Laser beam shaping method and system

Abstract

The present application provides a laser beam shaping method and system, relating to the field of bar packaging technology. The method uses a curved shaping member with a free-form surface on one side to shape the fast-axis beam of a bar laser. The surface of the curved shaping member is fitted by adjusting the Zernike polynomial, and the wave aberration of the curved shaping member after fitting is made to meet a preset value. As a result, the square light spot generated by each bar of the stacked laser array after shaping has a uniform light intensity distribution and sharp edges, thereby solving the problems in the prior art of poor beam quality of the stacked laser array and the difficulty of multiple shaping required by the existing optical shaping method.

Description

Technical Field

[0001] The present application relates to the field of bar packaging technology, and in particular to a laser beam shaping method and system. Background Art

[0002] Smile is a phenomenon that occurs in bar lasers. It is mainly reflected in the fact that the light-emitting points are not on the same horizontal line. This is a phenomenon caused by the warping of the wafer itself or the packaging stress. The value of Smile is defined as the difference between the center of the highest light-emitting point and the center of the lowest light-emitting point. Its value can be 0~10 When using aspheric FAC to collimate bars with larger Smile, the luminous points that are not on the same level are off-axis, such as Figure 1 and Figure 2 As shown, Figure 1 Set the Smile value to 10 The spot of the laser bar after collimation, Figure 2 After collimation, the light spot is coarse and has smearing. This will seriously affect the beam quality of the stacked array light, and further increase the difficulty of secondary shaping in the subsequent optical system.

[0003] In existing technology, achieving a uniform square spot with higher output power requires stacking multiple bars in an array. Due to the large fast-axis divergence angle and Gaussian intensity distribution of LD semiconductor lasers, the stacked array produces a large light-emitting surface with poor uniformity. Furthermore, the smile effect of the bars themselves significantly impacts beam quality. To achieve usable results, a complex optical shaping system is often required to achieve acceptable technical specifications. This not only increases the overall system size, but also requires increased costs and complex commissioning.

[0004] like Figure 3 The figure shows the intensity distribution curve of the fast axis of the bar laser. The fast axis of the bar laser shows a typical Gaussian distribution, while the slow axis shows a super-Gaussian distribution. This kind of light intensity distribution is uneven and has unclear edges, which cannot be used in most applications. Therefore, a more complex secondary shaping system is required to transform it into a flat-top beam. Figure 4 As shown, Figure 4 This is the intensity distribution curve for a flat-top beam. In scientific research, a flat-top distribution with sharp edges is ideal. Therefore, a tertiary shaping system is added, which increases the size of the stacked array system, making it more expensive and more difficult to manufacture.

[0005] In summary, in the existing technology, stacked array lasers used in scientific research pump sources and the medical beauty industry all have relatively complex back-end optical shaping systems. In the scientific research industry, if you encounter a stacked array of bars with a large Smile effect, the shaping system will be more expensive and the debugging process will be difficult, such as using multiple fast-axis collimators and slow-axis collimators. If the Smile effect is reduced from the chip packaging process, the yield is low. In the medical beauty industry, there are higher requirements for the size and uniformity of the light spot, which requires the design of a more complex optical shaping system to achieve it, such as using a light guide cone to homogenize the light spot. However, this method is limited by the luminous area and volume of the stacked array, and the use of a lens group will result in poor spot uniformity. Therefore, in the existing technology, there are still many problems that need to be solved for the light spot shaping of a stacked array of bars with a large Smile effect. Summary of the Invention

[0006] The purpose of this application is to provide a laser beam shaping method and system to improve the technical problems raised in the background technology section.

[0007] To achieve the above objectives, this application provides the following technical solutions:

[0008] In a first aspect, the present application provides a laser beam shaping method, wherein the laser includes a bar to be shaped and a curved surface shaping member arranged corresponding to the bar to be shaped, and the method includes:

[0009] According to the Smile feature of the bar to be shaped, the spherical aberration coefficient and the coma coefficient of the Zernike polynomial of the curved surface shaping component are adjusted to be within a first preset range and a second preset range, respectively, wherein the first preset range and the second preset range are determined based on the Smile feature of the bar to be shaped, and the free-form surface of the curved surface shaping component is fitted according to the adjusted Zernike polynomial, so that the wavefront aberration of the curved surface shaping component after fitting is less than a preset value;

[0010] The determined curved surface shaping member is set in the light-emitting direction of the bar to be shaped, and the curved surface shaping member is used to shape the light beam in the fast axis direction of the bar to be shaped.

[0011] Furthermore, the simulated numerical value of the wave aberration is expressed as:

[0012]

[0013] Wherein, W is the wavefront aberration of the surface shaping element after adjusting the spherical aberration coefficient and the coma coefficient of the Zernike polynomial, and the unit is ; is the refractive index, is the number of luminous points of the bar to be shaped, is the normalized value of the incident height of the principal ray of the curved surface shaping component at the aperture stop in different fields of view; 、 is the coefficient, which has the same meaning as the coefficient of the Zernike polynomial. for , For A8.

[0014] Preferably, after fitting, the wave aberration simulation value of the curved surface shaping component is less than a preset value, and the preset value is 0.89λ, where λ is the calibration wavelength of the curved surface shaping component, and the unit is .

[0015] Furthermore, the Zernike polynomial is:

[0016]

[0017] in, is the optical surface sagittal height, is the curved surface base portion of the curved surface shaping member, wherein, is the cone coefficient, is the curvature of the free-form surface of the curved surface shaping part, is the radius height of the curved surface shaping member in the optical axis direction; is the Zernike polynomial part, are the Zernike polynomial coefficients, are the Zernike polynomial terms, is the number of terms in the Zernike polynomial, is the normalized value of the incident height of the chief ray at the aperture stop for different fields of view, = r / (D / 2), D is the entrance pupil diameter, is the argument angle.

[0018] Preferably, the coefficient of the eighth term of the Zernike polynomial is adjusted so that the edge softening factor of the bar to be shaped after shaping by the curved surface shaping member is within the third preset range, that is, the coefficient of the coma term is adjusted. It is between 0.00001 and 0.005.

[0019] Preferably, the coefficient of the ninth term of the Zernike polynomial is adjusted so that the spot uniformity of the bar to be shaped after being shaped by the curved surface shaping member is within the fourth preset range, that is, the coefficient of the spherical aberration term is adjusted. Between 0.01 and 0.05.

[0020] Furthermore, the curvature of the curved surface base portion of the surface shaping element of the Zernike polynomial is determined according to the fast axis divergence angle of the bar to be shaped. , entrance pupil diameter D and cone coefficient .

[0021] Preferably, the Smile value of the bar to be shaped is 5 to 20. .

[0022] Preferably, the substrate of the curved surface shaping piece is quartz glass.

[0023] A second aspect of the present application provides a laser beam shaping system, which is applied to the method described in the first aspect of the present application, and the system includes:

[0024] A stacked laser array includes a plurality of bars to be shaped arranged along a first direction, wherein the first direction is perpendicular to the arrangement direction of the plurality of single-tube laser chips in the bars to be shaped;

[0025] A curved surface shaping member is provided in the light-emitting direction of the bar to be shaped, and includes a free curved surface and an incident plane. The free curved surface is located on a side away from the bar to be shaped; the incident plane is located on a side close to the bar to be shaped.

[0026] The laser beam shaping method provided in this application can at least achieve the following technical effects:

[0027] This application addresses the Smile effect of a bar laser. By fitting the free-form surface of a curved shaping element with Zernike polynomials, and ensuring that the wavefront aberration of the curved shaping element after fitting is less than a preset value, the micro-curvature of the free-form surface of the curved shaping element is adjusted to adjust the spherical aberration and coma of different normalized entrance pupil diameters, thereby weakening or eliminating the impact of the laser's Smile effect. This results in a uniform intensity distribution and sharp, clear edges after shaping. The method provided by the present invention has the advantages of high beam quality, controllable spot size, simple shaping methods, ease of implementation, reduced costs, and a compact optical shaping system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 The Smile value provided in the background technology section of this application is 10 Schematic diagram of the light spot after the bar laser is collimated;

[0030] Figure 2This is a schematic diagram of coma caused by an off-axis light source provided in the background technology section of this application;

[0031] Figure 3 This is a schematic diagram of the light intensity distribution curve of the fast axis of the bar provided in the background technology section of this application;

[0032] Figure 4 A schematic diagram of the light intensity distribution curve of a flat-top beam provided in the background technology section of this application;

[0033] Figure 5 A schematic flow chart of a laser beam shaping method provided in the Examples section of this application;

[0034] Figure 6 This is a schematic diagram of the curved Smile arrangement provided in the Examples section of this application;

[0035] Figure 7 A schematic diagram of the cross-sectional profile of a curved surface shaping member provided in the embodiments of this application;

[0036] Figure 8 This is a schematic diagram of the overall structure of the curved surface shaping member provided in the embodiments of this application;

[0037] Figure 9 A schematic diagram of the structure of a laser beam shaping system provided in the embodiments of this application;

[0038] Figure 10 This is a schematic diagram of the light spot after the bar to be shaped is shaped by the curved shaping member provided in the embodiment of this application;

[0039] Figure 11 This is a schematic diagram of the fast-axis light intensity distribution of the bar to be shaped after being shaped by the curved shaping member provided in the embodiments of this application;

[0040] Figure 12 Schematic diagram of the wavefront aberration of a curved surface shaping component with partial defocus, spherical aberration and coma using a collimated beam as provided in the embodiments of the present application;

[0041] Figure 13 This is a schematic diagram of the overall optical path of the stacked laser array provided in the embodiments of this application after being shaped by a curved surface shaping member;

[0042] Figure 14 This is a schematic diagram of the light spot of the stacked array laser provided in the embodiments of this application after being shaped by the curved surface shaping member;

[0043] Figure 15 This is a schematic diagram of the fast-axis light intensity distribution curve of the shaped light spot provided in the Examples section of this application;

[0044] Figure 16This is a schematic diagram of the light spot of a stacked laser array using common FAC shaping in the prior art provided in the Examples section of this application;

[0045] Figure 17 A schematic diagram of the fast axis intensity distribution of a stacked laser array using conventional FAC shaping in the prior art provided in the Examples section of this application;

[0046] Reference numerals: 1, bar to be shaped; 2, curved surface shaping member; 21, free-form surface; 22, incident plane. DETAILED DESCRIPTION

[0047] The following will clearly and completely describe the technical solutions of this application in conjunction with the embodiments. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0048] The embodiment of the present application provides a laser beam shaping method, which uses Zernike polynomials to fit the free-form surface of the surface shaping component, thereby adjusting the spherical aberration and coma of different normalized entrance pupil diameters by adjusting the micro-curvature of the free-form surface of the surface shaping component, so as to weaken or eliminate the influence of the laser Smile effect, so that the square light spot obtained after shaping has uniform light intensity distribution and sharp edges. Figure 5 As shown, this embodiment provides a laser beam shaping method, wherein the laser includes a bar to be shaped and a curved surface shaping member arranged corresponding to the bar to be shaped, and specifically includes the following steps:

[0049] Step S100: Based on the Smile feature of the bar 1 to be shaped, the spherical aberration coefficient and the coma coefficient of the Zernike polynomial of the curved surface shaping member 2 are adjusted to be within a first preset range and a second preset range, respectively. The first preset range and the second preset range are determined based on the Smile feature of the bar 1 to be shaped. The free-form surface 21 of the curved surface shaping member 2 is fitted based on the adjusted Zernike polynomials, so that the wavefront aberration of the curved surface shaping member 2 after fitting is less than a preset value.

[0050] Step S200: The determined curved surface shaping member 2 is arranged in the light emitting direction of the bar 1 to be shaped. The curved surface shaping member 2 is used to shape the light beam in the fast axis direction of the bar 1 to be shaped.

[0051] Specifically, in step S100, the Zernike polynomial is expressed as the following formula (1):

[0052] (1)

[0053] In formula (1), is the optical surface sagittal height, is the curved surface base portion of the curved surface shaping member 2, wherein: is the cone coefficient, is the curvature of the free curved surface 21 of the curved surface shaping member 2, is the radius height of the curved surface shaping part in the optical axis direction; is the Zernike polynomial part, are the Zernike polynomial coefficients, are the Zernike polynomial terms, is the number of terms in the Zernike polynomial, is the normalized value of the incident height of the chief ray at the aperture stop for different fields of view, = r / (D / 2), D is the entrance pupil diameter, is the argument angle.

[0054] Specifically, the Smile shape of the bar 1 to be shaped is curved, and its shape is as follows: Figure 6 Since the fast axis divergence angle of the bar is large and the light intensity is Gaussian, the Smile effect also greatly affects the beam quality. Therefore, this embodiment uses a curved shaping element 2 to actively control the beam characteristics of the bar to be shaped 1 in the direction perpendicular to the semiconductor junction plane (i.e., the fast axis direction) to solve its inherent large divergence angle and Gaussian distribution problems. Figure 9 In this embodiment, the standard Zernike polynomial form described in formula (1) is used to linearly fit the free surface 21 of the surface shaping member 2 and make its wave aberration meet the preset value. If the fitting result does not meet the preset value, the curvature of the base part of the surface of the surface shaping member 2 in the Zernike polynomial (1) is changed. and the cone coefficient Repeated simulation and correction are performed to ensure that the fitting result meets the preset value requirements. Based on the curved surface shaping element 2 that meets the requirements after fitting, the light beam in the fast axis direction of the bar to be shaped 1 is shaped. Here, a free-form surface refers to an optical surface with an arbitrary curvature combination.

[0055] In specific implementation, the curvature of the curved surface base portion of the curved surface shaping member 2 in the Zernike polynomial (1) is determined according to the fast axis divergence angle of the bar 1 to be shaped. and entrance pupil diameter D. Preferably, the fast axis divergence angle of the curved shaping piece is , the entrance pupil diameter is D, then according to Calculating curvature ,in, is the device focal length, is the curvature; according to , according to the curvature , entrance pupil diameter D and fast axis divergence angle The relationship between and is used to calculate the entrance pupil diameter D. In formula (1), the cone coefficient It is set by yourself.

[0056] Furthermore, in step S100, the spherical aberration coefficient and the coma coefficient of the Zernike polynomial are adjusted according to the Smile value and Smile shape of the bar 1 to be shaped. In the Zernike polynomial part of formula (1), the eighth term The ninth term is the coma term that affects the edge softening factor of the spot (edge ​​softening factor SEA: the ratio of the width between 90% and 10% of the maximum laser energy density to the corresponding laser beam aperture size). The spherical aberration term affects the uniformity of the light spot. Therefore, in this embodiment, the first 9 terms are selected from the Zernike polynomials. Omitting the calculation of the remaining terms can greatly save calculation time and reduce the difficulty of surface processing. In order to make the single bar 1 to be shaped into a flat-top beam after being shaped by the free surface 21 of the surface shaping member 2, it is necessary to control the spherical aberration value of different normalized entrance pupil diameters, that is, the ninth term. The coefficient of (When the coefficient is 0, it means that no spherical aberration is generated, but at this time it is necessary to deliberately introduce appropriate spherical aberration to make the illumination uniform after shaping), and at the same time control the eighth item Coefficient of off-axis coma value To obtain a lower edge softening factor ( When it is 0, it means no coma is generated. However, if it is applied to the stacking of bars, it is necessary to deliberately introduce appropriate coma to prevent the overlapping part of two adjacent bars to be shaped from generating spikes after shaping.

[0057] Optionally, the eighth coefficient of the Zernike polynomial in formula (1) is adjusted according to the specific value and shape of the Smile of the bar 1 to be shaped. , so that the coefficient of the coma term The second preset range is 0.00001 to 0.005, so that the edge softening factor of the bar to be shaped after being shaped by the curved surface shaping member is within the third preset range, and the third preset range is "edge softening factor less than 5%"; the ninth coefficient of the Zernike polynomial part in formula (1) is adjusted. , so that the coefficient of the spherical aberration term The first preset range is 0.01 to 0.05, so that the spot uniformity of the bar to be shaped after being shaped by the curved surface shaping member is within the fourth preset range, and the fourth preset range is "spot uniformity>95%". This application adjusts the eighth coefficient of the Zernike polynomial and the ninth coefficient , to weaken or eliminate the impact of the Smile effect on the bar to be reshaped.

[0058] Optionally, the Smile value of the bar to be shaped 1 is 5 to 20. Therefore, this embodiment can solve the beam shaping problem of a bar laser with a large Smile value.

[0059] Furthermore, the design of the free-form surface 21 of the curved surface shaping member 2 is performed using computer software to assist in calculation and fitting, and the fitting effect is verified by using the simulated numerical value of wave aberration. Wave aberration is the aberration introduced by the surface error. According to the vector wave aberration theory, the wave aberration of the optical system is the sum of the contributions of the wave aberration of each independent surface. Therefore, the aberration introduced by the eighth and ninth terms in the Zernike polynomial (1) of the single curved surface shaping member 2 can be expressed as the following formula (2):

[0060] (2)

[0061] In formula (2), W is the wavefront aberration of the surface shaping component after adjusting the eighth and ninth coefficients of the Zernike polynomial, and its unit is ; is the refractive index, is the number of luminous points of the bar 1 to be shaped, is the normalized value of the incident height of the principal ray of the curved surface shaping component at the aperture stop in different fields of view; 、 is the coefficient, which has the same meaning as the coefficient of the Zernike polynomial. for , for .

[0062] Furthermore, in step S100, the coefficients of the different Zernike polynomials correspond to different surface shapes and wave aberrations. In this embodiment, by fitting, the wave aberration of the surface shaping element 2 is made smaller than a preset value, and the preset value is 0.89λ, where λ is the calibration wavelength of the surface shaping element, and the unit is In this embodiment, preferably, λ=0.633 The preset value is derived based on the redundancy (tolerance) of the spherical aberration coefficient and the coma coefficient of the Zernike polynomial. When the wavefront aberration fitted by the curved shaping element 2 meets the preset value, the square light spot emitted by the bar to be shaped 1 after shaping has a uniform light intensity distribution and sharp edges.

[0063] Preferably, the base of the curved surface shaping member 2 is made of quartz glass.

[0064] Preferably, the size of the curved surface shaping member 2 is designed according to the size of the bar to be shaped 1, specifically satisfying the following: the length of the curved surface shaping member 2 is greater than the length of the bar to be shaped 1, and the cylindrical height of the curved surface shaping member 2 is designed based on the fast axis divergence angle of the bar to be shaped 1. The cross-sectional profile of the curved surface shaping member 2 is shown in FIG. Figure 7 As shown, the overall structure diagram is as follows Figure 8 shown.

[0065] Based on the laser beam shaping method provided in the first aspect of this embodiment, the second aspect of this embodiment further provides a laser beam shaping system, such as Figure 9 As shown, specifically including:

[0066] A stacked laser array includes a plurality of bars 1 to be shaped arranged along a first direction, wherein the first direction is perpendicular to the arrangement direction of the plurality of single-tube laser chips in the bars 1 to be shaped;

[0067] The curved surface shaping member 2 includes a free-form surface 21 and an incident plane 22. The curved surface shaping member 2 is arranged in the light-emitting direction of the bar 1 to be shaped, wherein the free-form surface 21 is located on the side away from the bar 1 to be shaped, and the incident plane 22 is located on the side close to the bar 1 to be shaped. The first direction and the light-emitting direction are perpendicular to each other.

[0068] Preferably, the horizontal distance between the curved surface shaping member 2 and the bar to be shaped 1 is equal to the focal length of the curved surface shaping member 2 .

[0069] Specifically, the bars 1 to be shaped of the stacked laser array are arranged vertically, and the curved surface shaping members 2 are arranged in one-to-one correspondence with the bars 1 to be shaped.

[0070] Optionally, the wavelength of a single bar 1 to be shaped may be 700-1000 nm, the number of light emitting points of each bar may be 10-65 points, the bar length may be 10 mm, the fast axis divergence angle may be 50-70°, and the slow axis divergence angle may be 8-15°.

[0071] Optionally, the spacing between the bars 1 to be shaped along the first direction may be 0.5 mm to 5 mm, and the spacing between the curved surface shaping members 2 along the first direction may be 0.5 mm to 5 mm.

[0072] Example 1

[0073] Based on the laser beam shaping method and system provided in the above specific implementation manner, this embodiment provides a specific example of beam shaping of a stacked array laser, and repeated parts are not repeated here.

[0074] In this embodiment, the stacked laser array consists of five bars 1 to be shaped, distributed along a first direction perpendicular to the arrangement of the multiple single-tube laser chips in the bars 1. The wavelength of the bars 1 to be shaped is 808 nm, each bar 1 has 10 light-emitting points, a bar length of 10 mm, a fast-axis divergence angle of 70°, a slow-axis divergence angle of 10°, a spacing of 1.5 mm between the bars 1 along the first direction, and a Smile value of 10 for each bar 1. Each bar 1 is curved. A curved surface shaping element 2 is installed perpendicular to the plane of the light source and extending along the X-axis to shape the beam. The curved surface shaping element 2 has a base made of quartz glass and measures 1mm*0.5mm*12mm.

[0075] Based on the above Smile value of 10 The curved surface shaping part 2 is designed based on the bar 1 to be shaped, and the eighth coefficient of the Zernike polynomial part described in formula (1) is adjusted. The ninth coefficient is 0.000273. is 0.01477, and the free curved surface 21 of the curved surface shaping member 2 is fitted. The curvature radius of the curved surface shaping member 2 is -0.48; the focal length is 0.6 mm; = 10 (the number of light-emitting points of the bar to be shaped is 10), the number of single-tube laser chips in a single bar to be shaped is 10, and one single-tube laser chip represents one light-emitting point. The curved surface shaping element 2 shapes the beams emitted by the 10 light-emitting points. The curved surface shaping element 2 includes parts that shape the beams emitted by the 10 light-emitting points respectively. At this time, after the curved surface shaping element 2 with the above parameters shapes the beam of the single bar to be shaped 1, the light spot of the single bar to be shaped 1 is as follows Figure 10 As shown, the fast axis light intensity distribution is Figure 11 shown.

[0076] A collimated beam is used to test the curved surface shaping member 2, with wave aberrations such as partial defocus, spherical aberration and coma. Figure 12 As shown, the wavefront aberration value is calculated based on the aforementioned formula (2) to obtain W=0.67λ, which meets the aforementioned preset value requirements.

[0077] The curved surface shaping element 2 is applied to the stacked laser array consisting of 5 bars 1 to be shaped. The overall optical path diagram is as follows: Figure 13 As shown, the spot after shaping is as follows Figure 14 As shown, the fast axis light intensity distribution curve is as follows Figure 15 As shown in the figure, the spot uniformity is >95%, the edge softening factor is <5%, and only one set of optical shaping devices is used. Figure 16, the light intensity distribution is as follows Figure 17 Existing solutions are significantly affected by Smile, resulting in severe shadowing at both ends of the beam spot. Uniformity is also poor, less than 80%, and the edge softening factor is large, exceeding 15%. Therefore, this comparison demonstrates the significant improvements in both beam uniformity and edge softening factor achieved by the design proposed in this embodiment for stacked laser arrays.

[0078] The embodiments of the present invention achieve the following technical effects:

[0079] 1. This application addresses the Smile effect of a bar-shaped laser array. By fitting the free-form surface of a curved shaping element with Zernike polynomials, the spherical aberration and coma of different normalized entrance pupil diameters are adjusted by adjusting the micro-curvature of the free-form surface of the curved shaping element. This weakens or eliminates the Smile effect of the bar-shaped laser array, resulting in a uniform light intensity distribution and sharp edges on the square spot after shaping, a small edge softening factor, and high spot uniformity.

[0080] 2. The spot shaping method provided in this application has the advantages of high beam quality, controllable spot size, simple shaping method, easy implementation, cost reduction, small size of optical shaping system, and compact structure. One-time shaping can meet the spot distribution requirements and beam quality requirements of the stacked array laser. It has low cost and low process difficulty, and can be used in scientific research and medical industries.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A laser beam shaping method, characterized in that: The laser includes a bar to be shaped and a curved surface shaping member arranged corresponding to the bar to be shaped. The method includes: According to the Smile feature of the bar to be shaped, the spherical aberration coefficient and the coma coefficient of the Zernike polynomial of the curved surface shaping component are adjusted to be within a first preset range and a second preset range, respectively. The first preset range and the second preset range are determined based on the Smile feature of the bar to be shaped, respectively. According to the adjusted Zernike polynomial, the free-form surface of the curved surface shaping component is fitted so that the wavefront aberration of the curved surface shaping component after fitting is less than a preset value. The simulated numerical value of the wavefront aberration is expressed as: Wherein, W is the wavefront aberration of the surface shaping element after adjusting the spherical aberration coefficient and the coma coefficient of the Zernike polynomial, and the unit is ; is the refractive index, is the number of luminous points of the bar to be shaped, is the normalized value of the incident height of the principal ray of the curved surface shaping component at the aperture stop in different fields of view; 、 is the coefficient, which has the same meaning as the coefficient of the Zernike polynomial. for , For A8; The determined curved surface shaping member is set in the light-emitting direction of the bar to be shaped, and the curved surface shaping member is used to shape the light beam in the fast axis direction of the bar to be shaped.

2. The laser beam shaping method according to claim 1, characterized in that: After fitting, the wave aberration simulation value of the curved surface shaping component is less than the preset value, and the preset value is 0.89λ, where λ is the calibration wavelength of the curved surface shaping component, and the unit is .

3. The laser beam shaping method according to claim 1, characterized in that: The Zernike polynomials are: in, is the optical surface sagittal height, is the curved surface base portion of the curved surface shaping member, wherein, is the cone coefficient, is the curvature of the free-form surface of the curved surface shaping part, is the radius height of the curved surface shaping member in the optical axis direction; is the Zernike polynomial part, are the Zernike polynomial coefficients, are the Zernike polynomial terms, is the number of terms in the Zernike polynomial, is the normalized value of the incident height of the chief ray at the aperture stop for different fields of view, =r / (D / 2), D is the entrance pupil diameter, is the argument angle.

4. The laser beam shaping method according to claim 3, characterized in that: Adjust the coefficient of the eighth term of the Zernike polynomial part so that the edge softening factor of the bar to be shaped after shaping by the curved surface shaping member is within the third preset range, that is, adjust the coefficient of the coma term It is between 0.00001 and 0.

005.

5. The laser beam shaping method according to claim 3, characterized in that: Adjust the coefficient of the ninth term of the Zernike polynomial so that the spot uniformity of the bar to be shaped after being shaped by the curved surface shaping member is within the fourth preset range, that is, adjust the coefficient of the spherical aberration term Between 0.01 and 0.

05.

6. The laser beam shaping method according to claim 3, characterized in that: According to the fast axis divergence angle of the bar to be shaped, the curvature of the surface base of the surface shaping piece of the Zernike polynomial is determined. , entrance pupil diameter D and cone coefficient .

7. The laser beam shaping method according to claim 1, characterized in that: The Smile value of the bar to be shaped is 5~20. .

8. The laser beam shaping method according to claim 1, characterized in that: The base of the curved surface shaping piece is quartz glass.

9. A laser beam shaping system, characterized in that: The system is applied to the method according to any one of claims 1 to 8, comprising: A stacked laser array includes a plurality of bars to be shaped arranged along a first direction, wherein the first direction is perpendicular to the arrangement direction of the plurality of single-tube laser chips in the bars to be shaped; A curved surface shaping member is provided in the light-emitting direction of the bar to be shaped, and includes a free curved surface and an incident plane. The free curved surface is located on a side away from the bar to be shaped; the incident plane is located on a side close to the bar to be shaped.

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