is rotated to the angles between the incident plane and the polarization direction of the incident light are 10°, 30° and 45° respectively, the corresponding simulated rotation angles of the polarization direction of the output light relative to the polarization direction of the incident light are 20° Figure 5b , 60° Figure 5c and 90° Figure 5d respectively, which verifies that the rotation angle of the polarization direction of the output light relative to the polarization direction of the incident light is twice the angle between the incident plane and the polarization direction of the incident light when the reflective polarization rotation unit is rotated.

[0059] Referring to Figure 6 , the incident light emitted by the light source in the test bench is linearly polarized light with an angle of 45° with the x-axis, the incident light contains s light and p light with a power ratio of 1:1, and the polarizing beam splitter has a high reflectivity to s light. As can be seen from the comparison chart of the measured data of the test bench and the theoretical calculation value, when the angle between the incident surface of the mirror and the polarization direction of the incident light is 0°, the polarization direction of the outgoing light is unchanged (that is, the rotation angle of the polarization direction of the outgoing light relative to the polarization direction of the incident light is 0°), so the power of the s light reflected by the polarizing beam splitter is half of the total power of the incident light; when the angle between the incident surface of the mirror and the polarization direction of the incident light is 22.5°, the 45° linearly polarized light is completely converted into s light in the vertical direction (that is, 22.5°*2+45°=90°), so the power of the s light reflected by the polarizing beam splitter is close to 100% of the total power of the incident light; when the angle between the incident surface of the mirror and the polarization direction of the incident light is -22.5°, the 45° linearly polarized light is completely converted into p light in the horizontal direction (that is, -22.5°*2+45°=0°), so the power of the s light reflected by the polarizing beam splitter is close to 0. Therefore, by comparing the measured data with the theoretical calculation value, the theoretical correctness and feasibility of the scheme of the present application are verified.

[0060] In addition, in the embodiment shown in Figure 7 , the reflective polarization rotation unit in the laser power tuning and attenuation device includes five mirrors, i.e., a first mirror 121, a second mirror 122, a third mirror 123, a fourth mirror 124, and a fifth mirror 125; in the embodiment shown in Figure 8 , the reflective polarization rotation unit in the laser power tuning and attenuation device includes six mirrors, i.e., a first mirror 121, a second mirror 122, a third mirror 123, a fourth mirror 124, a fifth mirror 125, and a sixth mirror 126. In the embodiments shown in Figure 1 , Figure 7 , and Figure 8 , by adjusting the relative positions and angles between the mirrors, the reflective polarization rotation unit achieves the corresponding functions. Moreover, compared with the embodiment shown in Figure 1 , the embodiments shown in Figure 7 , and Figure 8 include more mirrors in the reflective polarization rotation unit, so that the selectivity of the optical path space adjustment and the mirror phase delay amount processing requirement is greater, and the flexibility is greater.

[0061] The steps of realizing laser power tuning attenuation by using the laser power tuning attenuation device include: first, turning on the laser, which emits high-power mid-infrared incident light; then, calculating and adjusting the rotation angle of the reflective polarization rotation unit around the optical axis of the incident light according to the power requirement of the annealing process; then, adjusting the rotation angle of the reflective polarization rotation unit according to the power of the output light reflected by the polarization beam splitter detected by the detection unit; then, locking the position of the adjusted reflective polarization rotation unit by using the brake unit, and continuing the subsequent annealing process.

[0062] From the above, by using the laser power tuning attenuation device to tune and attenuate the laser power, the external power tuning is used to replace the power tuning of the laser itself in the laser annealing equipment, so that the stability of the size and directivity of the output light can be maintained, and the annealing process index (for example, the uniformity of annealing) is improved; and the full mirror system composed of the reflective polarization rotation unit and the polarization beam splitter is used to replace the lens system composed of the traditional half-wave plate and the polarization beam splitter, so that the polarization direction of the light emitted after the reflective polarization rotation unit is rotated by a certain angle relative to the polarization direction of the incident light, so that the power damage threshold of the component can be improved, the output light power can be effectively tuned, the laser power attenuation in the high-power laser annealing equipment can be accurately controlled, and the demand of the high-power mid-infrared laser annealing equipment is met.

[0063] In addition, the reflective polarization rotation unit requires less rotation space, does not need large-aperture lenses and large-angle incidence, and has simpler requirements for electromechanical control.

[0064] An embodiment of the present application provides an annealing equipment, which comprises a laser and the laser power tuning attenuation device, the laser emits laser as incident light, the laser power is tuned and attenuated by the laser power tuning attenuation device to obtain output light, and the annealing process is performed on the workpiece to be annealed by using the output light, so that the stability of the size and directivity of the output light can be maintained while the output light power is effectively tuned, thereby improving the annealing process index and meeting the demand of the high-power mid-infrared laser annealing equipment.

[0065] In addition, the annealing equipment further comprises a detection unit, which is used to detect the power of the output light and adjust the rotation angle of the reflective polarization rotation unit according to the detection result. Since the annealing equipment further comprises the detection unit, the feedback adjustment mechanism is introduced, so that the angle of the reflective polarization rotation unit rotating around the optical axis of the incident light can be accurately controlled, and the output light power can be accurately controlled.

[0066] The above description is only the description of the preferred embodiments of the present application, and is not any limitation on the scope of the present application. Any change and modification made by the person skilled in the art according to the above disclosure is within the protection scope of the claims.

Claims

1. A laser power tuning and attenuation device, characterized by, The laser power tuning attenuation device comprises a reflective polarization rotation unit and a polarization beam splitter, the reflective polarization rotation unit comprises at least two mirrors, and the incidence planes of all the mirrors are located in the same plane; the reflective polarization rotation unit is used for receiving incident light, the reflective polarization rotation unit is rotatably arranged around the optical axis of the incident light, the phase delay amount of the mutually perpendicular s light and p light of the incident light relative to the incidence plane after passing through the reflective polarization rotation unit is an odd multiple of 180°, so that the polarization direction of the outgoing light after passing through the reflective polarization rotation unit is rotated by a certain angle relative to the polarization direction of the incident light, and the outgoing light is reflected by the polarization beam splitter to obtain output light with power attenuation; when the reflective polarization rotation unit is rotated to the angle between the incidence plane and the polarization direction of the incident light is θ, the polarization direction of the outgoing light is rotated by an angle of 2θ relative to the polarization direction of the incident light.

2. The laser power tuning and attenuation device of claim 1, wherein, The base of the mirror and the base of the polarization beam splitter are both high-power-resistant materials, and both resist a power greater than or equal to 500W per square centimeter.

3. The laser power tuning and attenuation device of claim 2, wherein, The base of the mirror comprises Cu or Au.

4. The laser power tuning and attenuation device of claim 2, wherein, The base of the polarization beam splitter comprises at least one of Cu, ZnSe, BaF2 and CaF2.

5. The laser power tuning and attenuation device of claim 1, wherein, The surface of the mirror is coated with at least one film to cause the mutually perpendicular s light and p light of the incident light relative to the incidence plane to have a phase delay amount.

6. The laser power tuning and attenuation device of claim 5, wherein, The film is a single-layer structure or a structure of at least two layers stacked, and the material of each layer structure comprises at least one of ZnSe, Ge and a fluorine compound.

7. The laser power tuning and attenuation device of claim 1, wherein, The reflective polarization rotation unit comprises at least three mirrors, and the direction of the outgoing light is coaxial with the direction of the incident light.

8. The laser power tuning and attenuation device of claim 1, wherein, The back of the mirror is provided with a cooling water flow channel.

9. The laser power tuning and attenuation device of claim 1, wherein, All the mirrors are arranged on the same base plate, and the center of gravity of the reflective polarization rotation unit is on the optical axis of the incident light.

10. The laser power tuning and attenuation device of claim 1, wherein, The laser power tuning attenuation device further comprises a rotation unit and a brake unit, the rotation unit drives the reflective polarization rotation unit to rotate around the optical axis of the incident light, and the brake unit locks the reflective polarization rotation unit rotated to a predetermined angle.

11. An annealing apparatus characterized by comprising: The laser power tuning attenuation device comprises a laser and a laser power tuning attenuation device as claimed in any one of claims 1-10, and the incident light emitted by the laser is subjected to power-tunable attenuation by the laser power tuning attenuation device.

12. The annealing apparatus of claim 11, wherein, The annealing device further comprises a detection unit for detecting the power of the output light and adjusting the rotation angle of the reflective polarization rotation unit according to the detection result.

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