CN113311580B - Method for preparing differential array beam wavefront corrector based on aberration measurement - Google Patents

Abstract

The invention discloses a method for preparing a differential array beam wavefront corrector based on aberration measurement, which comprises the following steps of: measuring the distortion wavefront deviation of each sub-beam in an array beam comprising a plurality of sub-beams, performing three-dimensional modeling on the integrated wavefront corrector by using three-dimensional modeling software, importing the model into simulation software for simulation optimization, judging whether the deformation and the resonance frequency of each sub-beam distorting lens of the corrector meet the design requirements, and if so, recording the structural parameters of a lens body; otherwise, the three-dimensional modeling is carried out again to continue the simulation optimization until the design requirement is met; and preparing a differential wavefront corrector according to the structural parameters of the lens body. The invention has the advantages of low cost, compact system structure, customized design, high correction efficiency and the like.

Description

A Differential Array Beam Wavefront Corrector Fabrication Method Based on Aberration Measurement

technical field

The invention relates to the fields of incoherent array laser synthesis and adaptive optics, in particular to a method for preparing a differential array beam wavefront corrector based on single-beam aberration measurement.

Background technique

Traditional high-energy laser systems generally use a single high-power laser as the laser light source, which has complex thermal management, poor beam quality, and poor mobility. At present, the array synthesis of the beams emitted by multiple low-power lasers is one of the effective ways to achieve high-power laser output.

Array beam synthesis refers to arranging multiple single beams according to a certain spatial position to form an array beam and then synthesize and output it. Array beam combining can be divided into coherent combining and non-coherent combining.

According to the basic principles of physical optics, to achieve stable interference, the frequency and polarization state of each beam must be the same, and the phase difference of each beam must be constant. In fact, the intensity of coherent combined light is related to factors such as the spatial position, laser power, polarization state, line width, optical path difference, inclined wavefront, high-order wavefront distortion, and phase noise of the single laser. Therefore, the coherent combination system needs to optimize the control of various parameters (polarization state, phase, optical path difference, optical axis, and tilt) to achieve the optimal coherent combination effect in the process of optimizing the extreme value of the performance evaluation function. Mathematically, incoherent combination can be simply understood as the direct superposition of the light intensity of each sub-beam. The light intensity of incoherent combination is only related to the spatial position, laser power, inclined wavefront and high-order wavefront distortion of a single laser. The incoherent combination system does not need to control the optical path difference and polarization of each beam, and the system structure is relatively simple to implement. .

Compared with a single beam, the sub-beams incoherently combined by the array beam are incoherent, which can effectively suppress the light intensity fluctuation at the receiving end and the flicker of the target image caused by atmospheric turbulence, and it is easier to obtain a good lighting effect, so the array beam is incoherent Synthesis is widely used in laser active illumination imaging systems. In this regard, domestic and foreign institutions such as Japan, the US Naval Laboratory, and the Changchun Institute of Optics and Mechanics of the Chinese Academy of Sciences have conducted a large number of experimental studies.

For incoherent array beams, transmission through turbulent atmosphere and free space will also cause beam quality degradation and energy density decline due to many factors such as light intensity flickering, fluctuations, and expansion. Adaptive optics technology is used to realize wavefront regulation of incoherent array beams. Compensating the wavefront distortion of each beam can further improve the beam quality and energy density at the receiving end of the incoherent array beam, which has important application value.

Adaptive optics (AO) is a comprehensive discipline integrating science and engineering. It studies the theory, system, technology and engineering of real-time automatic improvement of the quality of optical wavefronts. In terms of technical realization, it is a kind of automatic control system that takes the optical wavefront as the control object, uses the wavefront sensor, and uses a set of control algorithms and hardware as the controller, and the wavefront corrector as the actuator.

The adaptive optics system consists of three basic components: a wavefront sensor 5, a wavefront controller 6, a wavefront corrector 7, a beam splitter 8, and a high-resolution camera 10, etc., as shown in Figure 1. Among them, the deformable mirror is an important part of the wavefront corrector 7, as shown in FIG. 2 . The deformable mirror actively regulates the incident distorted wavefront so that the outgoing wavefront meets the system requirements.

In terms of adaptive wavefront control of incoherent array beams, the existing method is to use multiple wavefront correctors to individually adjust the tilt or high-order aberration of each sub-beam of the incoherent array beam, that is, to use N sets of adaptive optics systems , each sub-beam of the N-way incoherent array beam is independently regulated. This technical solution makes the optical system very large. For N wavefront sensors and N wavefront correctors, due to the strict spatial alignment relationship with the sub-beams of the incoherent array beam, more requirements are put forward for system assembly. Stringent requirements. In the disclosed technology, the use of traditional adaptive optics system to carry out wavefront manipulation of arrayed beams has not been reported. Based on the traditional AO idea to correct the wavefront of the array beam, one idea is to combine multiple wavefront correctors in a certain arrangement, and the other idea is to find a single wavefront corrector that matches the array beam. The combined arrangement of multiple wavefront correctors makes the structure of the optical system larger, and the requirements for the assembly of each device and the positional relationship of each device are more stringent. At the same time, it also increases the difficulty of device support and makes it more difficult to control and use. With a higher technical level, it is easy to cause the paralysis of multiple wavefront correction devices due to the damage of one wavefront correction device, which in turn leads to the collapse of the entire system.

For the idea of using the existing single wavefront corrector to correct the wavefront aberration of the array beam, the discretely driven continuous mirror deformable mirror (Deformable mirror, DM) electrodes are mostly arranged in a square pattern that does not match the circular distribution of the array beam; Mirrors (MEMS) and liquid crystal spatial light modulators (LC DM) are generally small in diameter, which are not suitable for wavefront correction of array beams; each sub-mirror of spliced sub-mirror deformable mirrors only corrects tilt aberration, and there are gaps between sub-mirrors. The energy utilization rate is low and the adjustment is difficult; the film material of the thin film deformable mirror (MMDM) is brittle and the resonance frequency is low, so it is not suitable for use in the array beam combining system; the diameter of the bimorph deformable mirror (Bimor _p h DM) is generally larger If the value is small, the deformation cross-connection value between the drivers is large, which is not conducive to the independent control of each sub-region. Considering the above situation, there is no mature deformable mirror fabrication technology suitable for array beam aberration correction.

In the more than ten years of research and development of the honeycomb deformable mirror, it is mainly used as the main mirror of the optical telescope, that is, as a multi-unit deformable mirror to correct the aberration of an incident wavefront. The main purpose of adopting the honeycomb structure design is to realize the lightweight support of the large-aperture primary mirror. The other is used in a single-channel laser transmission system for wavefront correction, and is also used as a single deformable mirror to correct single-channel wavefront distortion. There is no report on the application of such deformable mirrors for wavefront correction of arrayed beams.

Disadvantages or deficiencies of the current technology: the arrangement of the driver electrodes in each cell is the same, the wavefront aberration correction capability is the same, there is no targeted design according to the aberration characteristics of the incident beam corresponding to each cell, and the design flexibility is lacking. Since each beam comes from an independent laser and optical transmission link during array beam synthesis, the aberration components contained in it are also different, so the wavefront correction capability requirements of each beam are different, so there is no differentiated driver The design of honeycomb deformable mirror cannot be directly applied to solve the problem of wavefront correction of arrayed beams.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a low-cost, high-correction-efficiency differential array beam wavefront corrector preparation method based on single-beam aberration measurement.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A differential array beam wavefront corrector based on aberration measurement, including a mirror body with a mirror surface on the front, and a plurality of sub-beam correction components on the back of the mirror body, and the structure between the multiple sub-beam correction components Some or all of them are different. When the array beam containing multiple sub-beams is irradiated on the mirror surface of the mirror body, each sub-beam correction component performs differential wavefront pixel correction on the sub-beams in the area, so that the wavefront of each sub-beam correction component The pixel correction amount is equal to the distortion wavefront deviation of the corresponding sub-beam.

As a further improvement to the above technical solution:

The sub-beam correction component includes a substrate and a piezoelectric component connected to each other, and the piezoelectric component is provided with a whole ground electrode on the side facing the substrate, and a discrete electrode is provided on the side away from the substrate and facing the mirror body, and the Some or all of the discrete electrodes are different among the plurality of sub-beam correction components.

The piezoelectric component is a piezoelectric material layer.

The back of the mirror body is provided with a plurality of grooves, and the bottom of each groove is provided with a protruding fixing bracket, and a sub-beam correction component is installed on each fixing bracket.

The mirror body has an integrated structure; or the mirror body is a split structure formed by splicing multiple blocks, and each block is provided with a sub-beam correction component, and the block is a polygonal structure, And the plurality of blocks are detachably plugged and mounted on the same fixing fixture.

The polygonal structure is a honeycomb structure or a square structure or a strip structure.

The substrate is glass or silicon substrate.

As a general inventive concept, the present invention also provides a design method of the aforementioned differential array beam wavefront corrector based on aberration measurement, comprising the following steps:

1) measuring the distortion wavefront deviation of each sub-beam in an array beam comprising a plurality of sub-beams;

2) Establish a three-dimensional model of the differential array beam wavefront corrector, and import the three-dimensional model of the differential array beam wavefront corrector into the finite element analysis software;

3) In the finite element analysis software, according to the structural parameters of the differential array beam wavefront corrector, adjust the structural parameters of each sub-beam correction component and perform simulation calculations for each sub-beam correction component to the corresponding sub-beam irradiated on the mirror surface Wavefront pixel correction effect, if each sub-beam correction component performs differential wavefront pixel correction on the sub-beams in the area, so that the wavefront pixel correction amount of each sub-beam correction component is equal to the distortion wavefront deviation of the corresponding sub-beam, Then it is judged that the detection simulation results meet the design requirements, and the final structural parameters of the differential array beam wavefront corrector are output as the obtained design results, and the end and exit; otherwise, skip to step 3) to continue to adjust the correction of each sub-beam The structural parameters of the component.

As a further improvement to the above technical solution:

Step 1) includes:

S1-1. According to the spatial position of the sub-beams of the array beam, the sub-apertures of the microlens array of the wavefront sensor are divided into multiple sub-areas, each sub-area contains multiple sub-apertures, and the sub-beams of the array beam pass through the micro-lens arrays of the corresponding areas respectively. The lens sub-aperture is focused on the camera target surface to form a spot;

S1-2. Taking the position of the light spot of the reference wavefront in the corresponding target area as a reference, calculate the deviations Δx and Δy between the sub-beam distortion wavefront of the array beam and the centroid position of the reference wavefront;

S1-3, calculating the phase distortion information of the incident wavefront of the sub-beams of the array beam according to the deviation Δx and Δy, and obtaining the distorted wavefront deviation of each sub-beam in the array beam comprising a plurality of sub-beams;

Adjusting the structural parameters of each sub-beam correction component in step 3) includes adjusting the unit distribution of the discrete electrodes of each sub-beam correction component and the aperture ratio between the sub-beam correction component and the mirror body.

After step 2) and before step 3), it also includes repeatedly iteratively adjusting the thickness of each sub-beam correction component, the thickness of the mirror body, and the adhesion between the sub-beam correction component and the mirror body for the structural parameters of the differential array beam wavefront corrector. The thickness of the bonding layer is such that the deformation and resonance frequency of the differential array beam wavefront corrector meet the design requirements.

As a general inventive concept, the present invention also provides a method for preparing a differential array beam wavefront corrector based on aberration measurement. The design method obtains the structural parameters of the differentiated array beam wavefront corrector; and then processes and prepares the differentiated array beam wavefront corrector according to the obtained differentiated array beam wavefront corrector.

Compared with the prior art, the present invention has the advantages of:

What the present invention is aimed at is that the incident beam is an array beam rather than a single beam, which is different from the traditional sensor for measuring the wavefront of a single beam. +N wavefront sensors) work in parallel in a complex mode, reduce the scale of the adaptive optics system, improve the efficiency of wavefront correction, and adopt an integrated wavefront correction system, that is, use a sensor and a wavefront corrector (integrated deformable mirror) At the same time, the wavefront aberration of N-way array beams is measured and closed-loop corrected. This solution can greatly reduce the volume and scale of the array beam aberration correction system, reduce system cost, simplify the system adjustment process, and promote the array beam wavefront aberration correction. The system is really moving towards engineering practicality.

The present invention is based on the idea of integrated design. An integrated multi-area independent control deformable mirror is designed and manufactured on the corrector, so that each independent control area matches the spatial arrangement of the sub-beams of the array beam, and each area has the ability to correct the incident wavefront aberration distortion. The ability to solve the array beam wavefront correction problem at the lowest cost and highest efficiency. It should be emphasized that the independent control of the wavefront corrector (integrated deformable mirror) can be determined according to the number of beams and the spatial arrangement of the array beam. The specific arrangement of the piezoelectric components (drivers) can also be tailored according to the incident beam aberration corresponding to the area, which has great design flexibility and scalability.

Description of drawings

Figure 1 is a block diagram of the adaptive optics system.

Fig. 2 is a schematic diagram of the function of the wavefront corrector deformable mirror in adaptive optics.

Fig. 3 is a flow chart of the present invention.

Figure 4 is a schematic diagram of the integrated wavefront sensor wavefront measurement.

FIG. 5 is a structural model of the 7×1 integrated wavefront corrector in this embodiment.

FIG. 6 is a grid division result diagram of the 7×1 integrated wavefront corrector in this embodiment.

FIG. 7 is a structural dimension diagram of the 7×1 integrated wavefront corrector in this embodiment.

Fig. 8 is a specific design flow chart of the 7×1 integrated wavefront corrector in this embodiment.

Fig. 9 is a schematic diagram of the arrangement of electrodes in each honeycomb of the 7×1 differential array beam wavefront corrector in this embodiment.

Fig. 10 is a schematic diagram of the structure of a corrector layer in a single cell.

Fig. 11 is an assembled three-dimensional structure diagram (back side) of the differentiated wavefront corrector of the present invention.

Fig. 12 is an assembly front structural view of the differential wavefront corrector of the present invention.

Fig. 13 is an assembly structure diagram of the differential wavefront corrector of the present invention.

illustration:

1. Mirror body; 11. Groove; 12. Fixing bracket; 2. Sub-beam correction component; 21. Base; 22. Piezoelectric component; 221. Ground electrode; 222. Discrete electrode; 23. Support structure; 3. Fixing fixture; 4. Base; 5. Wavefront sensor; 6. Wavefront controller; 7. Wavefront corrector; 8. Spectroscope; 9. High-resolution camera.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise specified, the instruments or materials used in the present invention are commercially available.

A differential array beam wavefront corrector based on aberration measurement of the present invention includes a mirror body 1 with a mirror surface on the front, a plurality of sub-beam correction components 2 are arranged on the back of the mirror body 1, and one of the plurality of sub-beam correction components 2 The structures between them are partly or completely different. When the array beam containing multiple sub-beams is irradiated on the mirror surface of the mirror body 1, each sub-beam correction component 2 performs differential wavefront pixel correction on the sub-beams in the area, so that each sub-beam The wavefront pixel correction amount of the correction component 2 is equal to the distorted wavefront deviation of the corresponding sub-beam.

The sub-beam correction assembly 2 includes a substrate 21 and a piezoelectric assembly 22 connected to each other. The piezoelectric assembly 22 is provided with a whole ground electrode 221 on the side facing the substrate 21, and a discrete electrode 221 is provided on the side away from the substrate 21 and facing the mirror body 1. The electrodes 222, and the discrete electrodes 222 between multiple sub-beam correction components 2 are partially or completely different.

The piezoelectric component 22 is a layer of piezoelectric material.

The sub-beam correction assembly 2 further includes a support structure 23 on which the base 21 is supported, and the support structure 23 is located on one side of the piezoelectric assembly 22 .

The back of the mirror body 1 is provided with a plurality of grooves 11 , and the bottom of each groove 11 is provided with a protruding fixing bracket 12 , and each fixing bracket 12 is equipped with a sub-beam correction assembly 2 .

In Embodiment 1, the mirror body 1 has an integrated structure; in other embodiments, the mirror body 1 is a split structure formed by splicing multiple blocks, and each block is provided with a sub-beam correction assembly 2. The sub-block is a polygonal structure, and multiple sub-blocks are detachably plugged and installed on the same fixing fixture 3 respectively.

A method for designing a differential array beam wavefront corrector based on aberration measurement in the present invention comprises the following steps:

1) measuring the distortion wavefront deviation of each sub-beam in an array beam comprising a plurality of sub-beams;

2) Establish a three-dimensional model of the differential array beam wavefront corrector, and import the three-dimensional model of the differential array beam wavefront corrector into the finite element analysis software;

3) In the finite element analysis software, according to the structural parameters of the differential array beam wavefront corrector, adjust the structural parameters of each sub-beam correction component 2 and perform simulation calculations for each sub-beam correction component 2 to irradiate the corresponding beam on the mirror surface. The wavefront pixel correction effect of the beam, if each sub-beam correction component 2 performs differential wavefront pixel correction on the sub-beams in the area, so that the wavefront pixel correction amount of each sub-beam correction component 2 is equal to the distortion of the corresponding sub-beam If the wavefront deviation is detected, it is judged that the detection simulation results meet the design requirements, and the structural parameters of the finally obtained differential array beam wavefront corrector are output as the obtained design results, and the end and exit; otherwise, jump to step 3) to continue the adjustment The individual sub-beams correct the structural parameters of the assembly 2 .

Step 1) includes:

S1-1. According to the spatial position of the sub-beams of the array beam, the sub-apertures of the microlens array of the wavefront sensor are divided into multiple sub-areas, each sub-area contains multiple sub-apertures, and the sub-beams of the array beam pass through the micro-lens arrays of the corresponding areas respectively. The lens sub-aperture is focused on the camera target surface to form a spot;

S1-2. Taking the position of the light spot of the reference wavefront in the corresponding target area as a reference, calculate the deviations Δx and Δy between the sub-beam distortion wavefront of the array beam and the centroid position of the reference wavefront;

S1-3, calculating the phase distortion information of the incident wavefront of the sub-beams of the array beam according to the deviation Δx and Δy, and obtaining the distorted wavefront deviation of each sub-beam in the array beam comprising a plurality of sub-beams;

Adjusting the structural parameters of each sub-beam correction assembly 2 in step 3) includes adjusting the unit distribution of the discrete electrodes of each sub-beam correction assembly 2 and the aperture ratio between the sub-beam correction assembly 2 and the mirror body 1 .

After step 2) and before step 3), it also includes repeatedly iteratively adjusting the thickness of each sub-beam correction component 2, the thickness of mirror body 1, the sub-beam correction component 2 and the structure parameters of the differential array beam wavefront corrector. The thickness of the adhesive layer of the mirror body 1 is such that the deformation amount and resonance frequency of the differential array beam wavefront corrector meet the design requirements.

Example 1:

Glossary:

Corrector: It can produce surface shape changes according to the control signal, which is used to correct the wavefront phase distortion of the beam incident on its surface. Divided into tilting mirrors for correcting global oblique aberrations and deformable mirrors for correcting higher-order aberrations.

Deformable Mirror: A type of corrector used to correct higher order aberrations.

Driver: The active unit that performs deformation in the corrector, usually composed of piezoelectric ceramics, magnetostrictive materials, etc.

Electrode: A metal element that is connected to the driver and applies a voltage to the driver, usually in the form of a copper sheet or other metal mask.

As shown in Figure 3, the preparation method of the differential array beam wavefront corrector based on aberration measurement of the present invention, the N-way array beam is incident on the differential array beam wavefront corrector to be processed through the beam splitter (the present invention uses integrated wavefront corrector as an example), and then enter the integrated wavefront sensor through the spectroscope, by measuring the sub-spot position information of each sub-beam on the target surface of the wavefront sensor, the wavefront carried by each sub-beam is obtained by analysis Phase distortion, and then control the integrated wavefront controller according to the feedback of the distortion information to realize the integrated correction of the incident wavefront distortion of each sub-beam, including the following steps:

(1) Measurement and analysis of array beam wavefront aberration: the integrated wavefront sensor is used to measure and analyze the array beam wavefront aberration. The basic measurement principle and structure of the integrated wavefront sensor are similar to those of the Hartmann wavefront sensor, referred to as the Hartmann-like sensor for short. It consists of a microlens array and a large target surface camera. The working principle is shown in Figure 4.

Traditional Hartmann sensors are designed for single-beam incident wavefronts, and Hartmann-like sensors also use microlens array structures, but for multi-wavefront design of array beams, the algorithms used for sensor area division and wavefront restoration are different.

Specific steps are as follows:

A. First, according to the spatial position of each sub-beam of the incident array beam, the sub-apertures of the microlens array are divided into regions (indicated by dotted lines in Figure 4), each sub-region contains a plurality of sub-apertures, and the incident sub-beams pass through the microlenses of the corresponding regions The sub-aperture is focused on the camera target surface, and the spot information on the camera target surface in the sub-area includes the wavefront distortion information of the sub-beam.

B. Select the spot position of the reference wavefront in the corresponding target area as a reference, and calculate the deviations Δx and Δy between the distorted wavefront of the sub-beam and the centroid position of the reference wavefront through the centroid algorithm.

C. Based on the deviation data, that is, the deviation Δx and Δy, restore the phase distortion information of the incident sub-wavefront, or drive the corresponding driver (the piezoelectric component 22 of the sub-beam correction component 2) to the sub-waveform through a direct slope control algorithm. Beam aberrations are corrected.

(2) Finite element design of drive layout

Use COMSOL software to limit the relevant characteristics of the substrate material and piezoelectric material, and carry out the finite element design of the driver layout on the basis of multiple physical fields such as solid mechanics, electrostatics, and piezoelectric effects, and compare a single honeycomb groove under different structural parameters11 Corresponding to changes in the surface PV value, stress and dynamic frequency response of the mirror surface.

In this embodiment, taking the 7×1 integrated wavefront corrector as an example, based on optical processing experience, optical parts with a diameter-thickness ratio greater than 20 are ultra-thin parts. Based on this condition, the honeycomb structure is optimized to ensure that the mirror surface corresponding to a single honeycomb groove 11 will not exceed the allowable stress of the material under a large PV value of the surface shape, and the dynamic frequency response meets the application requirements.

The 7×1 integrated wavefront corrector is modeled three-dimensionally by Solidworks software, and its structural model is shown in Figure 5, where Figure 5(a) is the three-dimensional structure diagram of the model, and Figure 5(b) is the bottom electrode of the model Arrange the schematic diagram, and then import the 3D model into COMSOL software for simulation optimization.

The structural model of the 7×1 integrated wavefront corrector for simulation analysis in COMSOL is shown in Figure 6. This model uses quartz glass or silicon as the substrate 21, as shown in Figure 6(a), and the front is polished and coated. For the light beam reflected and reaching the mirror surface, as shown in Figure 6(b), seven hexagonal honeycomb grooves 11 with a certain depth are dug behind the base 21 according to the symmetrical arrangement of the central circle, and the seven honeycomb grooves 11 At the bottom, circular base bosses with a certain height smaller than the diameter of the grooves are left as fixed supports 12, and 7 pieces of piezoelectric ceramics plated with silver electrodes on both sides are respectively bonded to the circular shape in the 7 honeycomb grooves 11. On the boss of the base, the front of the silver-plated piezoelectric ceramic bonded to the boss is used as a ground electrode, and the back of the 7 piezoelectric ceramics is silver-plated as 7 complete electrodes, so as to apply a static voltage to the piezoelectric ceramic.

Through COMSOL software simulation optimization, determine the structural parameters of the mirror body, as shown in Figure 8. The structural design of the deformable mirror needs to be carried out according to the design requirements, and the number of Zernike items that can be fitted and the fitting accuracy of each item mark the correction of the deformable mirror Therefore, the number of Zernike items and the corresponding fitting accuracy requirements are used as the design entry parameters, so as to design the spatial distribution of electrodes (such as cell distribution, effective aperture ratio), and judge whether the deformation and resonance frequency meet the design requirements. Redesign the spatial distribution of the electrodes, and record the configuration parameters of the deformable mirror if the design requirements are met. The amount of deformation is related to the driver, the adhesive layer (adhesive layer: refers to the colloidal layer that bonds the driver and the mirror surface of the deformable mirror, usually only the thickness and type are different, which will slightly affect the amount of deformation), and the thickness of the lens. When the amount of deformation does not meet the design requirements, optimize the thickness of the driver or the bonding layer or the lens. The resonance frequency is related to the thickness of the driver and the lens. When the resonance frequency does not meet the design requirements, optimize the thickness of the driver and/or the lens, as shown in Figure 7 It shows that the 7×1 integrated wavefront corrector obtained by the present invention has an overall diameter of 50mm and a thickness of 15mm, the diameter of the inscribed circle of each honeycomb groove 11 is 15mm, and the inscribed circle of the six peripheral grooves 11 and the central groove 11 The distance between the centers is 16mm, the thickness of each honeycomb groove 11 corresponds to the mirror surface is 0.6mm, the inner boss diameter of each honeycomb groove 11 is 8mm, the equivalent mirror surface thickness is 1mm, and the piezoelectric ceramic has a diameter of 12mm and a thickness of 0.2mm.

(3) Example of drive design results

Taking the design of a 7×1 integrated wavefront corrector for correcting wavefront aberrations of 7 sub-beams as an example, the correctors can be designed in a honeycomb arrangement. The honeycomb structure uses quartz glass or silicon as the substrate 21, and the front is polished and coated to reflect each sub-beam reaching the mirror surface. According to the symmetrical arrangement of the central circle, seven hexagonal honeycomb grooves of a certain depth are dug on the back of the substrate 21 11, and at the bottom of the seven honeycomb grooves 11, circular base bosses smaller than the diameter of the grooves and having a certain height are respectively left as fixed brackets 12, and 7 pieces of piezoelectric ceramics plated with silver electrodes on both sides are respectively bonded to the On the circular base bosses in the 7 honeycomb grooves 11, the fronts of the silver-plated piezoelectric ceramics bonded to the bosses are used as ground electrodes, and the backs of the 7 piezoelectric ceramics are silver-plated as 7 complete electrodes. Electroceramics apply a static voltage.

According to the wavefront measurement results of each sub-beam, the electrode driver arrangement in each cell can be customized to achieve the optimal correction effect of wavefront aberrations of all sub-beams. The arrangement of electrodes in each cell of the 7-beam differential array beam wavefront corrector is shown in Figure 9. The lines in a single cell in Figure 9 (the lines indicated by the black arrows) are the separation lines of the electrodes (white areas), and the black areas correspond to In the thin strip or ring area, there is no electrode coverage, and no voltage is applied during operation.

The layer structure of a single-cell internal calibrator (a calibrator that can work independently in a single cell, and the entire cellular structure is an array calibrator that can work at the same time and be controlled cooperatively) is shown in Figure 10. In this embodiment, usually a The glass substrate is the substrate 21, and one or two layers of piezoelectric materials with the same size constitute the piezoelectric component 22, and the edge of the substrate 21 is connected to the honeycomb support structure 23 for support and fixation. There is a whole ground electrode 221 between the piezoelectric assembly 22 (piezoelectric material layer) and the substrate 21 (glass substrate), and a plurality of discrete electrodes 222 are distributed on the back of the piezoelectric assembly 22 (piezoelectric material layer), each The arrangement of the discrete electrodes 222 corresponds to the design result of the electrode arrangement in the honeycomb shown in FIG. 9 . According to the incident wavefront aberration of different sub-beams, the present invention carries out the layout design of the electrodes in each sub-region, and finally obtains the wavefront corrector (deformable mirror) and the piezoelectric components 22 ( drives) are arranged differently.

The differential wavefront corrector is divided into mirror body 1, sub-beam correction component 2 (including piezoelectric driver, etc.), electrical connection component, fixing fixture 4 and base 4. The assembly results are shown in Figures 11, 12 and 13 . In Fig. 11, the mirror body 1 is one side of the mirror surface, which is clamped and fixed on the base 4 by the fixing fixture 4. In Fig. 12, the wavefront sensor 5 refers to the electrical connection component, which is connected to the drive electrode control line. Assemblies, in Fig. 13, the sub-beam correction assembly 2 is installed on the electrical connection assembly to obtain a differential array beam wavefront corrector.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with the art, without departing from the scope of the technical solution of the present invention, can use the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent implementation of equivalent changes example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims (8)

1. A differentiation array beam wavefront corrector based on aberration measurement comprises a mirror body (1) with a mirror surface on the front surface, wherein the back surface of the mirror body (1) is provided with a plurality of sub-beam correction components (2), and is characterized in that the structures of the plurality of sub-beam correction components (2) are partially or totally different, when an array beam containing a plurality of sub-beams irradiates on the mirror surface of the mirror body (1), each sub-beam correction component (2) respectively carries out differentiation wavefront pixel correction on the sub-beams in the area, so that the wavefront pixel correction amount of each sub-beam correction component (2) is equal to the distortion wavefront deviation of the corresponding sub-beam;

the sub-beam correction assemblies (2) comprise a substrate (21) and a piezoelectric assembly (22) which are connected with each other, one side of the piezoelectric assembly (22) facing the substrate (21) is provided with a whole block of earth electrode (221), one side of the piezoelectric assembly (22) far away from the substrate (21) and facing the mirror body (1) is provided with a discrete electrode (222), and the discrete electrodes (222) between the sub-beam correction assemblies (2) are partially or totally different;

the mirror body (1) is of an integrated structure; or the mirror body (1) is of a split structure formed by splicing a plurality of blocks, each block is provided with a sub-beam correction assembly (2), the blocks are of polygonal structures, and the blocks are detachably spliced and installed on the same fixing clamp respectively.

2. The wavefront corrector for differentiated array beams of claim 1, characterized in that the piezoelectric component (22) is a layer of piezoelectric material.

3. The wavefront corrector for the light beam of the differential array according to claim 1, characterized in that the back of the mirror body (1) is provided with a plurality of grooves (11), the bottom of each groove (11) is provided with a convex fixing support (12), and each fixing support (12) is provided with a sub-beam correction assembly (2).

4. A method for designing a wavefront corrector for a differential array beam based on aberration measurement according to any one of claims 1 to 3, comprising the steps of:

1) Measuring a distorted wavefront deviation of each sub-beam in an array beam comprising a plurality of sub-beams;

2) Establishing a three-dimensional model of the differential array beam wavefront corrector, and importing the three-dimensional model of the differential array beam wavefront corrector into finite element analysis software;

3) In finite element analysis software, aiming at the structural parameters of a differential array beam wavefront corrector, adjusting the structural parameters of each sub-beam correction component (2) and carrying out simulation calculation on the wavefront pixel correction effect of each sub-beam correction component (2) on the corresponding sub-beam irradiated on a mirror surface, if each sub-beam correction component (2) respectively carries out differential wavefront pixel correction on the sub-beam in the area, so that the wavefront pixel correction value of each sub-beam correction component (2) is equal to the distorted wavefront deviation of the corresponding sub-beam, judging that the detection simulation result meets the design requirement, outputting the finally obtained structural parameters of the differential array beam wavefront corrector as the obtained design result, and ending and exiting; otherwise, skipping to execute the step 3) to continue to adjust the structural parameters of each sub-beam correction component (2).

5. The method for designing the aberration-measurement-based differentiated array beam wavefront corrector according to claim 4, wherein the step 1) comprises:

s1-1, dividing sub-apertures of a micro-lens array of a wavefront sensor into a plurality of sub-apertures according to the sub-beam space positions of array beams, wherein each sub-aperture comprises a plurality of sub-apertures, and the sub-beams of the array beams are focused on a camera target surface through the sub-apertures of the micro-lenses in corresponding areas to form light spots;

s1-2, with the position of a light spot of a reference wavefront in a corresponding target surface area as a reference, solving the deviation delta x and delta y between the distorted wavefront of the sub-beam of the array beam and the position of the centroid of the reference wavefront;

and S1-3, obtaining phase distortion information of the incident wave fronts of the sub-beams of the array beam according to the deviations delta x and delta y, and obtaining the distortion wave front deviation of each sub-beam in the array beam comprising a plurality of sub-beams.

6. The design method of the aberration measurement based differentiation array beam wavefront corrector according to claim 4, wherein the adjusting the structure parameters of each sub-beam correction assembly (2) in step 3) comprises adjusting the unit distribution of the discrete electrodes (222) of each sub-beam correction assembly (2) and the aperture ratio between the sub-beam correction assembly (2) and the mirror body (1).

7. The method for designing the aberration-measurement-based differentiated array beam wavefront corrector according to claim 4, further comprising, after the step 2) and before the step 3), repeating the step of iteratively adjusting the thickness of each sub-beam correction component (2), the thickness of the mirror body (1), and the thickness of the bonding layer between the sub-beam correction component (2) and the mirror body (1) so that the deformation amount and the resonance frequency of the differentiated array beam wavefront corrector meet the design requirements, for the structural parameters of the differentiated array beam wavefront corrector.

8. The method for manufacturing the aberration measurement-based differential array beam wavefront corrector according to any one of claims 1 to 3 is characterized in that structural parameters of the differential array beam wavefront corrector are firstly obtained by the aberration measurement-based design method for the differential array beam wavefront corrector according to any one of claims 4 to 7; and then processing according to the obtained differentiated array beam wavefront corrector to prepare the differentiated array beam wavefront corrector.

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