A method, device and equipment for cooperative control of a laser beam line multi-mirror

Abstract

This application provides a collaborative control method, apparatus, and device for multiple reflectors in a laser beamline, relating to the field of electronic laser technology. The method includes: a laser beamline multiple reflector comprising multiple reflectors; acquiring attribute parameters of the currently compensated mirror and the upstream reflector among the multiple reflectors; wherein the upstream reflector of the compensated mirror includes an active thermal compensation component; and controlling the active thermal compensation component to compensate the compensated mirror based on the attribute parameters of the compensated mirror and the upstream reflector. This application achieves compensation for the downstream compensated mirror by controlling the active thermal compensation component integrated into the upstream reflector, thereby using the active compensation capability of the upstream reflector to correct the thermal deformation of the downstream reflector. This overcomes the limitations of traditional one-to-one independent control, effectively offsetting the accumulated thermal surface shape error in the beam transmission path and significantly improving the overall beam quality.

Description

Technical Field

[0001] This application relates to the field of electronic laser technology, and more specifically, to a method, apparatus, and device for the coordinated control of multiple reflectors in a laser beamline. Background Technology

[0002] With the development of high-repetition-rate free-electron laser technology, the mirrors in the beamline face severe thermal load problems. After absorbing high-energy photons, the optical components will undergo thermal deformation, resulting in distortion of the reflective surface, which in turn reduces the beam quality transmitted to the experimental station.

[0003] To control thermal deformation, existing technologies have developed passive cooling (such as optimizing cooling channels) and active surface shape control (such as piezoelectric crystals, active thermal compensation, and mechanical bending). However, these technologies are limited to controlling the surface shape of each individual mirror independently by adding a control component to each mirror on a one-to-one basis. They cannot utilize the surface shape error of the upstream mirror to offset the thermal deformation of the downstream mirror, resulting in poor overall beam quality. Summary of the Invention

[0004] The purpose of this application is to provide a method, apparatus, and device for the coordinated control of multiple reflectors in a laser beamline, which solves the above-mentioned problems in the prior art. By controlling the active thermal compensation component built into the upstream reflector, compensation can be achieved for the downstream compensated mirror, thereby significantly improving the overall beam quality.

[0005] In a first aspect, a method for the coordinated control of multiple laser beamline reflectors is provided, wherein the laser beamline reflectors include multiple reflectors, and the method may include: The attribute parameters of the current compensated mirror and the upstream mirror of the compensated mirror are obtained from multiple mirrors respectively; wherein the upstream mirror of the compensated mirror includes an active thermal compensation component. The active thermal compensation component is controlled to compensate the compensated mirror based on the property parameters of the compensated mirror and the upstream reflector.

[0006] In an optional implementation, the active thermal compensation component is controlled to compensate the compensated mirror based on the property parameters of the compensated mirror and the upstream reflector, including: Based on the property parameters of the compensated mirror and the upstream reflector, the target surface shape to be compensated is determined. Based on the target surface shape to be compensated, the attribute parameters of the compensated mirror and the upstream reflector of the compensated mirror, the target power of the active thermal compensation component is determined. Based on the target power, the property parameters of the upstream reflector of the compensated mirror, and the property parameters of the compensated mirror, the active thermal compensation component is used to compensate the compensated mirror.

[0007] In an optional implementation, the properties of the upstream mirror of the compensated mirror include: grazing angle and initial thermal profile; the properties of the compensated mirror include: grazing angle, initial thermal profile, material elastic modulus, and moment of inertia.

[0008] In an optional implementation, the target surface shape to be compensated is determined based on the property parameters of the compensated mirror and the upstream reflector, including: Based on the grazing angles of the compensated mirror and the upstream reflector, the initial thermal surface shape of the compensated mirror is mapped onto the reflector, and surface shape decoupling processing is performed to obtain the target surface shape.

[0009] In an optional implementation, the target power of the active thermal compensation component is determined based on the target surface shape to be compensated, the attribute parameters of the compensated mirror and the upstream reflector of the compensated mirror, including: Based on the pre-constructed power-surface coupling model, the initial thermal surface shape and grazing angle of the compensated mirror and the upstream reflector of the compensated mirror, the target power of the active thermal compensation component corresponding to the target surface shape is determined with the target surface shape as the optimization target.

[0010] In an optional implementation, the active thermal compensation component compensates the compensated mirror based on the target power, the property parameters of the upstream reflector and the property parameters of the compensated mirror, including: The active thermal compensation component is controlled to heat the upstream mirror of the compensated mirror with the target power, so that the upstream mirror of the compensated mirror produces a target compensation surface shape with the opposite direction to the target surface shape; Based on the grazing angles of the compensated mirror and the upstream reflector, the target compensation surface shape is mapped onto the compensated mirror and superimposed with the initial thermal surface shape of the compensated mirror to compensate the compensated mirror.

[0011] In an optional implementation, the compensated mirror includes a mechanical bending assembly; the attribute parameters of the compensated mirror further include the lever arm of the mechanical bending assembly. After mapping the target compensation surface shape onto the compensated mirror and superimposing it with the initial thermal surface shape of the compensated mirror, the method further includes: The surface shape of the compensated mirror after superimposing the target compensation surface shape is taken as the comprehensive surface shape; Determine the curved surface shape in the composite surface shape; Based on the bending surface shape, the elastic modulus of the material of the compensated mirror, the moment of inertia of the section, and the lever arm, the target bending parameters of the mechanical bending assembly are determined. The mechanical bending assembly is controlled to bend the compensated mirror with the target bending parameters, so that the compensated mirror produces a compensation surface shape that is opposite to the direction of the bending surface shape, thereby completing the compensation of the compensated mirror.

[0012] Secondly, a collaborative control device for a laser beamline multi-reflector is provided, wherein the laser beamline multi-reflector includes multiple reflectors, and the device may include: The acquisition unit is used to acquire the attribute parameters of the current compensated mirror and the upstream mirror of the compensated mirror among a plurality of mirrors; wherein the upstream mirror of the compensated mirror includes an active thermal compensation component. The compensation unit is used to control the active thermal compensation component to compensate the compensated mirror based on the attribute parameters of the compensated mirror and the upstream reflector of the compensated mirror.

[0013] Thirdly, an electronic device is provided, which includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; When a processor executes a program stored in memory, it implements any of the steps described in the first aspect above.

[0014] Fourthly, a computer-readable storage medium is provided, wherein a computer program is stored therein, and when executed by a processor, the computer program implements the steps of any of the methods described in the first aspect above.

[0015] This application obtains the attribute parameters of the compensated mirror and its upstream mirror respectively, and controls the active thermal compensation component built into the upstream mirror based on these parameters to achieve compensation for the downstream compensated mirror. In this way, the active compensation capability of the upstream mirror is used to correct the thermal deformation of the downstream mirror, which breaks through the limitations of traditional one-to-one independent control. By utilizing the parameter coordination of the two mirrors, the accumulated thermal surface shape error in the beam transmission path is effectively offset, and the overall beam quality is significantly improved. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 An architecture diagram of a collaborative control system for multiple laser beam mirrors provided in an embodiment of this application; Figure 2 A flowchart illustrating a collaborative control method for multiple laser beam mirrors provided in an embodiment of this application; Figure 3 A schematic diagram illustrating the collaborative control principle of multiple reflectors in a laser beamline, provided in an embodiment of this application; Figure 4 A schematic diagram of a side-mounted plane mirror and its corresponding cooling device and active thermal compensation device provided in an embodiment of this application; Figure 5 A schematic diagram of a side-mounted pressure bending mirror and a corresponding cooling device provided in an embodiment of this application; Figure 6 A schematic diagram of the meridional surface shape of the spot area before compensation by each reflector and the surface shape effect after superposition, provided in an embodiment of this application; Figure 7 A schematic diagram of the output power of each electric heating element in an active thermal compensation component for a plane mirror provided in this application embodiment; Figure 8 A schematic diagram of the meridional surface shape of the light spot area after compensation by each reflector and the surface shape effect after superposition, provided in an embodiment of this application; Figure 9 A schematic diagram of the optical tracing effect of a focused spot in the X direction provided in an embodiment of this application; Figure 10 A schematic diagram of a flat plane mirror and its corresponding cooling device and active thermal compensation device provided in the embodiments of this application; Figure 11 A schematic diagram of a flat-lay bending mirror and a corresponding cooling device provided in an embodiment of this application; Figure 12 A schematic diagram of the meridional surface shape of the spot area before compensation by each reflector and the surface shape effect after superposition, provided for an embodiment of this application; Figure 13 A schematic diagram of the output power of each electric heating element in another plane mirror active thermal compensation component provided in this application embodiment; Figure 14 A schematic diagram of the meridional surface shape of the spot area after compensation by each reflector and the superimposed surface shape effect provided in an embodiment of this application; Figure 15 A schematic diagram of the optical tracing effect of a focused spot in the Y direction provided in an embodiment of this application; Figure 16 A schematic diagram of the structure of a collaborative control device for multiple laser beam mirrors provided in an embodiment of this application; Figure 17 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application; In the diagram: 100, side-mounted plane mirror; 200, electric heating element; 300, light spot of side-mounted plane mirror; 400, side-mounted bending mirror; 500, light spot of side-mounted bending mirror; 600, flat-mounted plane mirror; 700, light spot of flat-mounted plane mirror; 800, flat-mounted bending mirror; 900, light spot of flat-mounted bending mirror. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise defined, the technical or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art. The words "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are only used to distinguish different components. The words "comprising" or "including," etc., mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but do not exclude other elements or objects. The words "connected," "coupled," or "connected," etc., are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up," "down," "left," "right," etc., are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0019] The collaborative control method for multiple reflectors in a laser beamline provided in this application embodiment can be applied to, for example... Figure 1 In the system architecture shown, such as Figure 1 As shown, the system may include: a server, a data acquisition component, and an active thermal compensation component; the active thermal compensation component is mounted on a reflector upstream of the compensated mirror. Among them, the data acquisition component is used to acquire the attribute parameters of the current compensated mirror and the upstream mirror of the compensated mirror in multiple mirrors respectively; The server is used to execute the collaborative control method for multiple laser beamline reflectors provided in this application embodiment. Based on the attribute parameters of the compensated mirror and the upstream reflector, it controls the active thermal compensation component to compensate the compensated mirror. The server can be a physical server, a server cluster composed of multiple physical servers, or a distributed system. It can also be a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms. The server can be directly or indirectly connected to the data acquisition component and the active thermal compensation component via wired or wireless communication methods; this application does not impose any limitations on this connection.

[0020] In one embodiment of this application, the active thermal compensation component may include: a plurality of electric heating elements and a heating controller connected to the plurality of electric heating elements; the plurality of electric heating elements are attached to the surface of the cooling block of the reflector upstream of the compensated mirror or the back of the mirror body to provide controllable heat input; the heating controller is electrically connected to each electric heating element and is used to adjust the current or voltage of each heating element according to the target power sent by the server.

[0021] In another embodiment of this application, the system may further include: a mechanical bending assembly disposed on the compensated mirror; the mechanical bending assembly may include: a bending actuator, a force / displacement transmission mechanism, a support structure, and a bending controller; wherein, the bending actuator may be a motor-driven lead screw, a worm gear, or a hydraulic / pneumatic actuator, installed at both ends of the bending mirror, for applying bending moment; the force / displacement transmission mechanism may be a lever, a spring plate, or an elastic hinge, for converting the linear motion or force of the actuator into pure bending moment at both ends of the mirror; the support structure may be a mirror frame with flexible hinges, enabling the bending mirror to undergo controllable cylindrical bending while avoiding additional torsion or distortion; the bending controller is electrically connected to the bending actuator, for controlling the output force or displacement according to the target bending parameters sent by the server.

[0022] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application. Furthermore, the embodiments and features in the embodiments of this application can be combined with each other without conflict.

[0023] Figure 2 This is a flowchart illustrating a collaborative control method for multiple reflectors in a laser beamline, provided as an embodiment of this application. Figure 1 As shown, the method may include: Step S210: Obtain the attribute parameters of the current compensated mirror and the upstream mirror of the compensated mirror among the multiple mirrors.

[0024] The properties of the upstream reflector of the compensated mirror may include: grazing angle and initial thermal profile; the properties of the compensated mirror include: grazing angle, initial thermal profile, material elastic modulus, moment of inertia of section, and lever arm of the mechanical bending assembly on the compensated mirror; the compensating mirror can be a bending mirror; the upstream reflector of the compensated mirror can be a plane mirror; the upstream reflector of the compensated mirror is used as the compensating mirror; the plane mirror is equipped with an active thermal compensation assembly; the compensated mirror is equipped with a mechanical bending assembly; the initial thermal profile is a spatial distribution function used to describe the height error at each position along the length direction (meridian) of the reflector spot, and the initial profile includes the abscissa of different points within the spot area of ​​the corresponding reflector and the corresponding height error value.

[0025] In practice, the grazing angles of the compensating mirror and the upstream mirror of the compensated mirror can be collected from the optical design parameters of the laser beam. These grazing angles are determined by the beam deflection angle and the mirror mounting posture. The initial thermal surface shape can be obtained by measuring the surface morphology of the mirror using a long-range profilometer (LTP), interferometer, or optical profilometer after the thermal load has stabilized. Alternatively, a thermal-structural coupling model of the mirror body and cooling structure can be established using finite element analysis (FEA) software (such as ANSYS or COMSOL), and the beam power density distribution and cooling boundary conditions can be applied to calculate the thermal deformation distribution and obtain the initial thermal surface shape.

[0026] Step S220: Based on the attribute parameters of the compensated mirror and the upstream reflector, control the active thermal compensation component to compensate the compensated mirror.

[0027] In practice, the target surface shape to be compensated is determined based on the attribute parameters of the compensated mirror and the upstream reflector. Specifically, according to the grazing angle of the compensated mirror and the upstream reflector, the initial thermal surface shape of the compensated mirror is mapped onto the reflector, and surface shape decoupling processing is performed to obtain the target surface shape. Surface shape decoupling processing includes normalization processing and curvature removal processing. Curvature removal processing is to subtract the bending component of the quadratic fitting. Based on the target surface shape to be compensated, the attribute parameters of the compensated mirror and the upstream reflector of the compensated mirror, the target power of the active thermal compensation component is determined; specifically, based on the pre-built power-surface shape coupling model, the initial thermal surface shape of the compensated mirror and the upstream reflector of the compensated mirror, the target surface shape is used as the optimization target to determine the target power of the active thermal compensation component corresponding to the target surface shape. Based on the target power, the property parameters of the upstream reflector of the compensated mirror, and the property parameters of the compensated mirror itself, an active thermal compensation component is used to compensate the compensated mirror. Specifically, the active thermal compensation component is controlled to heat the upstream reflector of the compensated mirror at the target power, so that the upstream reflector of the compensated mirror produces a target compensation surface shape with the opposite direction to the target surface shape. Here, the target surface shape and the target compensation surface shape are opposite in direction because they have the same shape but opposite concavity and convexity. According to the target power, the heating controller of the active thermal compensation component is controlled to output the corresponding current or voltage to control each heating element of the active thermal compensation component to heat up according to the target power, so that the compensated mirror produces the actual surface shape under the combined action of thermal load and active heating. The actual surface shape may include: the initial thermal surface shape of the compensated mirror itself and the thermal deformation caused by heating. Based on the grazing angles of the compensated mirror and the upstream reflector, the target compensation surface shape is mapped onto the compensated mirror and superimposed with the initial thermal surface shape of the compensated mirror to obtain the composite surface shape. Specifically, based on the divergence angle of the configured laser beam, it is determined whether the incident beam of the laser beam is parallel. If the incident beam is parallel, the spot length ratio is calculated based on the grazing angles of the compensated mirror and the upstream reflector. If the incident beam is non-parallel, the spot length ratio is calculated based on the geometric parameters of the configured laser beam, the grazing angle of the compensated mirror, and the upstream reflector. Based on the spot length ratio, the target compensation surface shape is scaled and mapped onto the spot area of ​​the compensated mirror to obtain a third scaled surface shape. The third scaled surface shape is linearly superimposed with the initial thermal surface shape of the compensated mirror to obtain the composite surface shape. Determine the curved surface shape in the composite surface shape; wherein, the composite surface shape is fitted with a quadratic polynomial or the equivalent curvature is calculated directly along the light spot length direction, and the curved surface shape, i.e. the quadratic term part, is also the overall curved component; Based on the curved surface shape, the elastic modulus and moment of inertia of the material of the compensated mirror, and the lever arm of the mechanical bending assembly on the compensated mirror, the target bending parameters of the mechanical bending assembly are determined. Specifically, based on the curved surface shape, the equivalent curvature corresponding to the curved surface shape is determined. The target bending parameters are calculated based on the lever arm, the elastic modulus of the material, the moment of inertia of the section, and the equivalent curvature corresponding to the curved surface shape. The calculation formula for the target bending parameters is as follows: ; d represents the target bending parameter; d represents the lever arm of the mechanical bending component on the compensated mirror; E represents the elastic modulus of the compensated mirror material; I represents the moment of inertia of the compensated mirror section. This represents the compressive bending rate. The equivalent curvature produced when the surface shape is corrected by compressive bending should be opposite to it to counteract the surface shape. That is, the compressive bending rate satisfies: ; This represents the equivalent curvature corresponding to the curved surface shape; The mechanical bending assembly is controlled to bend the compensated mirror with target bending parameters, so that the compensated mirror produces a compensation surface shape opposite to the direction of the bending surface shape, thereby completing the compensation of the compensated mirror. Specifically, the mechanical bending assembly is controlled to apply a reverse bending moment to the compensated mirror (i.e., the bending mirror) with the target bending parameters, so that the bending mirror produces a cylindrical bend opposite to the direction of the bending surface shape. The curvature of this cylindrical bend is equal in magnitude but opposite in sign to the curvature of the bending surface shape, thereby canceling the bending surface shape on the bending mirror. After the bending surface shape is canceled, the remaining residual surface shape on the bending mirror (mainly including incompletely eliminated higher-order residuals and measurement noise) is the final compensation surface shape, thus completing the compensation of the compensated mirror.

[0028] In one embodiment of this application, based on the grazing angles of the compensated mirror and the upstream reflector, the initial thermal surface shape of the compensated mirror is mapped onto the reflector, and surface shape decoupling processing is performed to obtain the target surface shape, including: Based on the divergence angle of the configured laser beam, determine whether the incident beam of the laser beam is parallel light; If the incident laser beam is parallel, the spot length ratio is calculated based on the grazing angle of the compensated mirror and the grazing angle of the upstream mirror. The formula for calculating the spot length ratio is as follows: ;in, This indicates the glancing angle of the mirror upstream of the compensated mirror; Indicates the glancing angle of the compensated mirror; Indicates the ratio of light spot length; If the incident beam of the laser beamline is non-parallel, the spot length ratio is calculated based on the configured geometric parameters of the laser beamline, the grazing angle of the compensated mirror, and the grazing angle of the upstream reflector of the compensated mirror. The geometric parameters of the laser beamline may include: a first distance from the source point of the laser beamline to the upstream reflector of the compensated mirror, and a second distance from the upstream reflector of the compensated mirror to the compensated mirror. The formula for calculating the spot length ratio is: ; Indicates the second distance; Indicates the first distance; The initial thermal surface shape of the compensated mirror is scaled using the spot length ratio to obtain the first scaled surface shape. Specifically, the horizontal coordinates and corresponding height errors of different positions of the compensated mirror are scaled using the spot length ratio to obtain the mapped surface shape of the initial thermal surface shape of the compensated mirror on the spot area of ​​the upstream mirror. The first scaled surface shape is the scaled surface shape mapped onto the spot area of ​​the compensated mirror. The first scaled surface shape undergoes surface shape decoupling processing to obtain the target surface shape. The target surface shape characterizes the distribution of non-quadratic terms (i.e., local distortion components) in the initial thermal surface shape of the compensated mirror that cannot be eliminated by mechanical bending, mapped onto the compensating mirror spot area after geometric scaling. The target surface shape corresponds to the higher-order error pattern that needs to be offset by reverse deformation generated by the active thermal compensation component of the compensating mirror. Specifically, the first scaled surface shape is normalized to obtain the second scaled surface shape. The abscissas of different points in the first scaled surface shape are linearly mapped to a configured standard... The interval is used to obtain the abscissas of different positions. The abscissas of different positions and the height errors of different positions in the first scaled surface are used as the second scaled surface. The second scaled surface is decurvatured to obtain the target surface. The target surface is the higher-order surface. The height errors of different positions in the second scaled surface are fitted with a quadratic polynomial to obtain the fitted curvature surface. The residuals are calculated based on the second scaled surface and the fitted curvature surface to obtain the higher-order surface, i.e., the target surface. The difference between the second scaled surface and the fitted curvature surface is used as the residual.

[0029] In another embodiment of this application, based on a pre-built power-surface coupling model, the initial thermal surface shape and grazing angle of the compensated mirror and the upstream reflector of the compensated mirror, the target power of the active thermal compensation component corresponding to the target surface shape is determined with the target surface shape as the optimization target, including: Based on the divergence angle of the configured laser beam, determine whether the incident beam of the laser beam is parallel. If the incident beam of the laser beam is parallel, calculate the spot length ratio based on the grazing angle of the compensated mirror and the grazing angle of the upstream reflector. If the incident beam of the laser beam is non-parallel, calculate the spot length ratio based on the geometric parameters of the configured laser beam, the grazing angle of the compensated mirror, and the grazing angle of the upstream reflector. Based on the initial thermal surface shape of the compensated mirror and the initial thermal surface shape of the upstream reflector, a first higher-order residual surface shape and a second higher-order residual surface shape are calculated respectively. Specifically, the first residual surface shape is obtained by removing the fitted curvature surface shape from the initial thermal surface shape of the upstream reflector; this residual surface shape is a curve; the curve average value of the first residual surface shape is calculated to obtain the first surface shape average value; the first higher-order residual surface shape is obtained by subtracting the first surface shape average value from the first residual surface shape; the second residual surface shape is obtained by removing the fitted curvature surface shape from the initial thermal surface shape of the compensated mirror; the curve average value of the second residual surface shape is calculated to obtain the second surface shape average value; the second higher-order residual surface shape is obtained by subtracting the second surface shape average value from the second residual surface shape. The target surface shape, the first higher-order residual surface shape, the second higher-order residual surface shape, the spot length ratio, and the pre-constructed power-surface shape coupling model are input into the pre-constructed objective equation for the target power. Using the target surface shape as the optimization objective, the objective equation for the target power is solved using the least squares method to obtain the target power of the active thermal compensation component corresponding to the target surface shape. Specifically, the objective equation for the target power is as follows: ;in, The power-surface coupling model represents the relationship between the target surface shape of the superimposed mirror located upstream of the compensated mirror and the target power of the active thermal compensation component. The power-surface coupling model is established by applying unit power to each electric heating element in the active thermal compensation component and measuring the response surface shape, and is used to characterize the mapping relationship between heating power and the generated surface shape; S(x) represents the response function matrix of the active thermal compensation component, which is an m×n matrix, where m is the number of response surface shape sampling points and n is the number of electric heating elements in the active thermal compensation component. The response curves are obtained by first applying unit power to each electric heating element in the active thermal compensation component in sequence, and then subtracting the average value of each curve to obtain the response function of each heating element, which is finally integrated into S(x); T(x) represents the target surface shape, which is approximately a straight line with a magnitude of 0; Represents the first higher-order residual surface shape; This represents the second higher-order residual surface shape.

[0030] In practical calculations, based on the above objective equation, an approximate formula for calculating the target power can be derived as follows: ; Using the target surface shape as the optimization objective, the least squares method is used to solve the approximate calculation formula for the target power, thereby obtaining the target power of the active thermal compensation component corresponding to the target surface shape.

[0031] In another embodiment of this application, after obtaining the compensation surface shape of the compensated mirror, the method further includes: Based on the spatial distribution of each mirror and parameters such as the position of the light source, the divergence angle of the light source, and the direction of beam propagation, an optical path is constructed in optical tracing software such as Shadow. The surface shape after compensation of the plane mirror and the thermal surface shape of the bent mirror are input to simulate the parameters such as the full width at half maximum (FWHM), peak intensity, etc. of the focused spot, and the beam quality is verified.

[0032] In practical applications, such as Figure 3As shown, the light beam from the light source propagates to the optical surface of the plane mirror at point D1, producing a light spot of length a. The plane mirror is used as the compensating mirror, and an active thermal compensation component is added. The light beam reflected from the plane mirror continues to propagate to the optical surface of the bending mirror at point D2, producing a light spot of length b. The thermal surface shape of this light spot needs further compensation for its higher-order components. The bending mirror is used as the compensated mirror, and a mechanical bending component is added. The grazing angle of the compensating mirror is θ1, and the grazing angle of the compensated mirror is θ2. If D2 is significantly smaller than D1, the ratio of the coverage lengths of the light spots on the two mirrors can be approximately calculated as b:a = sinθ1 / sinθ2. From the perspective of optical path difference, if a microbeam is irradiated at point A of the compensating mirror, and the height error of the deformation at point A relative to the reference plane is ΔH1, then an optical path difference of ΔH1sinθ1 will be generated at that point. To eliminate the optical path difference, a surface shape needs to be constructed at point B on the compensated mirror where the microbeam is illuminating. This surface shape compensates for the optical path difference. The height error corresponding to point B on the compensated mirror should be calculated as ΔH2 = ΔH1sinθ1 / sinθ2 = ΔH1 × b / a. This indicates that the surface shape on the compensating mirror and the corresponding constructed surface shape on the compensated mirror are similar, and the similarity ratio between the compensated mirror surface shape and the compensating mirror constructed surface shape is b / a. The compensated mirror needs a constructed surface shape that is similar to the compensating mirror surface (similarity ratio b / a) and has the opposite deformation direction to cancel the optical path difference. If there is no surface shape with the opposite deformation to cancel the phase difference, the compensating mirror surface shape can be directly superimposed onto the compensated mirror surface shape through similar scaling to statistically accumulate the error effect. Similarly, while ensuring the optical path difference remains unchanged, the compensated mirror surface shape can also be superimposed onto the compensating mirror through similar scaling for unified processing. Since the surface shape between two mirrors can be approximated by similar superposition, this application uses an active thermal compensation component to generate a specific surface shape for the compensation mirror. This surface shape is then superimposed onto the compensated mirror to compensate for its initial thermal surface shape, thereby improving the final surface shape. Considering the power limit of the electric heating element, the curvature and higher-order terms in the surface shape are processed separately, and only the higher-order terms in the surface shape are compensated by the active thermal compensation component.

[0033] This application utilizes the cumulative effect of surface shape errors in reflectors to simultaneously compensate for the surface shape of multiple reflectors using a single active thermal compensation component. Furthermore, mechanical bending technology is employed to further reduce the overall heat input of the active thermal compensation component. This provides a novel approach to the design of overall cable cooling solutions.

[0034] This application utilizes the similarity of the surface shapes between two mirrors to handle the cumulative error caused by thermal deformation of each mirror on the beamline. The error generated by the thermal surface shape of each mirror on the beamline is decomposed into curvature and higher-order terms, which are processed separately. The curvature is corrected by bending, while the higher-order terms are corrected by an active thermal compensation system. An active thermal compensation component is installed on the plane mirror, with the bending mirror positioned downstream. The bending mirror simultaneously corrects the curvature error of both mirrors, and the active thermal compensation component of the plane mirror simultaneously corrects the higher-order terms in the thermal surface shapes of both mirrors. The initial surface shape of the bending mirror is scaled and superimposed onto the plane mirror for normalization, and the curvature of the superimposed surface shape is removed to obtain the higher-order terms. Using the higher-order terms in the composite surface shape superimposed on the plane mirror as the target, the power of each electric heating element in the active thermal compensation component is calculated using software optimization algorithms or other optimization algorithms to minimize the surface shape of the entire beam spot area. Compensating only for the higher-order terms in the surface shape using the active thermal compensation component can effectively reduce the output power of the electric heating elements.

[0035] The technical solution of this application will be further explained below with reference to specific implementation.

[0036] Example 1: Let's take a side-mounted mirror in a certain beam as an example for illustration. For example... Figure 4 and Figure 5 As shown, the entire line is irradiated with XFEL photons at a repetition frequency of 100kHz and a wavelength of 15nm. The side-mounted plane mirror 100 is positioned at the front end. The active thermal compensation component can consist of multiple uniformly distributed electric heating elements 200; preferably, if a cooling component is provided on the side-mounted plane mirror 100, some of the electric heating elements 200 can be distributed on the surface of the cooling component. Each electric heating element 200 is electrically connected to a heating controller, and the output power of different heating elements is adjusted by controlling the current or voltage of each electric heating element 200 to compensate for the thermal surface shape. The light source point beam propagates 120m and irradiates the optical surface of the plane mirror at a grazing angle of 26mrad, forming a long strip-shaped side-mounted plane mirror light spot 300 with a length of 750.4mm and an absorbed heat load of 20.09W. The light beam reflected by the side-mounted plane mirror 100 continues to propagate for 1m, and then grazes onto the surface of the side-mounted bent mirror 400 at a grazing angle of 24.6mrad, forming a long strip-shaped side-mounted bent mirror spot 500 with a length of 800mm and an absorbed heat load of 15.11W. All mirrors are made of monocrystalline silicon.

[0037] Using the surface shape of the meridian of the light spot region as an evaluation index for surface shape error, such as Figure 6As shown, the initial surface height error of the spot region of the side-mounted plane mirror 100 without active thermal compensation from the electric heating element is 91.09 nm (RMS), and the slope error is 769.4 nrad (RMS). After deducting the curvature, the height error of the higher-order terms is 22.71 nm (RMS), and the slope error is 488.13 nrad (RMS). The initial surface height error of the spot region of the side-mounted bending mirror 400 is 34.19 nm (RMS), and the slope error is 571.01 nrad (RMS). Due to the large difference between its surface curve and the quadratic curve, the higher-order terms account for a large proportion. After deducting the curvature, the height error of the higher-order terms is 34.09 nm (RMS), and the slope error is 578.47 nrad (RMS). The height error of the high-order portion of the surface shape of the 400mm spot region of the side-mounted bending mirror, scaled proportionally to the spot length of the 100mm spot region of the side-mounted plane mirror, is 18.99nm (RMS), and the slope error is 474.74nrad (RMS). Using the high-order portion of the composite surface shape superimposed on the compensation mirror as the target, the power of each electric heating element in the active thermal compensation component is calculated using an optimization algorithm. While ensuring that the maximum output power of each electric heating element is 20W, the superimposed surface shape of the high-order portion of the spot region is minimized. The optimized output power of each electric heating element is shown in [the figure]. Figure 7 .

[0038] See Figure 8 Control instructions were written according to the optimized output power of each electric heating element, and the actual surface shape of the side-mounted plane mirror 100 was controlled by the heating controller to obtain the compensated surface shape. The compensated thermal surface shape of the side-mounted plane mirror 100 was scaled proportionally to the spot area of ​​the side-mounted bending mirror 400 and then linearly superimposed for the second time. The bending mechanism of the side-mounted bending mirror 400 was used to remove the curvature part in the thermal surface shape after the second superposition, and the final surface shape height error was 0.76 nm (RMS), and the slope error was 94.25 nrad (RMS), and the surface shape was significantly improved.

[0039] The surface compensation effect was verified using optical tracking software, with the focal point located 3 meters downstream of the side-mounted bending mirror 400. Since the side-mounted mirror only adjusts the beam intensity along the X-direction, only the beam intensity distribution along the X-direction of the focused beam was compared, and the intensity was normalized. (See attached image.) Figure 9Assuming no thermal surface shape is generated in each mirror, i.e., when an ideal light spot is produced, the full width at half maximum (FWHM) of the light spot in the X direction is 4.95 μm. If the side-mounted plane mirror 100 does not use an active thermal compensation component, and only the side-mounted bending mirror 400 is used to eliminate curvature, the FWHM of the light spot in the X direction is 9.9 μm, which is 100% larger than the ideal light spot, and the peak light intensity is only 50% lower than the ideal light spot. If the side-mounted plane mirror 100 uses an active thermal compensation component, and is used in conjunction with the side-mounted bending mirror 400 to eliminate curvature, i.e., using the scheme of Example 1, the FWHM of the light spot in the X direction is 5.7 μm, which is only 15% larger than the ideal light spot, and the peak light intensity is only 14% lower than the ideal light spot. This proves that the scheme can achieve good surface shape compensation effect and improve the beam quality during beam transmission.

[0040] Example 2: Let's take a flat mirror in a certain beam as an example for illustration, such as... Figure 10 and Figure 11 As shown. The entire line is irradiated with XFEL photons at a repetition frequency of 100kHz and a wavelength of 15nm. A flat plane mirror 600 is placed at the front end, and the active thermal compensation component can be composed of multiple uniformly distributed electric heating elements 200. Similar to Embodiment 1, the surface shape is adjusted by controlling the heat output of each electric heating element. The light source beam propagates 135m and irradiates the optical surface of the plane mirror at a grazing angle of 26mrad, forming a long strip-shaped flat plane mirror spot 700 with a length of 800mm and an absorbed heat load of 20.21W. The beam reflected by the flat plane mirror 600 continues to propagate 1m and grazes the surface of the flat bent mirror 800 at a grazing angle of 26.2mrad, forming a long strip-shaped flat bent mirror spot 900 with a length of 800mm and an absorbed heat load of 14.16W. All mirrors are made of monocrystalline silicon.

[0041] Using the surface shape of the meridian of the light spot region as an evaluation index for surface shape error, such as Figure 12As shown, the initial surface height error of the spot region of the flat plane mirror 600 without active thermal compensation from the electric heating element is 43.25 nm (RMS), and the slope error is 350.93 nrad (RMS). After deducting the curvature, the height error of the higher-order terms is 9.06 nm (RMS), and the slope error is 202.17 nrad (RMS). The initial surface height error of the spot region of the flat bending mirror 800 is 38.99 nm (RMS), and the slope error is 605.92 nrad (RMS). Due to the large difference between its surface curve and the quadratic curve, the higher-order terms account for a large proportion. After deducting the curvature, the height error of the higher-order terms is 37.54 nm (RMS), and the slope error is 631.71 nrad (RMS). Since the spot lengths of the side-mounted bending mirror 400 and the flat-mounted plane mirror 600 are the same, the surface shape of the spot area of ​​the flat-mounted bending mirror 800 can be directly superimposed onto the spot area of ​​the flat-mounted plane mirror 600. The height error of the higher-order portion of the superimposed overall surface shape is 31.71 nm (RMS), and the slope error is 562.28 nrad (RMS). Taking the higher-order portion of the overall surface shape superimposed on the compensation mirror as the target, the power of each electric heating element in the active thermal compensation component is calculated using the software optimization algorithm. While ensuring that the maximum output power of each electric heating element is 20W, the superimposed surface shape of the higher-order portion of the spot area is minimized. The optimized output power of each electric heating element is shown in [the figure]. Figure 13 .

[0042] See Figure 14 Control instructions were written according to the optimized output power of each electric heating element. The actual surface shape of the flat plane mirror 600 was controlled by the heating controller to obtain the compensated surface shape. The compensated hot surface shape of the flat plane mirror 600 was directly superimposed on the spot area of ​​the flat bending mirror 800. The bending mechanism of the flat bending mirror 800 was used to remove the curvature part of the hot surface shape after the second superposition. The final surface shape height error was 0.45nm (RMS), and the slope error was 44.1nrad (RMS), and the surface shape was significantly improved.

[0043] The surface compensation effect was verified using optical tracking software, with the focal point located 2 meters downstream of the flat-mounted bending mirror 800. Since the side-mounted mirror only adjusts the beam intensity along the Y-direction, only the beam intensity distribution along the Y-direction of the focused beam was compared, and the intensity was normalized. See [link to documentation]. Figure 15Assuming no thermal surface shape is generated in each mirror, i.e., when an ideal light spot is produced, the full width at half maximum (FWHM) of the light spot in the Y direction is 3.3 μm. If the flat plane mirror 600 does not use an active thermal compensation component, and only the flat bending mirror 800 is used to eliminate curvature, the full width at half maximum (FWHM) of the light spot in the Y direction is 9.2 μm, which is 179% larger than the ideal light spot, and the peak light intensity is only 41% lower than the ideal light spot. If the side-mounted plane mirror 100 uses an active thermal compensation component, and is used in conjunction with the flat bending mirror 800 to eliminate curvature, i.e., using the scheme of Example 1, the full width at half maximum (FWHM) of the light spot in the Y direction is 3.6 μm, which is only 10% larger than the ideal light spot, and the peak light intensity is only 12% lower than the ideal light spot. This proves that the scheme can achieve good surface shape compensation effect and improve the beam quality during beam transmission.

[0044] Corresponding to the above method, embodiments of this application also provide a collaborative control device for multiple laser beamline reflectors, such as... Figure 16 As shown, the device includes: The acquisition unit 1610 is used to acquire the attribute parameters of the current compensated mirror and the upstream mirror of the compensated mirror among multiple mirrors; wherein the upstream mirror of the compensated mirror includes an active thermal compensation component. The compensation unit 1620 is used to control the active thermal compensation component to compensate the compensated mirror based on the attribute parameters of the compensated mirror and the upstream reflector of the compensated mirror.

[0045] The functions of each functional unit of the collaborative control device for laser beamline multi-reflectors provided in the above embodiments of this application can be implemented through the above-described method steps. Therefore, the specific working process and beneficial effects of each unit in the collaborative control device for laser beamline multi-reflectors provided in the embodiments of this application will not be repeated here.

[0046] This application also provides an electronic device, such as... Figure 17 As shown, it includes a processor 1710, a communication interface 1720, a memory 1730, and a communication bus 1740, wherein the processor 1710, the communication interface 1720, and the memory 1730 communicate with each other through the communication bus 1740.

[0047] Memory 1730 is used to store computer programs; When processor 1710 executes a program stored in memory 1730, it performs the following steps: The attribute parameters of the current compensated mirror and the upstream mirror of the compensated mirror are obtained from multiple mirrors respectively; wherein the upstream mirror of the compensated mirror contains an active thermal compensation component. Based on the property parameters of the compensated mirror and the upstream reflector, the active thermal compensation component is controlled to compensate the compensated mirror.

[0048] The communication bus mentioned above can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not mean that there is only one bus or one type of bus.

[0049] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0050] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0051] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0052] The implementation methods and beneficial effects of the various components of the electronic device in the above embodiments for solving the problem can be found in [reference needed]. Figure 2 The steps in the illustrated embodiments are used to implement the electronic device. Therefore, the specific working process and beneficial effects of the electronic device provided in this application will not be repeated here.

[0053] In another embodiment provided in this application, a computer-readable storage medium is also provided, which stores instructions that, when executed on a computer, cause the computer to perform the cooperative control method of the laser beamline multi-reflector described in any of the above embodiments.

[0054] In another embodiment provided in this application, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute the cooperative control method of the laser beamline multi-reflector described in any of the above embodiments.

[0055] Those skilled in the art will understand that the embodiments in this application can be provided as methods, systems, or computer program products. Therefore, the embodiments in this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the embodiments in this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0056] This application describes embodiments of methods, apparatus (systems), and computer program products according to embodiments of this application with reference to flowchart illustrations and / or block diagrams. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0057] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0058] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0059] Although preferred embodiments have been described in this application, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of this application.

[0060] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of this application and its equivalents, then these modifications and variations are also intended to be included in the embodiments of this application.

Claims

1. A method for coordinated control of multiple reflectors in a laser beamline, characterized in that, The laser beamline multi-reflector includes multiple reflectors, and the method includes: The attribute parameters of the current compensated mirror and the upstream mirror of the compensated mirror are obtained from multiple mirrors respectively; wherein the upstream mirror of the compensated mirror includes an active thermal compensation component. The active thermal compensation component is controlled to compensate the compensated mirror based on the attribute parameters of the compensated mirror and the upstream reflector.

2. The method as described in claim 1, characterized in that, Based on the property parameters of the compensated mirror and the upstream reflector, the active thermal compensation component is controlled to compensate the compensated mirror, including: Based on the property parameters of the compensated mirror and the upstream reflector, the target surface shape to be compensated is determined. Based on the target surface shape to be compensated, the attribute parameters of the compensated mirror and the upstream reflector of the compensated mirror, the target power of the active thermal compensation component is determined. Based on the target power, the property parameters of the upstream reflector of the compensated mirror, and the property parameters of the compensated mirror, the active thermal compensation component is used to compensate the compensated mirror.

3. The method as described in claim 2, characterized in that, The properties of the upstream reflector of the compensated mirror include: grazing angle and initial thermal surface shape; the properties of the compensated mirror include: grazing angle, initial thermal surface shape, material elastic modulus and moment of inertia.

4. The method as described in claim 3, characterized in that, Based on the property parameters of the compensated mirror and the upstream reflector, the target surface shape to be compensated is determined, including: Based on the grazing angles of the compensated mirror and the upstream reflector, the initial thermal surface shape of the compensated mirror is mapped onto the reflector, and surface shape decoupling processing is performed to obtain the target surface shape.

5. The method as described in claim 3, characterized in that, Based on the target surface shape to be compensated, the attribute parameters of the compensated mirror and the upstream reflector of the compensated mirror, the target power of the active thermal compensation component is determined, including: Based on the pre-constructed power-surface coupling model, the initial thermal surface shape and grazing angle of the compensated mirror and the upstream reflector of the compensated mirror, the target power of the active thermal compensation component corresponding to the target surface shape is determined with the target surface shape as the optimization target.

6. The method as described in claim 3, characterized in that, Based on the target power, the property parameters of the upstream reflector of the compensated mirror, and the property parameters of the compensated mirror, the active thermal compensation component is used to compensate the compensated mirror, including: The active thermal compensation component is controlled to heat the upstream mirror of the compensated mirror with the target power, so that the upstream mirror of the compensated mirror produces a target compensation surface shape with the opposite direction to the target surface shape; Based on the grazing angles of the compensated mirror and the upstream reflector, the target compensation surface shape is mapped onto the compensated mirror and superimposed with the initial thermal surface shape of the compensated mirror to compensate the compensated mirror.

7. The method as described in claim 6, characterized in that, The compensated mirror includes a mechanical bending assembly; the attribute parameters of the compensated mirror also include: the lever arm of the mechanical bending assembly; After mapping the target compensation surface shape onto the compensated mirror and superimposing it with the initial thermal surface shape of the compensated mirror, the method further includes: The surface shape of the compensated mirror after superimposing the target compensation surface shape is taken as the comprehensive surface shape; Determine the curved surface shape in the composite surface shape; Based on the bending surface shape, the elastic modulus of the material of the compensated mirror, the moment of inertia of the section, and the lever arm, the target bending parameters of the mechanical bending assembly are determined. The mechanical bending assembly is controlled to bend the compensated mirror with the target bending parameters, so that the compensated mirror produces a compensation surface shape that is opposite to the direction of the bending surface shape, thereby completing the compensation of the compensated mirror.

8. A collaborative control device for multiple reflectors in a laser beamline, characterized in that, The laser beamline multi-reflector includes multiple reflectors, and the device includes: The acquisition unit is used to acquire the attribute parameters of the current compensated mirror and the upstream mirror of the compensated mirror among a plurality of mirrors; wherein the upstream mirror of the compensated mirror includes an active thermal compensation component. The compensation unit is used to control the active thermal compensation component to compensate the compensated mirror based on the attribute parameters of the compensated mirror and the upstream reflector of the compensated mirror.

9. An electronic device, characterized in that, The electronic device includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the method of any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method described in any one of claims 1-7.

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