Light beam conversion device and optical processing equipment

Abstract

The invention provides a light beam conversion device and optical processing equipment, the light beam conversion device is used for carrying out light beam conversion on a first light beam, and the light beam conversion device comprises a diffraction optical module and a refraction optical module which are arranged along the optical axis of the first light beam; the diffractive optical module and the refractive optical module are used for carrying out light beam conversion on the first light beam together and outputting a second light beam, the light intensity distribution of the second light beam in the first direction is flat-topped distribution, the light intensity distribution of the second light beam in the second direction is Gaussian distribution, and the first direction and the second direction are both perpendicular to the optical axis; and the first direction is perpendicular to the second direction. According to the light beam conversion device, the light beams are accurately converted through the synergistic effect of the diffraction optical module and the refraction optical module, so that the light intensity distribution of the second light beam in the first direction reaches flat-top distribution, and the light intensity distribution of the second light beam in the second direction is kept Gaussian distribution, and due to the fact that the light beam conversion device only uses the diffraction optical module and the refraction optical module, the light intensity distribution of the second light beam is uniform. Therefore, installation and adjustment are simpler.

Description

Technical Field

[0001] The present application relates to the field of optics, and in particular to a light beam conversion device and optical processing equipment. Background Art

[0002] In the field of optics, beam transformation technology has always been a hot topic and focus of research. With the continuous development of science and technology, the demand for precise control of the shape, intensity distribution and transmission characteristics of the beam is increasing. Especially in the fields of laser processing, optical measurement, optical communication and optical imaging, it is particularly important to accurately transform the beam to achieve specific functions.

[0003] In the prior art, in order to achieve the transformation of light beams, a complex optical system is usually required, including multiple optical elements such as lenses, reflectors, gratings, etc. Although the combination of these optical elements can achieve the transformation of light beams to a certain extent, they often have complex structures, which makes installation and adjustment difficult. Summary of the invention

[0004] The present application provides a light beam conversion device and an optical processing device, which are used to solve the problem of difficult assembly and adjustment of optical components.

[0005] In the first aspect, an embodiment of the present application provides a beam transformation device for transforming a first light beam, the beam transformation device includes a diffraction optical module and a refraction optical module arranged in an optical path, the diffraction optical module and the refraction optical module are used to jointly transform the first light beam and output a second light beam, wherein the light intensity distribution of the second light beam in the first direction is a flat-top distribution, and the light intensity distribution of the second light beam in the second direction is a Gaussian distribution, the first direction and the second direction are both perpendicular to the optical axis of the second light beam, and the first direction is perpendicular to the second direction. In the embodiment of the present application, the precise transformation of the light beam is achieved through the synergistic effect of the diffraction optical module and the refraction optical module, so that the light intensity distribution of the second light beam in the first direction reaches a flat-top distribution, while in the second direction it maintains a Gaussian distribution. Since this beam transformation device only uses the diffraction optical module and the refraction optical module, the assembly and adjustment are simpler, thereby improving the assembly efficiency of the beam transformation device.

[0006] In a possible implementation, the diffraction optical module is located before the refractive optical module, and the diffraction optical module is used to shape the first light beam in a first direction and output a flat-top beam to the refractive optical module. Furthermore, the refractive optical module is used to focus the flat-top beam in a second direction and output a second light beam. In an embodiment of the present application, the diffraction optical module is disposed before the refractive optical module, and the diffraction optical module is used to shape the first light beam in the first direction, and the first light beam is converted into a flat-top beam, which then enters the refractive optical module, and the refractive optical module uses the refraction effect to focus the flat-top beam in the second direction. Therefore, through the synergistic effect of the diffraction optical module and the refractive optical module, the separation of the light beam modulation function in two directions is achieved, which can significantly improve the performance, flexibility and design freedom of the optical system.

[0007] In a possible implementation, the refractive optical module is located in front of the diffractive optical module, and the refractive optical module is used to focus the first light beam in the second direction and output the focused light beam to the diffractive optical module. Furthermore, the diffractive optical module is used to shape the focused light beam in the first direction and output the second light beam. In the embodiment of the present application, the refractive optical module can be used to realize beam focusing of the second light beam in the second direction, and the diffractive optical module can be used to realize beam shaping of the second light beam in the first direction, which can significantly improve the performance, flexibility and design freedom of the optical system.

[0008] In a possible implementation, when the diffractive optical module is located before the refractive optical module, the diffractive optical module is arranged at the waist position of the first light beam; when the refractive optical module is located before the diffractive optical module, the diffractive optical module is arranged at the waist position of the focused light beam. In the embodiment of the present application, since the waist position of the light beam is the narrowest position of the light beam, the cross-sectional size of the light beam is relatively small, and the light energy density is high, placing the diffractive optical module at this position can reduce the loss of light energy during propagation and improve the utilization rate of light energy, and can reduce the size of the diffractive optical module on the one hand.

[0009] In a possible implementation, the refractive optical module has a curved surface. When the diffractive optical module is located before the refractive optical module, the curved surface faces the incident direction of the flat-top beam. When the refractive optical module is located before the diffractive optical module, the curved surface faces the incident direction of the first light beam. In the embodiment of the present application, the curved surface design can compensate for the aberrations (such as spherical aberration, chromatic aberration, etc.) generated by the light beam during propagation. When the curved surface faces the incident direction of the flat-top beam or the first light beam, it can ensure that more light beam energy is effectively captured and refracted, thereby improving the utilization rate of the light beam.

[0010] In a possible implementation, the diffraction optical module is a multi-step diffraction optical module. In the embodiment of the present application, the diffraction optical module modulates the light beam through the diffraction structure on its surface, so that the light wave bends and disperses during the propagation process. When the number of steps increases, these diffraction structures can more finely regulate the phase distribution of the light wave, so that the light wave can propagate more accurately according to the designed path and intensity distribution, thereby reducing light energy loss and stray light, and thus improving diffraction efficiency.

[0011] In a possible implementation, the number of steps of the multi-step diffraction optical module is not less than 4. In the embodiment of the present application, the number of steps is set to be not less than 4, because more incident light is effectively diffracted to the target direction, thereby improving the diffraction efficiency of the light beam.

[0012] In a possible implementation, the diffractive optical module has an incident surface and an exit surface, wherein at least one of the incident surface and the exit surface is coated with an anti-reflection film. In the embodiment of the present application, when light passes through the diffractive optical module, the reflected light of at least one of the incident surface and the exit surface can be reduced or eliminated, thereby increasing the light transmittance of the diffractive optical module to reduce or eliminate the stray light of the light beam, thereby improving the light transmittance performance of the entire light beam conversion device.

[0013] In a possible implementation, when the refractive optical module includes a plurality of refractive optical elements, and each of the refractive optical elements has a curved surface, the generatrix directions of the curved surfaces (i.e., the plurality of curved surfaces) of the plurality of refractive optical elements are the same. In this embodiment of the present application, the aberration of the incident light beam (such as the flat-top light beam or the first light beam) of the refractive optical module can be corrected, and the beam width of the second light beam in the second direction can be compressed, thereby outputting a thinner and narrower second light beam, thereby improving the spot quality of the second light beam.

[0014] In a possible implementation, the best position for homogenizing the second light beam coincides with the focal position of the refractive optical module. In the embodiment of the present application, by aligning the best position for shaping the second light beam with the focal position of the refractive optical module, the line width of the second light beam can be made as small as possible, while achieving the best homogenization effect of the second light beam.

[0015] In a possible implementation, the distance between the diffractive optical module and the refractive optical module is greater than or equal to 10 mm. In the embodiment of the present application, by maintaining a sufficient distance (greater than or equal to 10 mm) between the diffractive optical module and the refractive optical module, a larger operating space is provided for the assembly and adjustment process, which helps operators to more easily install, align and adjust the two modules, ensuring that the relative position and angle between them meet the design requirements, thereby improving assembly efficiency and adjustment accuracy.

[0016] In a possible implementation, the aspect ratio of the second light beam in the target plane is 10: 1. In the embodiment of the present application, the second light beam with an aspect ratio of 10: 1 can provide higher precision processing, thereby improving the processing accuracy.

[0017] In a possible implementation, the distance from the center of the refractive optical module to the center of the target plane along the optical axis is the same as the focal length of the refractive optical module. In the embodiment of the present application, since the light beam reaches the minimum spot size at the focal position, the distance from the center of the refractive optical module to the target plane is set as the focal length, which can ensure that the narrowest second light beam is obtained on the target plane, thereby improving the energy density of the light beam.

[0018] In a possible implementation, the target plane is perpendicular to the optical axis of the second light beam, and the target plane is a vertical plane. Optionally, the angle between the target plane and the optical axis of the second light beam is between (0°, 90°), and the target plane is an inclined plane. In the embodiment of the present application, for a vertical plane, the energy of the light beam is concentrated at the center of the light spot, which is suitable for applications requiring high energy density; for an inclined plane, the energy of the light beam can be distributed along a specific direction, which is suitable for applications requiring a specific energy distribution. Whether it is a vertical plane or an inclined plane, by precisely controlling the relationship between the target plane and the optical axis of the second light beam, the energy distribution of the light beam on the target plane can be optimized, thereby improving the utilization rate of the light beam.

[0019] In a second aspect, an embodiment of the present application provides an optical processing device, which includes a light beam transformation device as provided in the first aspect and any one of its possible implementations. In an embodiment of the present application, since the light beam transformation device is integrated in the optical processing device, the device can accurately control and adjust the shape, size and direction of the light beam, so that the optical processing device can perform high-precision and high-stability optical processing.

[0020] It should be understood that the implementation and beneficial effects of the above-mentioned aspects of the present application can be referenced to each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a structural schematic diagram of a light beam conversion device provided in an embodiment of the present application;

[0022] Figure 2 is a three-dimensional distribution diagram of the second light beam provided in an embodiment of the present application;

[0023] Figure 3 is another structural schematic diagram of the light beam conversion device provided in an embodiment of the present application;

[0024] Figure 4A It is a one-dimensional surface schematic diagram of a 16-step diffractive optical module provided in an embodiment of the present application;

[0025] Figure 4B is a schematic structural diagram of the diffraction structure surface in the incident surface and the exit surface provided in the embodiment of the present application;

[0026] Figure 5 is a schematic diagram of performing beam fitting on a beam transformation device provided in an embodiment of the present application;

[0027] Figure 6 It is a structural schematic diagram when the light beam conversion device provided in an embodiment of the present application outputs a second light beam to a target plane and the target plane is perpendicular to the optical axis of the second light beam;

[0028] Figure 7 is another structural schematic diagram when the light beam conversion device provided in an embodiment of the present application outputs a second light beam to a target plane and the target plane is perpendicular to the optical axis of the second light beam;

[0029] Figure 8 is a schematic diagram of a second light beam on a target plane provided by an embodiment of the present application;

[0030] Fig. 9 is another schematic diagram of the second light beam on the target plane provided by an embodiment of the present application;

[0031] Fig.10 is a schematic diagram of another length X-ray intensity I of the second light beam in the first direction provided by an embodiment of the present application;

[0032] Fig.11 It is a structural schematic diagram when the light beam conversion device provided in an embodiment of the present application outputs a second light beam to a target plane and the angle between the target plane and the optical axis of the second light beam is between (0°, 90°);

[0033] Fig.12 is another structural schematic diagram when the light beam conversion device provided in an embodiment of the present application outputs a second light beam to a target plane and the angle between the target plane and the optical axis of the second light beam is between (0°, 90°);

[0034] Fig.13 is another schematic diagram of the second light beam on the target plane provided by an embodiment of the present application;

[0035] Fig.14 is a schematic diagram of another length X-ray intensity I of the second light beam in the first direction provided by an embodiment of the present application;

[0036] Fig.15 It is a schematic diagram of the structure of the optical processing equipment provided in the embodiment of the present application.

[0037] Description of reference numerals:

[0038] 10- beam conversion device;

[0039] 101-diffraction optical module; 102-refractive optical module;

[0040] 1011-incident surface; 1012-exit surface; 1021-curved surface;

[0041] 20-target plane;

[0042] 30- Optical processing equipment; DETAILED DESCRIPTION

[0043] Beam conversion devices are mainly used in typical scenarios such as laser processing, laser detection, laser lighting (such as dark field microscope lighting), semiconductor detection, microscopic imaging, optical measurement and optical communication. Beam conversion devices are usually integrated into optical processing equipment (such as laser cutting machines, laser welding machines, etc.), microscopic imaging systems and optical measurement systems. They exist in the form of focusing mirrors, beam expanders, beam splitters and diffraction optical modules to finely shape and control the laser beam. The beam conversion device is closely connected to other optical components such as lasers, reflectors, focusing mirrors, beam expanders and beam splitters. Taking optical processing equipment as an example, the beam conversion device receives the original light beam emitted by the laser, and through a series of shaping and control processes, it transmits the optimized light beam to components such as reflectors and focusing mirrors, and finally acts accurately on the processed material.

[0044] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] The terms "first" and "second" in the description and claims of the embodiments of the present application are used to distinguish different objects rather than to describe a specific order of objects. For example, a first target object and a second target object are used to distinguish different target objects rather than to describe a specific order of target objects.

[0046] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0047] In the description of the embodiments of the present application, unless otherwise specified, the meaning of "multiple" refers to two or more than two. For example, multiple processing units refer to two or more processing units; multiple systems refer to two or more systems.

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly, in detail and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] Embodiment 1

[0050] Figure 1 Schematic diagram of a structure of a light beam conversion device provided in an embodiment of the present application. Figure 1 As shown, the beam transformation device 10 is used to transform the first beam, wherein the beam transformation device 10 includes a diffraction optical module 101 and a refraction optical module 102 arranged in the optical path. The diffraction optical module 101 and the refraction optical module 102 are used to jointly transform the first beam and output a second beam. Exemplarily, the three-dimensional distribution diagram of the second beam can be as follows: Figure 2 As shown, the light intensity distribution of the second light beam in the first direction is a flat-top distribution, and the light intensity distribution of the second light beam in the second direction is a Gaussian distribution. The first direction and the second direction are both perpendicular to the optical axis of the second light beam, and the first direction is perpendicular to the second direction.

[0051] In the embodiment of the present application, the beam transformation is to shape and focus the beam, and the diffraction optical module 101 is used to shape the first beam, that is, to shape the first beam into a flat-top beam in the first direction, wherein the flat-top beam is a beam with uniform intensity of the entire spot, sharp edges, and energy outside the spot area rapidly drops to zero. The refraction optical module 102 is used to focus the first beam, that is, to focus the first beam in the second direction into a Gaussian beam, wherein the Gaussian beam is a beam whose light intensity gradually decreases from the center to the outside, and the speed of decrease conforms to the law of the Gaussian function.

[0052] The first direction and the second direction are both perpendicular to the optical axis of the second light beam, and the optical axis of the second light beam is perpendicular to the plane where the first direction and the second direction are located, wherein the first direction and the second direction are located in different directions of the above plane, and the first direction and the second direction are perpendicular to each other.

[0053] The diffraction optical module 101 is an optical module that uses the diffraction optical principle to modulate the amplitude or phase of its incident light beam. Specifically, the diffraction optical module 101 can achieve high-frequency phase modulation of the incident light beam (such as the first light beam), and the high-frequency phase modulation of the incident light beam can be equivalent to the coherent superposition of multiple incident light beams, so that the output light beam can achieve a better homogenization effect, thereby improving the spot quality of the second light beam.

[0054] In some embodiments of the present application, the diffraction optical module 101 can be a flat-top beam generator, which converts the first light beam (near-Gaussian incident light) into a circular, rectangular, square, linear or other shaped output light spot with uniform intensity on a specific plane. The diffraction optical module 101 may include one or more diffraction optical elements, and the diffraction optical module 101 includes a diffraction optical element as an example for explanation. The diffraction optical element usually uses a micro-nano etching process to form a two-dimensionally distributed diffraction unit (such as a grating, a relief pattern, etc.). These diffraction units are arranged on the surface of the element in a specific manner, and each diffraction unit has specific morphology, refractive index and other characteristics, and can finely control the laser wavefront phase distribution. Specifically, the surface microstructure of the diffraction optical element is composed of a series of tiny diffraction units. These diffraction units can be of various shapes, such as sawtooth, curved surface, etc., and their period and shape will vary according to design requirements. For example, the diffraction lattice may present a concentric circle structure, and the lattice period gradually decreases from the inside to the outside.

[0055] In some embodiments of the present application, the diffraction unit of the diffraction optical element can be a single-layer structure. By accurately designing the pattern and depth of the single-layer diffraction unit, the first light beam can be effectively diffracted and shaped to meet specific application requirements. The diffraction unit of the diffraction optical element can also be designed as a multi-layer structure. The simultaneous action of the multi-layer diffraction unit enables the light beam to be modulated multiple times during the propagation process, and the phase and amplitude of the light can be more finely controlled, thereby obtaining a more ideal light intensity distribution and beam shape. Specifically, the diffraction optical module 101 includes a light incident surface and a light exit surface, and the light beam is incident vertically or obliquely to the light incident surface. If the diffraction unit of the diffraction optical module is a single-layer structure, the single-layer diffraction unit can be located on one of the light incident surface and the light exit surface, or in a structure between the light incident surface and the light exit surface. If the diffraction unit of the diffraction optical module is a multi-layer structure, the multi-layer diffraction unit can be located on the light incident surface and the light exit surface at the same time, or in a structure between the light incident surface and the light exit surface.

[0056] In some embodiments of the present application, the diffractive optical module 101 is a transmissive optical module or a reflective optical module, and the optical axis of the diffractive optical module 101 may be collinear with the optical axis of the refractive optical module 102, or may not be collinear. When no optical element (such as a reflector) for changing the transmission direction of the light beam is provided between the diffractive optical module 101 and the refractive optical module 102, the optical axis of the diffractive optical module 101 is collinear with the optical axis of the refractive optical module 102; when an optical element for changing the transmission direction of the light beam is provided between the diffractive optical module 101 and the refractive optical module 102, the optical axis of the diffractive optical module 101 is not collinear with the optical axis of the refractive optical module 102. When the diffractive optical module 101 is a reflective optical module, the optical axis of the diffractive optical module 101 is not collinear with the optical axis of the refractive optical module 102.

[0057] In some embodiments of the present application, the diffraction optical module 101 may include a divergent diffraction element and a convergent diffraction element. The divergent diffraction element is located between the collimating lens and the convergent diffraction element, and is used to make the light beam diverge along a first direction, while remaining unchanged along a second direction perpendicular to the first direction. The convergent diffraction element is used to make the divergent light beam converge along the first direction, while also keeping the second direction unchanged, thereby obtaining a flat-top beam. By cleverly arranging a divergent diffraction element between the collimating lens and the convergent diffraction element, the light beam can be diffused in a predetermined manner, while maintaining stable transmission characteristics in a second direction perpendicular to the first direction. Subsequently, the convergent diffraction element further accurately converges the divergent light beam to ensure that the light beam is refocused in the first direction while keeping the light beam characteristics in the second direction unchanged. In this process, the energy distribution of the light beam is precisely controlled, and a flat-top beam is finally formed, which can achieve precise shaping and high-quality output of the light beam.

[0058] The above-mentioned refractive optical module 102 is an optical module that focuses its incident light beam using the principle of refraction, and the refractive optical module 102 may include one or more refractive optical elements. Exemplarily, the refractive optical element may be one of a cylindrical mirror and a spherical mirror. Taking the refractive optical module 102 including a refractive optical element, and the refractive optical element being a cylindrical mirror as an example, the refractive optical module 102 includes a curved surface 1021, wherein the curved surface is a trajectory plane formed by a moving line (such as a straight line or a curve) continuously moving in space, and this moving line may be referred to as the generatrix of the curved surface 1021. The above is only an example, and this embodiment does not limit the specific structure of the diffractive optical module 101 and the refractive optical module 102.

[0059] In the embodiment of the present application, precise transformation of the light beam is achieved through the coordinated action of the diffraction optical module 101 and the refraction optical module 102, so that the light intensity distribution of the second light beam in the first direction reaches a flat-top distribution, while maintaining a Gaussian distribution in the second direction. Since this light beam transformation device 10 only uses the diffraction optical module 101 and the refraction optical module 102, the installation and adjustment are simpler, thereby improving the assembly efficiency of the light beam transformation device 10.

[0060] In some embodiments of the present application, when the diffractive optical module 101 is located before the refractive optical module 102, the structure of the beam transformation device 10 can be as follows: Figure 1 As shown, the diffraction optical module 101 is used to shape the first light beam in the first direction and output a top-hat light beam to the refractive optical module 102. The first light beam can be provided by an external light source, and illustratively, the first light beam can be a Gaussian light beam. Further, the refractive optical module 102 is used to focus the top-hat light beam in the second direction and output a second light beam.

[0061] It can be understood that shaping aims to control the incident light beam through diffraction optical components, mainly changing the intensity distribution of the light beam. Focusing aims to obtain a high-energy-density light spot through refractive optical components to achieve the concentration and amplification of light energy.

[0062] Specifically, the diffraction optical module 101 is located before the refractive optical module 102, which means that the first light beam is first incident on the diffraction optical module 101, and then the light beam output from the diffraction optical module 101 is incident on the refractive optical module 102. Specifically, the first light beam first passes through the diffraction optical module 101, and is shaped into a flat-top beam in the first direction after being regulated by the diffraction element. In this process, the energy distribution of the light beam is redistributed, so that the light beam presents a flat-top shape in the cross section. The shaped flat-top beam then enters the refractive optical module 102, and is focused in the second direction through the refraction effect of the lens group. The focused second light beam has a higher energy density and a smaller spot size.

[0063] In implementing the embodiment of the present application, the diffraction optical module 101 is arranged in front of the refractive optical module 102, and the diffraction optical module 101 is used to shape the first light beam in the first direction, and the first light beam is converted into a flat-top beam. The flat-top beam then enters the refractive optical module 102, and the refractive optical module 102 uses the refraction effect to focus the flat-top beam in the second direction. Therefore, through the synergistic effect of the diffraction optical module 101 and the refractive optical module 102, the separation of the light beam modulation functions in two directions is achieved, which can significantly improve the performance, flexibility and design freedom of the optical system.

[0064] In some embodiments of the present application, when the refractive optical module 102 is located before the diffractive optical module 101, the structure of the beam transformation device 10 is as follows: Figure 3 As shown, the refractive optical module 102 is used to focus the first light beam in the second direction and output the focused light beam to the diffractive optical module 101. Further, the diffractive optical module 101 is used to shape the focused light beam in the first direction and output the second light beam.

[0065] Specifically, the refractive optical module 102 is used to focus the incident first light beam in the second direction. By accurately designing the parameters such as the lens shape, material and refractive index of the refractive optical module 102, it can be ensured that the first light beam can form a focused light beam in the second direction after passing through the refractive optical module 102. At this time, the focused light beam will serve as the input light of the diffraction optical module 101. Then, the focused light beam enters the diffraction optical module 101, and the diffraction optical module 101 uses the diffraction effect to shape the focused light beam in the first direction. Through carefully designed parameters such as diffraction patterns and line density, the diffraction optical module 101 can change the energy distribution of the focused light beam in the first direction, thereby outputting a second light beam with a specific shape and characteristics, and the second light beam has both a flat top and a Gaussian light intensity distribution.

[0066] By implementing the embodiments of the present application, the refractive optical module 102 can be used to focus the second light beam in the second direction, and the diffractive optical module 101 can be used to shape the second light beam in the first direction, thereby achieving the separation of the light beam modulation functions in two directions, which can significantly improve the performance, flexibility and design freedom of the optical system.

[0067] In some embodiments of the present application, when the diffractive optical module 101 is located before the refractive optical module 102, the diffractive optical module 101 is disposed at the waist position of the first light beam. When the refractive optical module 102 is located before the diffractive optical module 101, the diffractive optical module 101 is disposed at the waist position of the focused light beam.

[0068] It can be understood that the beam waist is the position where the beam diameter reaches the minimum value, which is the turning point of the beam convergence and divergence. The position of the beam waist is the focus or approximate focus position of the beam, where the light intensity reaches the maximum and the divergence angle of the beam is also the smallest. Since the beam diameter is the smallest and the light intensity distribution is the most concentrated at the beam waist position, it is beneficial for the diffractive optical module 101 to accurately control and shape the beam.

[0069] When implementing the embodiment of the present application, since the waist position of the light beam is the narrowest position of the light beam, the cross-sectional size of the light beam is relatively small and the light energy density is high, placing the diffraction optical module 101 at this position can, on the one hand, reduce the loss of light energy during the propagation process and improve the utilization rate of light energy; on the other hand, it can reduce the size of the diffraction optical module 101.

[0070] In some embodiments of the present application, the refractive optical module 102 has a curved surface 1021. When the diffractive optical module 101 is located before the refractive optical module 102, the curved surface 1021 faces the incident direction of the flat-top beam. When the refractive optical module 102 is located before the diffractive optical module 101, the curved surface 1021 faces the incident direction of the first beam.

[0071] Specifically, the curved surface 1021 faces the flat top beam, which means that the curved surface 1021 is directly opposite to the flat top beam, so that it can receive or reflect the flat top beam. The curved surface 1021 faces the first beam, which means that the curved surface 1021 is directly opposite to the first beam, so that it can receive or reflect the first beam.

[0072] In the embodiment of the present application, the curved surface design can compensate for the aberrations (such as spherical aberration, chromatic aberration, etc.) generated during the propagation of the light beam. When the curved surface 1021 faces the incident direction of the flat-top light beam or the first light beam, it can ensure that more light beam energy is effectively captured and refracted, thereby improving the utilization rate of the light beam.

[0073] In some embodiments of the present application, the diffractive optical module 101 may be a multi-step diffractive optical module.

[0074] The specific structure of the multi-step diffraction optical module is mainly composed of multiple steps with different heights or morphologies, which form diffraction units in the form of two-dimensional distribution. Each diffraction unit can have a specific morphology, refractive index, etc., to finely control the phase distribution of the laser wavefront. These steps are made by micro-nano etching technology, usually formed on the surface of the component, so that the laser diffracts after passing through each diffraction unit and interferes at a certain distance (such as infinity or the focal plane of the lens), thereby forming a uniform light intensity distribution in a specific direction.

[0075] Specifically, the step shape of the multi-step diffraction optical module is at least one of a rectangle, a trapezoid, and a triangle.

[0076] In implementing the embodiment of the present application, the diffraction optical module 101 modulates the light beam through the diffraction structure on its surface, causing the light wave to bend and disperse during the propagation process. When the number of steps increases, these diffraction structures can more finely control the phase distribution of the light wave, so that the light wave can propagate more accurately according to the designed path and intensity distribution, thereby reducing light energy loss and stray light, and thus improving the diffraction efficiency.

[0077] In some embodiments of the present application, the number of steps of the multi-step diffraction optical module is not less than 4.

[0078] Specifically, through experimental testing of the diffraction efficiency of the diffraction optical module with different numbers of steps, it can be learned that when the number of steps of the diffraction optical module 101 is 2, the theoretical diffraction efficiency of the diffraction optical module 101 is 41%. When the number of steps of the diffraction optical module 101 is 4, the theoretical diffraction efficiency of the diffraction optical module 101 is 81%. When the number of steps of the diffraction optical module 101 is 8, the theoretical diffraction efficiency of the diffraction optical module 101 is 95%. When the number of steps of the diffraction optical module 101 is 16, the theoretical diffraction efficiency of the diffraction optical module 101 is 99%. Exemplarily, the one-dimensional surface diagram of the diffraction optical module 101 with 16 steps can be as follows: Figure 4A As shown, the total height h1 of the diffractive optical module 101 is 498.89 nm and the step height h2 is 33.26 nm, wherein the structures of the diffractive structure surfaces in the incident surface 1011 and the exit surface 1012 can be as follows: Figure 4B shown.

[0079] From the above, we can see that the number of steps (i.e., the number of phase orders) is positively correlated with the diffraction efficiency. When the number of steps is 2, the diffraction efficiency is 41%, which is a relatively low efficiency value and cannot meet certain application scenarios with high requirements for diffraction efficiency. When the number of steps increases to 4, the diffraction efficiency jumps to 81%, which means that more incident light is effectively diffracted to the target direction. At this time, the diffraction efficiency has also reached a relatively high level and can meet the needs of practical applications.

[0080] In some embodiments of the present application, the diffraction optical module 101 may also be a continuous surface diffraction optical module, which can achieve higher diffraction efficiency, thereby improving the spot quality of the second light beam.

[0081] In some embodiments of the present application, at least one of the incident surface 1011 and the exit surface 1012 is coated with an anti-reflection film.

[0082] Specifically, the anti-reflection film is a thin film material that has light transmittance and can increase light transmittance. If at least one of the incident surface 1011 and the exit surface 1012 has a diffraction structure, a thin film of a transparent medium is coated on at least the surface with the diffraction structure; if the diffraction optical module 101 has a diffraction structure in its structure, at least one of the incident surface 1011 and the exit surface 1012 is coated with an anti-reflection film.

[0083] By implementing the embodiment of the present application, when light passes through the diffractive optical module 101, the reflected light of at least one of the incident surface 1011 and the exit surface 1012 can be reduced or eliminated, thereby increasing the light transmittance of the diffractive optical module 101 to reduce or eliminate the stray light of the light beam, thereby improving the light transmittance performance of the entire light beam conversion device.

[0084] In some embodiments of the present application, the surface shape change direction of the diffraction structure surface in the incident surface 1011 and the exit surface 1012 is perpendicular to the directrix direction of the curved surface 1021, wherein the surface shape change direction is the direction in which the surface shape of the diffraction structure surface changes. By implementing the embodiments of the present application, the beam quality of the second light beam can be improved, thereby improving the beam shaping efficiency of the entire device.

[0085] In some embodiments of the present application, when the refractive optical module 102 includes a plurality of refractive optical elements, and each of the refractive optical elements has a curved surface, the generatrix directions of the curved surfaces (ie, the plurality of curved surfaces) of the plurality of refractive optical elements are the same.

[0086] Specifically, the refractive optical module 102 is composed of a plurality of refractive optical elements, each of which has one or more curved surfaces, which are curved in the same direction, and are located at the incident surface of each refractive optical element, or at the exit surface of each refractive optical element. The direction of the busbar is determined based on the specific requirements of the optical system, such as the incident angle, exit angle, and focusing distance of the light beam. By adjusting the direction of the busbar, the propagation path and focusing characteristics of the light beam can be optimized.

[0087] By implementing the embodiment of the present application, the aberration of the incident light beam (such as the flat-top beam or the first light beam) of the refractive optical module 102 can be corrected, and the beam width of the second light beam in the second direction can be compressed, thereby outputting a thinner and narrower second light beam, thereby improving the spot quality of the second light beam.

[0088] In some embodiments of the present application, the position where the second light beam is best homogenized coincides with the focal position of the refractive optical module 102 .

[0089] It can be understood that the position where the second light beam is best homogenized refers to the position where the energy distribution of the second light beam in the first direction is most uniform, and the focal position of the refractive optical module 102 is the position where the spot size of the second light beam in the second direction is minimum. The overlap of the above two positions can ensure that the maximum homogenization of the light beam and the best focusing effect are achieved at the same position.

[0090] In the embodiment of the present application, optical design software (such as Zemax) can be used to perform beam simulation on the entire beam transformation device 10. When the optical design software is used for simulation, the light source, the diffractive optical module 101, the refractive optical module 102 and the target plane 20 are set first to construct the beam transformation of the beam transformation device 10, and then the positions and parameters of the light source, the diffractive optical module 101, the refractive optical module 102 and the target plane 20 are continuously adjusted to obtain the best homogenization position of the second beam and the coincidence of the focal position of the refractive optical module 102, and finally the best homogenization position of the second beam and the coincidence of the focal position of the refractive optical module 102 are determined by measuring the light spot near the focus of the refractive optical module 102.

[0091] For example, suppose that a second light beam (such as a straight line laser) with a length of 10 mm, a width of 0.5 mm, and uniform light intensity distribution needs to be output. In the optical design software, follow the steps below to perform simulation and design:

[0092] Step 1: Set the light source to a red laser with a wavelength of 635nm and a power of 100mW.

[0093] Step 2: Add a diffraction optical module 101, set the period of its diffraction unit to 5 μm, the depth to 1 μm, and the phase distribution to linear distribution.

[0094] Step 3: Add a cylindrical lens with a focal length of 50 mm as the refractive optical module 102 and place it at an appropriate position to ensure that the shaped light beam can be focused to a desired position.

[0095] Step 4: Run ray tracing, set the target plane at various positions, observe the generation effect of the line laser, and optimize the position and parameters based on the results.

[0096] The simulation results are as follows Figure 5 As shown, by measuring the distance between the refractive optical module 102 and the target plane 20 (the position where the one-line laser homogenization is optimal and the focusing effect is best), the distance D between the refractive optical module 102 and the target plane 20 is obtained to be 50 mm, that is, the position where the second light beam is best homogenized coincides with the focal position of the refractive optical module 102.

[0097] By implementing the embodiment of the present application, by aligning the best position for shaping the second light beam with the focal position of the refractive optical module 102, the line width of the second light beam can be made as small as possible, and the homogenization effect of the second light beam can be maximized, thereby improving the light beam quality.

[0098] In some embodiments of the present application, the distance between the diffractive optical module 101 and the refractive optical module 102 is greater than or equal to 10 mm.

[0099] For example, as mentioned above Figure 1 and Figure 3 As shown, the distance between the center a of the diffractive optical module 101 and the center b of the refractive optical module 102 is greater than or equal to 10 mm.

[0100] In the embodiment of the present application, by maintaining a sufficient distance (greater than or equal to 10 mm) between the diffraction optical module 101 and the refractive optical module 102, a larger operating space is provided for the assembly and adjustment process, which helps the operator to more easily install, align and adjust the two modules, ensuring that the relative position and angle between them meet the design requirements, thereby improving the assembly efficiency and adjustment accuracy.

[0101] In some embodiments of the present application, when the diffractive optical module 101 is located before the refractive optical module 102, the refractive optical module 102 is also used to output a second light beam to the target plane 20, which can be specifically as follows: Figure 6 As shown. The target plane 20 is a working plane for forming the second light beam. Exemplarily, the target plane 20 may be a working plane for laser cutting or laser scanning. When the refractive optical module 102 is located before the diffractive optical module 101, the diffractive optical module 101 is also used to output the second light beam to the target plane 20, which may be specifically as follows: Figure 7 For example, a schematic diagram of the second light beam on the target plane 20 can be as follows: Figure 8 As shown, the aspect ratio X1:Y1 of the second light beam in the target plane 20 is 10:1, wherein X1 is used to represent the length of the second light beam in a first direction (such as a horizontal direction), and Y1 is used to represent the width (such as a line width) of the second light beam in a second direction (such as a vertical direction).

[0102] By implementing the embodiment of the present application, the second light beam with an aspect ratio of 10:1 can provide higher precision processing, thereby improving the processing accuracy.

[0103] In some embodiments of the present application, the distance between the center a of the refractive optical module 102 and the center b of the target plane 20 along the optical axis is the same as the focal length of the refractive optical module 102, which ensures that a narrower second light beam is obtained on the target plane 20, thereby improving processing accuracy.

[0104] It can be understood that if the diffraction optical module 101 is located before the refractive optical module 102, since the diffraction optical module 101 homogenizes the first light beam (equivalent to collimating it), the light beam incident on the refractive optical module 102 is a collimated light beam, and after the collimated light beam passes through the refractive optical module 102 with a focusing function, a focused light beam is generated, and the waist position of the focused light beam is located on the target plane 20. Therefore, the distance from the center a of the diffraction optical module 101 along the optical axis to the center b of the target plane 20 is exactly equal to the focal length of the refractive optical module 102.

[0105] In the embodiment of the present application, since the light beam reaches the minimum spot size at the focal position, the distance from the center of the refractive optical module 102 to the target plane 20 is set as the focal length, which can ensure that the narrowest second light beam in the second direction is obtained on the target plane 20, thereby improving the energy density of the light beam.

[0106] In some embodiments of the present application, as described above Figure 6 and Figure 7 As shown in FIG. 1 , the target plane 20 is perpendicular to the optical axis of the second light beam. In this case, the target plane 20 is a vertical plane. Figure 6 For example, when the waist diameter of the first light beam (such as a Gaussian light beam) is 2.4 mm, the distance between the center a of the diffractive optical module 101 along the optical axis and the center c of the target plane 20 is 470 mm, the wavelength of the refractive optical module 102 is 266 nm and the focal length is 460 mm, the distance between the center b of the refractive optical module 102 along the optical axis and the center b of the target plane 20 is 460 mm, and the target plane 20 is perpendicular to the optical axis of the second light beam, the schematic diagram of the second light beam on the target plane 20 can be as follows: Fig. 9 As shown, the length X-ray intensity I schematic diagram of the second light beam in the first direction can be as follows: Fig.10 As shown. Fig.10 Within the length range of 1 mm shown, the uniformity of the second light beam is greater than or equal to 90%, and the energy utilization rate of the second light beam is greater than or equal to 80%.

[0107] like Fig.11 and Fig.12 As shown, the angle θ between the target plane 20 and the optical axis of the second light beam is between (0°, 90°), and the target plane 20 is an inclined plane. Fig.11 For example, when the waist diameter of the first light beam (such as a Gaussian light beam) is 2.4 mm, the distance from the center a along the optical axis to the center c is 600 mm, the wavelength of the refractive optical module 102 is 266 nm and the focal length is 460 mm, the distance from the center b along the optical axis to the center c is 460 mm, and the angle θ is 15°, the schematic diagram of the second light beam on the target plane 20 can be as follows: Fig.13As shown, the length X-ray intensity I schematic diagram of the second light beam in the first direction can be as follows: Fig.14 As shown. Fig.14 Within the length range of 1 mm shown, the uniformity of the second light beam is greater than or equal to 90%, and the energy utilization rate of the second light beam is greater than or equal to 80%.

[0108] In the embodiment of the present application, for a vertical plane, the energy of the light beam is concentrated at the center of the light spot, which is suitable for applications requiring high energy density; for an inclined plane, the energy of the light beam can be distributed along a specific direction, which is suitable for applications requiring a specific energy distribution. Regardless of whether it is a vertical plane or an inclined plane, by precisely controlling the relationship between the target plane 20 and the optical axis of the second light beam, the energy distribution of the light beam on the target plane 20 can be optimized, thereby improving the utilization rate of the light beam.

[0109] In some embodiments of the present application, a full width half maximum (FWHM) corresponding to the Gaussian distribution of the second light beam in the second direction is less than 30 μm.

[0110] In some embodiments of the present application, the incident angle of the first light beam is greater than or equal to 70° and less than or equal to 90°, wherein the incident angle is the angle between the incident direction of the first light beam and the normal direction of the target plane 20 .

[0111] By implementing the embodiment of the present application, the size of the incident angle is flexibly adjusted to meet the incident requirements when the light beam conversion device 10 outputs the second light beam.

[0112] In some embodiments of the present application, the above-mentioned light beam transformation device 10 can also be applied to an optical processing device 30, specifically, Fig.15 As shown, the optical processing device 30 is used to transform the first light beam through the light beam transformation device 10 and output the second light beam. The specific process can be seen in the above Figures 1 to 14 The corresponding embodiments are not described in detail here. It is understood that the optical processing device 30 may also include other devices in addition to the beam transformation device 10, including at least one of a light splitting device, a reflection device, and a polarization device. The embodiment of the present application does not limit the specific structure of the optical processing device 30.

[0113] In the embodiment of the present application, since the above-mentioned light beam transformation device 10 is integrated in the optical processing equipment 30, the device can accurately control and adjust the shape, size and direction of the light beam, so that the optical processing equipment 30 can perform high-precision and high-stability optical processing, which can improve the processing accuracy of the optical processing equipment 30.

[0114] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A beam transformation device, used for performing beam transformation on a first beam, characterized in that: It includes a diffraction optical module and a refraction optical module arranged in an optical path, the diffraction optical module and the refraction optical module are used to jointly perform beam transformation on the first light beam and output a second light beam, wherein the light intensity distribution of the second light beam in the first direction is a flat-top distribution, and the light intensity distribution of the second light beam in the second direction is a Gaussian distribution, the first direction and the second direction are both perpendicular to the optical axis of the second light beam, and the first direction is perpendicular to the second direction.

2. The light beam conversion device according to claim 1, characterized in that: The diffraction optical module is located in front of the refractive optical module. The diffraction optical module is used to shape the first light beam in the first direction and output a flat-top beam to the refractive optical module. The refractive optical module is used to focus the flat-top beam in the second direction and output the second light beam.

3. The light beam conversion device according to claim 1, characterized in that: The refractive optical module is located in front of the diffractive optical module. The refractive optical module is used to focus the first light beam in the second direction and output the focused light beam to the diffractive optical module. The diffractive optical module is used to shape the focused light beam in the first direction and output the second light beam.

4. The light beam conversion device according to claim 2 or 3, characterized in that: The diffraction optical module is arranged at the beam waist position of the first light beam or the focused light beam.

5. The light beam conversion device according to claim 2 or 3, characterized in that: The refractive optical module has a curved surface, and the curved surface faces the incident direction of the first light beam or the flat-top light beam.

6. The light beam conversion device according to any one of claims 1 to 3, characterized in that: The diffraction optical module is a multi-step diffraction optical module.

7. The light beam conversion device according to claim 6, characterized in that: The number of steps of the multi-step diffraction optical module is not less than 4.

8. The light beam conversion device according to any one of claims 1 to 7, characterized in that: The diffractive optical module has an incident surface and an exit surface, and at least one of the incident surface and the exit surface is coated with an anti-reflection film.

9. The light beam conversion device according to any one of claims 1 to 8, characterized in that: The refractive optical module includes a plurality of refractive optical elements, each of which has a curved surface, and the generatrix directions of the plurality of curved surfaces are the same.

10. The light beam conversion device according to any one of claims 1 to 9, characterized in that: The position where the second light beam is best homogenized coincides with the focal position of the refractive optical module.

11. The light beam conversion device according to any one of claims 1 to 10, characterized in that: The distance between the diffraction optical module and the refraction optical module is greater than or equal to 10 mm.

12. The light beam conversion device according to any one of claims 1 to 11, characterized in that: The aspect ratio of the second light beam in the target plane is 10:

1.

13. The light beam conversion device according to claim 12, characterized in that: The distance between the center of the refractive optical module and the center of the target plane along the optical axis is the same as the focal length of the refractive optical module.

14. The light beam conversion device according to claim 12 or 13, characterized in that: The target plane is perpendicular to the optical axis of the second light beam, or the angle between the target plane and the optical axis of the second light beam is between (0°, 90°).

15. An optical processing device, characterized in that: include: A light beam conversion device as claimed in any one of claims 1 to 14.

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