Optical system and optical apparatus

Abstract

The invention provides an optical system and optical equipment. The optical system comprises a light source, a dodging piece and a beam splitter, wherein the light source is used for emitting a first light beam; the light uniformizing part comprises a plurality of light uniformizing units arranged along a straight line, and the light uniformizing units are used for receiving the first light beam and performing light field intensity uniformizing treatment on the first light beam to obtain a second light beam and emitting the second light beam; the beam splitter is used for receiving the second light beam and splitting the second light beam into a plurality of sub light beams. According to the invention, the far-field distribution difference of the plurality of sub-beams is small.

Description

Technical Field

[0001] The present application relates to the field of optical manufacturing and detection technology, and in particular to an optical system and optical equipment. Background Art

[0002] Optical systems play an important role in the modern information society. For example, materials required for information generation and transmission are usually processed and tested using optical equipment including optical systems.

[0003] In the related art, an optical device includes an optical system and multiple optical components. The optical system includes a light source and a beam splitter. The light source can emit a light beam to the beam splitter. After receiving the light beam, the beam splitter splits the light beam into multiple sub-beams and emits the multiple sub-beams to multiple optical components respectively.

[0004] Since the intensity distribution of the light beam emitted by the light source is Gaussian or quasi-Gaussian, that is, the intensity difference between the central part and the edge part of the cross section of the light beam is large. Among the multiple sub-beams obtained by the beam splitter, some sub-beams have high intensity and some have low intensity, which will lead to large differences in the far-field distribution of each sub-beam. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides an optical system and an optical device, which can reduce the difference in far-field distribution of multiple sub-beams.

[0006] The present application provides an optical system, including a light source, a light homogenizer and a beam splitter. The light source may be a laser light source. The light source is used to emit a first light beam.

[0007] The light homogenizer includes a plurality of light homogenizer units arranged along a straight line, so the light homogenizer is a one-dimensional light homogenizer. The one-dimensional light homogenizer has the characteristic of high manufacturing precision. However, short-wavelength light beams require high processing precision of optical devices such as light homogenizers, so the optical system of the present application can be applied to short-wavelength light beams.

[0008] Multiple light homogenizing units are used to receive the first light beam and perform light field intensity homogenization processing on the first light beam. Since the light homogenizer is a one-dimensional light homogenizer, after receiving the first light beam, the multiple light homogenizing units can perform light field intensity homogenization processing on the first light beam along one direction. For example, multiple light homogenizing units can perform light field intensity homogenization processing on the first light beam along a third direction. Exemplarily, each light homogenizing unit can receive a portion of the first light beam, and perform light field intensity homogenization processing on the portion of the first light beam along the third direction to obtain a portion of the second light beam, and emit the portion of the second light beam to the beam splitter. The beam splitter is used to receive the second light beam and split the second light beam into multiple sub-beams.

[0009] It can be understood that the propagation direction of the first light beam can be a first direction, and the second direction and the third direction can both be directions perpendicular to the first direction.

[0010] Since the intensity distribution of the first light beam emitted by the light source is usually Gaussian distribution or quasi-Gaussian distribution, that is, the intensity of the central part of the cross section of the first light beam is higher, the intensity of the edge part of the cross section is lower, and the intensity difference between the central part of the cross section and the edge part of the cross section is large. Exemplarily, the intensity distribution of the cross section of the first light beam along the second direction is Gaussian distribution or quasi-Gaussian distribution, and the intensity distribution of the cross section of the first light beam along the third direction is also Gaussian distribution or quasi-Gaussian distribution. Multiple light homogenization units can perform light field intensity homogenization processing on the first light beam emitted by the light source along the third direction, and the first light beam that originally has Gaussian distribution or quasi-Gaussian distribution along the second direction and Gaussian distribution or quasi-Gaussian distribution along the third direction is processed by light field intensity homogenization to be a second light beam whose intensity along the second direction is Gaussian distribution or quasi-Gaussian distribution, and whose intensity along the third direction is nearly flat-top distribution, that is, the cross section of the second light beam obtained after light field intensity homogenization processing has a small difference between the intensity of the central part and the intensity of the edge part in the third direction. The beam splitter can split the received second light beam into multiple sub-beams, so the cross-section of the multiple sub-beams split from the second light beam has a smaller difference between the intensity of the center portion and the intensity of the edge portion in the third direction. The far-field distribution of the sub-beams can be characterized by the intensity of the sub-beams and the intensity distribution, so the intensity distribution of each sub-beam is more uniform, that is, the difference in the far-field distribution of each sub-beam is smaller.

[0011] In addition, since the light source is usually not a completely constant light source, there is often a certain jitter when emitting the first light beam, that is, the first light beam has a certain jitter. When the light homogenizer includes multiple light homogenizer units, each light homogenizer unit will perform light field intensity homogenization processing on a portion of the first light beam, and each light homogenizer unit can improve the jitter of the received portion of the first light beam, thereby improving the situation where the jitter of the sub-beams split by the final beam splitter is too large due to the jitter of the light source.

[0012] In some possible implementations, the first light homogenizing unit is a beam expansion light homogenizing unit, and the first light homogenizing unit is a light homogenizing unit among multiple light homogenizing units. The beam expansion light homogenizing unit is specifically used to receive part of the first light beam and perform light field intensity homogenization and beam expansion on part of the first light beam to obtain part of the second light beam. When each light homogenizing unit is a beam expansion light homogenizing unit, multiple beam expansion light homogenizing units can perform light field intensity homogenization and beam expansion on the first light beam and obtain the second light beam, thereby making the energy of the second light beam more dispersed, thereby making the heat more dispersed, and thus facilitating the heat dissipation of the optical system. In this way, the situation in which the light homogenizing component or beam splitter in the optical system is damaged due to untimely heat dissipation of the optical system can be reduced, thereby increasing the service life of the light homogenizing component and the beam splitter. In addition, after the beam expansion light homogenizing unit performs beam expansion on the first light beam and obtains the second light beam, the width of the second light beam can be increased, thereby making the size of the beam splitter that receives the second light beam and splits the second light beam moderate, which is convenient for the processing of the beam splitter.

[0013] In some possible implementations, the light homogenizer unit has a first mirror surface for receiving the first light beam and emitting the second light beam, and the first mirror surface is a cylinder, a spherical surface, or a free-form surface. Since a cylinder can usually be applied to a mirror surface with a large difference between length and width, the light homogenizer is a one-dimensional light homogenizer, that is, when a plurality of light homogenizer units are arranged in a straight line, the first mirror surface can be a cylinder.

[0014] Regarding the structure of the light homogenizer, in one possible embodiment, the light homogenizer can be an integrally molded structure, that is, a plurality of first mirror surfaces arranged in a straight line are processed on a raw material. In another possible embodiment, each light homogenizer unit can be processed separately, and each light homogenizer unit can be spliced ​​into a light homogenizer. In another possible embodiment, a plurality of light homogenizer unit assemblies can be processed, and the light homogenizer unit assembly includes at least two light homogenizer units, and then each light homogenizer unit assembly is spliced ​​into a light homogenizer. In another possible embodiment, at least one light homogenizer unit can be processed, and at least one light homogenizer unit assembly can be processed, and at least one light homogenizer unit and at least one light homogenizer unit assembly can be spliced ​​into a light homogenizer.

[0015] In some possible implementations, the radius of curvature R1 of the first mirror satisfies: 5mm≤R1≤10000mm. If the radius of curvature R1 of the first mirror is less than 5mm, the divergence angle of the second light beam reflected from the first mirror will be larger. To ensure that the beam splitter can receive the second light beam, the size of the beam splitter needs to be set to a larger size, which will increase the cost of the beam splitter. If the radius of curvature R1 of the first mirror is greater than 10000mm, the size of the homogenizing unit is too large, which will cause the size of the optical system to be too large. Therefore, when the radius of curvature R1 of the first mirror satisfies 5mm≤R1≤10000mm, the size of the optical system will not be too large.

[0016] In some possible implementations, the number m1 of the light homogenizing units satisfies: 5≤m1≤1000. Since each light homogenizing unit can improve the jitter of the portion of the first light beam in the process of receiving the portion of the first light beam emitted by the light source and emitting the portion of the second light beam, and the more the number m1 of the light homogenizing units is, the better the improvement effect on the jitter of the first light beam is. Therefore, if the number m1 of the light homogenizing units is less than 5, the improvement effect of the jitter of the first light beam by each light homogenizing unit is poor, that is, the second light beam still has a large jitter. If the number m1 of the light homogenizing units is greater than 1000, the size of the light homogenizing member is larger, thereby resulting in a larger size of the optical system. Therefore, when the number m1 of the light homogenizing units satisfies: 5≤m1≤1000, it is possible to maintain a good improvement effect on the jitter of the first light beam while avoiding increasing the size of the optical system.

[0017] In some possible implementations, the length L1 of the light homogenizing unit satisfies: 5mm≤L2≤100mm; the width L2 of the light homogenizing unit satisfies: 1mm≤L1≤10mm, and the length direction of the light homogenizing unit is perpendicular to the first direction, and the first direction is the arrangement direction of the light source and the light homogenizing element. If the length L1 of the light homogenizing unit is less than 5mm, and the width L2 of the light homogenizing unit is less than 1mm, the size of the light homogenizing unit is too small to be easily processed, and the processing accuracy is low; if the length L1 of the light homogenizing unit is greater than 100mm, and the width L2 of the light homogenizing unit is greater than 10mm, the size of the light homogenizing unit is too large, thereby causing the size of the optical system to be too large. Therefore, when the length L1 of the light homogenizing unit satisfies: 5mm≤L2≤100mm, and the width L2 of the light homogenizing unit satisfies: 1mm≤L1≤10mm, the size of the light homogenizing unit is moderate, which can not only ensure the processing accuracy of the light homogenizing unit, but also avoid increasing the size of the optical system.

[0018] Regarding the positional relationship between the normals of the first mirror surface of each light-diffusing unit, in a possible implementation, the normals of the first mirror surface of each light-diffusing unit are parallel, or in other words, the normals of the first mirror surfaces of every two adjacent light-diffusing units are parallel. In this way, it is convenient to uniformly manufacture each light-diffusing unit, thereby making the manufacture of the light-diffusing element more convenient and simple.

[0019] In this case, the optical system may further include a correction mirror, which is located between the light homogenizer and the beam splitter, and the correction mirror may be a reflector. The correction mirror may be used to receive and adjust the beam pointing of the second light beam, and emit the second light beam after the beam pointing is adjusted to the beam splitter. Or, the correction mirror may be used to receive and adjust the divergence angle of the second light beam, and emit the second light beam after the divergence angle is adjusted to the beam splitter. Or, the correction mirror may be used to receive and adjust the beam pointing and divergence angle of the second light beam, and emit the second light beam with the beam pointing and divergence angle to the beam splitter. In this way, it is convenient for the beam splitter to receive all the second light beams. Moreover, since each optical component has certain requirements for the incident angle of the sub-beam incident to itself, when the correction mirror receives the second light beam, it can adjust the beam pointing and divergence angle of the second light beam according to the incident angle requirement incident to the optical component.

[0020] Moreover, the correction mirror has a third mirror surface for receiving the second light beam, and the third mirror surface is a plane, a cylinder, a spherical surface or a free-form surface. When only the beam direction of the second light beam needs to be adjusted, the third mirror surface can be selected as a plane, so that the processing difficulty of the correction mirror is relatively low. When the beam direction and divergence angle of the second light beam need to be adjusted, the third mirror surface can be processed to be a cylinder, a spherical surface or a free-form surface. Moreover, the beam direction of the second light beam can be adjusted by adjusting the incident angle of the second light beam incident on the correction mirror, and the divergence angle of the second light beam can be adjusted by adjusting the curvature radius of the third mirror surface.

[0021] In another possible implementation, the normals of the first mirrors of each light homogenizing unit have an angle therebetween. For example, the normals of the first mirrors of two adjacent light homogenizing units have a first angle a1 therebetween. In this way, the light homogenizing unit can not only perform light field intensity homogenization processing on the received part of the first light beam, but also adjust the beam pointing and / or divergence angle of the part of the first light beam. Therefore, in this case, a correction mirror may not be required in the optical system. This can reduce the number of components of the optical system, thereby reducing the cost of the optical system.

[0022] Moreover, the first angle a1 satisfies: a1≤2°. If the first angle a1 is greater than 2°, the grazing angle of incidence of the first light beam incident on some of the light homogenizing units will be too large, thereby emitting the second light beam to an area outside the beam splitter, that is, the second light beam cannot be emitted to the beam splitter. Therefore, when the first angle a1 satisfies: a1≤2°, each light homogenizing unit can emit the second light beam to the beam splitter after receiving the first light beam.

[0023] In some possible implementations, the light homogenizer is a reflector, and the grazing reflection angle r of the second light beam satisfies: 0.1°≤r≤20°; the grazing reflection angle r is the complementary angle of the reflection angle of the second light beam. If the grazing reflection angle r of the second light beam is less than 0.1°, the reflector cannot receive the first light beam; if the grazing reflection angle r is greater than 20°, the reflectivity of the reflector is too low, resulting in loss of light energy, and thus resulting in low light energy utilization. Therefore, when the grazing reflection angle r of the second light beam satisfies: 0.1°≤r≤20°, the reflector can both receive the first light beam and keep the light energy utilization rate unchanged.

[0024] In some possible implementations, a plurality of flow channels are provided inside the light diffuser. In actual use of the optical system, the light diffuser generates heat, and the plurality of flow channels facilitate heat dissipation, thereby reducing the possibility of damage to the light diffuser due to untimely heat dissipation, thereby extending the service life of the light diffuser.

[0025] In some possible implementations, the beam splitter includes a plurality of beam splitting units, and the plurality of beam splitting units are arranged in a straight line. Each beam splitting unit is in the shape of a long strip. The orthographic projection shape of the mirror surface of the beam splitting unit is a rectangle. Each beam splitting unit is arranged in sequence along its width direction. Since the plurality of beam splitting units are arranged in a straight line, the optical components for receiving the sub-beams emitted by each beam splitting unit can also be arranged in a straight line.

[0026] In another possible implementation, the plurality of beam splitting units are arranged in a rectangular array. The orthographic projection shape of the mirror surface of each beam splitting unit may be a square, a circle, or a rectangle with a small difference between the long side and the short side.

[0027] Moreover, the beam splitting unit has a second mirror surface for receiving the second light beam, and the second mirror surface of any beam splitting unit is a cylinder, a spherical surface, a plane or a free-form surface. In one possible embodiment, the surface shape of the second mirror surface of each beam splitting unit is the same. For example, the second mirror surface of each beam splitting unit is a plane. Thereby, the second mirror surface of each beam splitting unit can be easily processed, and the processing cost of each beam splitting unit can be reduced. Or, the second mirror surface of each beam splitting unit is a cylinder. Or, the second mirror surface of each beam splitting unit is a spherical surface. Or, the second mirror surface of each beam splitting unit is a free-form surface. In another possible embodiment, the surface shapes of the second mirror surfaces of some beam splitting units are the same, and the surface shapes of the second mirror surfaces of some beam splitting units are different. For example, the second mirror surfaces of some beam splitting units are cylinders, and the mirror surfaces of some beam splitting units are planes.

[0028] Regarding the arrangement of the multiple beam splitting units, in a possible implementation manner, the multiple beam splitting units are arranged along a second direction, and the second direction is perpendicular to a propagation direction of the second light beam.

[0029] When the second mirror surface of each beam splitting unit is a plane, a second angle a2 is formed between two adjacent second mirror surfaces. Thus, when the second light beam is irradiated to a plurality of beam splitting units, two adjacent second mirror surfaces with the second angle a2 can reflect part of the second light beam irradiated to themselves to optical components at different positions, thereby providing a sub-beam for each optical component.

[0030] When the second mirror surface of each beam splitting unit is a cylindrical surface or a spherical surface, the normal lines of the second mirror surfaces of two adjacent beam splitting units have a second angle a2. In this way, when the second light beam is irradiated to multiple beam splitting units, the two adjacent second mirror surfaces whose normal lines have the second angle a2 can reflect part of the second light beam irradiated to themselves to optical components at different positions, thereby providing a sub-beam for each optical component.

[0031] Moreover, the second angle a2 satisfies: 0.1°≤a2≤5°. When the second angle a2 is less than 0.1°, the second angle a2 of the second mirror of two adjacent beam splitting units is small, or the second angle a2 between the normals of the second mirror of two adjacent beam splitting units is small, resulting in a small distance between the sub-beams emitted by the two adjacent beam splitting units, resulting in a small distance between the optical components receiving the two sub-beams. Since each optical component also occupies a certain space, in order to meet a sufficient distance between the optical components, the optical components need to be placed at a position far away from the beam splitter, which will cause the size of the optical system to be too large. When the second angle a2 is greater than 5°, since the direction of the second light beam incident on the beam splitter is fixed, when the second angle a2 is too large, the grazing angle of the second light beam incident on part of the beam splitting unit will be large, and the grazing reflection angle when the beam splitting unit reflects the second light beam will also be large, resulting in a low light energy utilization rate of the light beam. Therefore, when the second angle a2 satisfies: 0.1°≤a2≤5°, the second angle a2 is moderate, which can avoid the optical system from being too large and the light energy utilization rate from being low.

[0032] The plurality of beam splitting units are arranged in parallel along the first direction, and there is a spacing between two adjacent beam splitting units in the first direction. The plurality of beam splitting units are staggered along the Z direction. That is, the position of each beam splitting unit along the Z direction is different. In this way, the plurality of beam splitting units can split the second light beam and obtain a plurality of sub-beams.

[0033] In some possible implementations, the grazing incidence angle σ of the second light beam incident on the beam splitter satisfies: 0.1°≤σ≤30°. When the grazing incidence angle σ is less than 0.1°, it indicates that the grazing incidence angle σ is too small, and the reflection function of the beam splitter cannot be achieved. When the grazing incidence angle σ is greater than 30°, the grazing reflection angle when the beam splitting unit reflects the second light beam is also large, resulting in a low light energy utilization rate of the light beam. Therefore, when the grazing incidence angle σ satisfies: 0.1°≤σ≤30°, the grazing incidence angle σ is moderate, thereby avoiding the situation of low light energy utilization rate.

[0034] In some possible implementations, the plurality of beam splitting units include a first beam splitting unit and a second beam splitting unit, and the relationship between the radius of curvature R2 of the first beam splitting unit and the grazing incidence angle σ1 of the second light beam incident to the first beam splitting unit, and the radius of curvature R3 of the second beam splitting unit and the grazing incidence angle σ2 of the second light beam incident to the second beam splitting unit satisfies: R2:R3=(1 / σ1):(1 / σ2). When the grazing incidence angle of the second light beam incident to the first beam splitting unit is small, and the grazing incidence angle of the second light beam incident to the second beam splitting unit is large, if the radius of curvature of each beam splitting unit is the same, the lateral area of ​​the sub-beam emitted from the first beam splitting unit is large, and the lateral area of ​​the sub-beam emitted from the second beam splitting unit is small, which will result in different lateral areas of the sub-beams. By setting the relationship between the radius of curvature R2 and the grazing incidence angle σ1 of the first beam splitting unit and the radius of curvature R3 and the grazing incidence angle σ2 of the second beam splitting unit to: R2:R3=(1 / σ1):(1 / σ2), and adjusting the radius of curvature of each beam splitting unit according to the size relationship between the grazing incidence angles of the second light beam incident on the beam splitting unit, the lateral area of ​​each sub-beam can be made as similar as possible, thereby further making the far-field distribution of each sub-beam approximate.

[0035] In some possible implementations, the length L3 of the beam splitter unit satisfies: 10mm≤L3≤1000mm, the width L4 of the beam splitter unit satisfies: 1mm≤L4≤30mm, and the width direction of the beam splitter unit is perpendicular to the first direction, and the first direction is the arrangement direction of the light source and the light homogenizer. If the length L3 of the beam splitter unit is less than 10mm, and the width L4 of the beam splitter unit is less than 1mm, the size of the beam splitter unit is too small to be easily processed, and the processing accuracy is low; if the length L3 of the beam splitter unit is greater than 1000mm, and the width L4 of the beam splitter unit is greater than 30mm, the size of the beam splitter unit is too large, thereby causing the size of the optical system to be too large. Therefore, when the length L3 of the beam splitter unit satisfies: 10mm≤L3≤1000mm, and the width L4 of the beam splitter unit satisfies: 1mm≤L4≤30mm, the size of the beam splitter unit is moderate, which can not only ensure the processing accuracy of the beam splitter unit, but also avoid increasing the size of the optical system.

[0036] In some possible implementations, the number m2 of beam splitting units satisfies: 2≤m2≤20. The number m2 of beam splitting units may be the same as the number of optical components, that is, each optical component receives a sub-beam emitted by each beam splitting unit in a one-to-one correspondence. When the number m2 of beam splitting units is less than 2, the number of beam splitting units is 1, and the beam splitter cannot achieve the effect of beam splitting. When the number m2 of beam splitting units is greater than 20, the number of beam splitting units is too large, and the corresponding number of optical components is also too large, resulting in an oversized optical system. Therefore, when the number m2 of beam splitting units satisfies: 2≤m2≤20, the number m2 of beam splitting units is moderate, which can achieve the effect of beam splitting and avoid increasing the size of the optical system.

[0037] The present application also provides an optical device, comprising a plurality of optical components and an optical system according to any one of the above embodiments of the claims, wherein the optical system is used to send sub-beams to each optical component respectively. The optical device can achieve all the effects of the above optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0039] Figure 1 This is a schematic diagram of the structure of an optical device in an embodiment of the present application;

[0040] Figure 2 This is a schematic diagram of the specific structure of the optical device in the first embodiment of the present application;

[0041] Figure 3 for Figure 2 A top view of

[0042] Figure 4a is a comparison diagram of the intensity distribution of the second light beam before and after the light field intensity uniformization process;

[0043] Figure 4b The intensity distribution comparison diagram of the second light beam before and after the light field intensity homogenization and beam expansion processing is performed;

[0044] Figure 5 for Figure 2 A diagram showing the position relationship between a light homogenizing element and a correction element in the optical device shown;

[0045] Figure 6a A structural schematic diagram of a light homogenizing element;

[0046] Figure 6bis another structural schematic diagram of a light homogenizing element;

[0047] Figure 7 for Figure 2 A schematic diagram of the optical device in which a beam splitter splits a second light beam into a plurality of sub-beams;

[0048] Figure 8 is a schematic structural diagram of an optical device in a second embodiment;

[0049] Fig. 9 is a schematic structural diagram of an optical device in a third embodiment;

[0050] Fig.10 for Fig. 9 A top view of

[0051] Fig.11 Schematic diagram of the structure of the optical device in the fourth embodiment.

[0052] Icons: 1-optical device; 2-optical system; 21-light source; 22-light homogenizer; 221-light homogenizer unit; 222-flow channel; 223-first mirror; 23-beam splitter; 231-beam splitter unit; 2311-second mirror; 24-first light beam; 25-second light beam; 26-sub-beam; 27-correction mirror; 271-third mirror; 3-optical component. DETAILED DESCRIPTION

[0053] 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.

[0054] The term "and / or" herein is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone, wherein A and B may be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one (item)" means one or more, and "plurality" means two or more. "At least one of the following (items)" or similar expressions refers to any combination of these items, including any combination of single (items) or plural (items). For example, at least one (item) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or multiple.

[0055] 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.

[0056] "Connected", "connected" and similar words are used to express the intercommunication or interaction between different components, which may include direct connection or indirect connection through other components. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, inclusion of a series of steps or units. Methods, systems, products or devices are not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. "Up", "down", "left", "right" and the like are only used relative to the orientation of the components in the drawings. These directional terms are relative concepts. They are used for description and clarification relative to the description, which may change accordingly according to the change of the orientation of the components in the drawings.

[0057] 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.

[0058] 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.

[0059] To facilitate understanding of the optical system provided in the embodiments of the present application, the following terms are explained:

[0060] Grazing incidence: refers to the propagation of light from one medium to another, with an angle of incidence close to 90 degrees, where the angle of incidence is the angle between the incident light and the mirror normal.

[0061] Grazing incidence angle: refers to the complementary angle of the incident angle, that is, the grazing incidence angle is the difference between 90° and the incident angle.

[0062] Beam pointing: The direction in which a beam of light travels.

[0063] Divergence angle: A measure of how quickly a beam of light diverges from the beam waist.

[0064] Far-field distribution: can usually be characterized by the intensity and intensity distribution of the beam.

[0065] Optical systems play an important role in the modern information society. For example, materials required for information generation and transmission are usually processed and tested using optical equipment including optical systems.

[0066] Optical equipment can generally be divided into imaging optical equipment and non-imaging optical equipment. Among them, imaging optical equipment can clearly image objects onto the required medium, which greatly improves the cognition and productivity of human society. Imaging optical equipment can be, for example, cameras, microscopes, projectors, material processing and testing equipment, and medical equipment. Imaging optical equipment may include an optical system and an optical component, and the optical system may be an imaging optical system. The optical component may be a component that receives a light beam emitted by the imaging optical system and is used to obtain an image or produce. Exemplarily, when the imaging optical equipment is a camera, the optical component may be a lens; when the imaging optical equipment is a material processing and testing equipment, the optical component may be a test bench; when the imaging optical equipment is a medical device, the optical component may be a treatment bench. Non-imaging optical equipment may be, for example, a car lighting, a display, and the like. Non-imaging optical equipment may include an optical system and a controller.

[0067] With the continuous evolution of optical technology, the optical resolution of optical systems has been continuously improved, and the imaging wavelength has been continuously reduced from the visible light band to the short wavelength band. Therefore, optical systems can be divided into visible light wave optical systems and short wavelength optical systems.

[0068] The short-wavelength optical system is an optical system that uses short-wavelength soft X-rays with a wavelength of 1nm to 30nm as the imaging light source. Since the optical materials in the short-wavelength optical system have strong absorption of the short-wavelength band, the short-wavelength optical system needs to work in a vacuum environment and use reflectors to reduce absorption losses and improve light energy utilization.

[0069] The short-wavelength light sources used in short-wavelength optical systems include radiation light sources, such as synchrotron radiation, free electron lasers, etc. Among them, radiation light sources will become the next generation of short-wavelength light sources due to their extremely high brightness, pollution-free, and adjustable wavelength. Since radiation light sources have the characteristics of high brightness, for example, the brightness can reach 10kW, when used, the radiation light source requires an optical system to split a beam of light into multiple sub-beams with moderate energy, such as splitting into sub-beams with an energy of 500W to match multiple optical components. In this process, the energy of different sub-beams is required to be similar and the far-field distribution is similar. In addition, for economic reasons, it is hoped that the optical system's light energy utilization rate will be as high as possible.

[0070] In the first related technology, the optical system includes a light source and a beam splitter. The light source can emit a light beam to the beam splitter. After receiving the light beam, the beam splitter splits the light beam into multiple sub-beams.

[0071] Since the intensity distribution of the cross section of the light beam emitted by the light source is Gaussian distribution or quasi-Gaussian distribution, that is, the intensity of the central part of the cross section of the first light beam is higher, the intensity of the edge part of the cross section is lower, and the intensity difference between the central part and the edge part is large. Among the multiple sub-beams obtained by beam splitting by the beam splitter, the intensity of some sub-beams is higher and the intensity of some sub-beams is lower, which will lead to a large difference in the far-field distribution of each sub-beam.

[0072] Moreover, multiple sub-beams need to be emitted to multiple optical components respectively, so that the optical components can detect or process based on the received sub-beams. In order to reduce the difference in far-field distribution of the sub-beams reaching each optical component, it is necessary to add an optical element between the beam splitter and the optical component of the optical system to improve the difference in far-field distribution of the sub-beams, which will increase the cost of the optical equipment.

[0073] In a second related technology, an optical system includes a light source and a grating. The light source can emit a light beam to the grating, and the grating can split the received light beam into sub-beams of multiple diffraction orders.

[0074] However, since the light beam can be a short-wavelength light beam, the grating is also a short-wavelength grating. However, the processing accuracy of the short-wavelength grating is low, and it is difficult to process a grating that meets the spectroscopic accuracy. Moreover, the use of the grating will generate more stray light, resulting in a low light energy utilization rate.

[0075] In the third related art, the optical system includes a light source and a rotatable gear device. The gear device is provided with reflectors and transmission mirrors at intervals along its circumferential direction. The light source can emit a light beam to the gear device, the light beam irradiated on the reflector is reflected to the optical component, and the light beam irradiated on the transmission mirror is transmitted and irradiated to different optical components.

[0076] In use, the gear device rotates around its own axis. When the light beam emitted by the light source is a pulsed light beam, for the optical component that receives the reflected light beam, when the transmission mirror rotates to correspond to the optical component, the optical component cannot receive the light beam, so the repetition frequency of the light beam received by the optical component is reduced, which will cause the speckle of the light field to increase.

[0077] Based on this, an embodiment of the present application provides an optical system, which can be applied to an optical device. When the optical device is an imaging optical device, such as Figure 1 As shown, the optical device may include a plurality of optical components in addition to the optical system.

[0078] For the convenience of description, three directions can be defined, namely the first direction (X direction), the second direction (Y direction) and the third direction (Z direction). Among them, the X direction represents the length direction of the optical system, the Y direction represents the width direction of the optical system, and the Z direction represents the height direction of the optical system. The X direction, the Y direction and the Z direction are perpendicular to each other.

[0079] like Figure 2 As shown, the optical system 2 may include a light source 21, a light homogenizer 22 and a beam splitter 23 arranged in sequence. The light source 21 is used to emit a first light beam 24.

[0080] The light homogenizer 22 includes a plurality of light homogenizer units 221 arranged in a straight line, so that the light homogenizer 22 is a one-dimensional light homogenizer. A one-dimensional light homogenizer has the characteristic of high manufacturing precision. However, short-wavelength light beams require high processing precision of optical devices such as the light homogenizer 22, so the optical system 2 of the embodiment of the present application can be applied to short-wavelength light beams.

[0081] The multiple light homogenizing units 221 are used to receive the first light beam 24 and perform light field intensity homogenization processing on the first light beam 24. Since the light homogenizing element 22 is a one-dimensional light homogenizing element, the multiple light homogenizing units 221 can perform light field intensity homogenization processing on the first light beam 24 along one direction after receiving the first light beam 24. For example, the multiple light homogenizing units 221 can perform light field intensity homogenization processing on the first light beam 24 along the Z direction. Exemplarily, each light homogenizing unit 221 can receive a portion of the first light beam 24, and perform light field intensity homogenization processing on the portion of the first light beam 24 along the Z direction to obtain a portion of the second light beam 25, and emit the portion of the second light beam 25 to the beam splitter 23. The beam splitter 23 is used to receive the second light beam 25 and split the second light beam 25 into multiple sub-beams 26. As shown in FIG. Figure 3 As shown, the beam splitter 23 can send multiple sub-beams 26 to each optical component 3 respectively.

[0082] Since the intensity distribution of the first light beam emitted by the light source is generally a Gaussian distribution or a quasi-Gaussian distribution, that is, the intensity of the central portion of the cross section of the first light beam is higher, the intensity of the edge portion of the cross section is lower, and the intensity difference between the central portion of the cross section and the edge portion of the cross section is relatively large. For example, Figure 4a As shown, the intensity distribution of the cross section of the first light beam 24 along the Y direction is Gaussian distribution or quasi-Gaussian distribution, and the intensity distribution of the cross section of the first light beam 24 along the Z direction is also Gaussian distribution or quasi-Gaussian distribution. The multiple light homogenization units 221 can perform light field intensity homogenization processing on the first light beam 24 emitted by the light source 21 along the Z direction, and can process the light field intensity of the first light beam 24 that originally has a Gaussian distribution or quasi-Gaussian distribution along the Y direction and a Gaussian distribution or quasi-Gaussian distribution along the X direction into a second light beam 25 with a Gaussian distribution or quasi-Gaussian distribution along the Y direction and a nearly flat-top distribution of intensity along the Z direction. That is, as Figure 4aAs shown, in the cross section of the second light beam 25 obtained after the light field intensity is uniformly processed, the difference between the intensity of the central part and the intensity of the edge part in the Z direction is small. Figure 2 As shown, the beam splitter 23 can split the received second light beam 25 into multiple sub-beams 26. Therefore, in the cross-section of the multiple sub-beams 26 split from the second light beam 25, the difference between the intensity of the central part and the intensity of the edge part is also small in the Z direction. The far-field distribution of the sub-beams 26 can be characterized by the intensity of the sub-beams 26 and the distribution of the intensity. Therefore, the intensity distribution of each sub-beam 26 is more uniform, that is, the difference in the far-field distribution of each sub-beam 26 is small.

[0083] It can be understood that the cross section of the first light beam 24 may refer to a plane intercepting the first light beam 24 along a surface perpendicular to the propagation direction of the first light beam 24 .

[0084] When the optical system 2 is applied to the optical device 1, and the optical device 1 further includes the optical component 3, there is no need to provide an optical element for improving the far-field distribution difference between the optical system 2 and the optical component 3, thereby reducing the cost of the optical device 1.

[0085] In addition, since the light source 21 is usually not a completely constant light source 21, there is often a certain jitter when emitting the first light beam 24, that is, there is a certain jitter in the first light beam 24. When the light homogenizer 22 includes a plurality of light homogenizer units 221, each light homogenizer unit 221 will perform light field intensity homogenization processing on a portion of the first light beam 24, and each light homogenizer unit 221 can improve the jitter of the received portion of the first light beam 24, thereby improving the situation where the jitter of the sub-beam 26 split by the final beam splitter is too large due to the jitter of the light source 21.

[0086] In addition, in the embodiment of the present application, there is no need to use a grating, so there is no situation where the grating is a short-wavelength grating and the processing accuracy of the short-wavelength grating is low, making it difficult to process a grating that meets the spectroscopic accuracy. Moreover, there is no situation where more stray light is generated due to the use of the grating, resulting in a low light energy utilization rate.

[0087] In addition, in the embodiment of the present application, after receiving the second light beam 25, the beam splitter 23 can split the second light beam 25 and obtain multiple sub-beams 26. Therefore, the repetition frequency of each sub-beam 26 is the same as the repetition frequency of the second light beam 25, and the repetition frequency of each sub-beam 26 is also the same as the repetition frequency of the first light beam 24. Therefore, the increase in speckle of the light field due to the reduction in the repetition frequency of the sub-beams 26 will not occur.

[0088] Next, each component of the optical system 2 according to the embodiment of the present application is described in detail.

[0089] The light source 21 may be a laser light source, specifically a short-wavelength light source. The light source 21 may emit a first light beam 24, the first light beam 24 may propagate along the X direction, and the divergence angle may be in the range of 0 to 2°. The wavelength λ of the first light beam 24 may be in the range of 3 nm to 120 nm. Synchrotron radiation, free electron laser, etc. may be used.

[0090] The light source 21 may be a continuous wave light source or a pulse light source. When the light source 21 is a pulse light source, the pulse width δ may be in the order of femtoseconds, picoseconds, nanoseconds, microseconds, or milliseconds, etc. The pulse repetition frequency of the pulse light source may range from a few Hz to several hundred GHz.

[0091] In this embodiment, if Figure 2 As shown, the light homogenizer 22 can be a reflector. After the first light beam 24 is irradiated to the reflector, the light field intensity is homogenized, the beam is expanded, and reflected as a second light beam 25. The grazing reflection angle r of the second light beam 25 satisfies: 0.1°≤r≤20°; the grazing reflection angle r is the complementary angle of the reflection angle of the second light beam 25. If the grazing reflection angle r of the second light beam 25 is less than 0.1°, the reflector cannot receive the first light beam 24; if the grazing reflection angle r is greater than 20°, the reflectivity of the reflector is too low, resulting in a loss of light energy, and then resulting in a low light energy utilization rate. Therefore, when the grazing reflection angle r of the second light beam 25 satisfies: 0.1°≤r≤20°, the reflector can both receive the first light beam 24 and keep the light energy utilization rate as unchanged as possible.

[0092] In this embodiment, the first light homogenizing unit among the multiple light homogenizing units 221 may be a beam expanding light homogenizing unit. The number of the first light homogenizing units may be one or more. When the number of the first light homogenizing units is multiple, the number of the first light homogenizing units may be the same as the number of the light homogenizing units 221, that is, each light homogenizing unit 221 is a beam expanding light homogenizing unit. After receiving a portion of the first light beam 24, the beam expanding light homogenizing unit 221 may not only perform light field intensity homogenization processing on the portion of the first light beam 24, but also perform beam expansion processing on the portion of the first light beam 24 to obtain a portion of the second light beam 25. Therefore, the multiple beam expanding light homogenizing units 221 may perform light field intensity homogenization processing and beam expansion processing on the first light beam 24 to obtain the second light beam 25. As Figure 4bAs shown, before the first light beam 24 is subjected to light field intensity homogenization and beam expansion, the aspect ratio of the first light beam 24 is usually 1, and the intensity distribution along the Y direction and the Z direction is Gaussian distribution or quasi-Gaussian distribution. After the first light beam 24 is subjected to light field intensity homogenization and beam expansion by multiple beam expansion and homogenization units, the aspect ratio of the first light beam 24 can be expanded to 1:N, and the uniformity of the intensity profile of the second light beam 25 within the 85% energy range and in this dimension is greater than 0.5. In addition, the intensity distribution of the first light beam 24 along the Z direction can also be subjected to light field intensity homogenization to be nearly flat-top distribution. It can be understood that, in this embodiment, the direction of the light field intensity homogenization processing and the direction of the beam expansion processing for the first light beam 24 can be the same. For example, the light field intensity homogenization processing is performed on the first light beam 24 along the Z direction, and the beam expansion processing is also performed on the first light beam 24 along the Z direction; or, the light field intensity homogenization processing is performed on the first light beam 24 along the fourth direction, and the beam expansion processing is also performed on the first light beam 24 along the fourth direction, wherein the fourth direction is perpendicular to the X direction, and the fourth direction has an angle with the Y direction and the Z direction respectively.

[0093] Because in the third related technology, the optical system 2 also includes a motor that drives the gear device to rotate, a large amount of heat will be generated when the motor is running; and it is not easy to integrate a heat dissipation device on the reflector and the transmission mirror, which will lead to a high mirror surface temperature, thereby reducing the service life of the reflector and the transmission mirror.

[0094] In the present embodiment, after the plurality of beam expansion and homogenization units perform light field intensity homogenization processing and beam expansion processing on the first light beam 24 and obtain the second light beam 25, the energy of the second light beam 25 can be dispersed, thereby dispersing the heat, which is beneficial to the heat dissipation of the optical system 2. In this way, the situation in which the light homogenizer 22 or the beam splitter 23 in the optical system 2 is damaged due to untimely heat dissipation of the optical system 2 can be reduced, thereby increasing the service life of the light homogenizer 22 and the beam splitter 23.

[0095] In addition, if Figure 4b As shown, when multiple beam expansion and homogenization units perform light field intensity homogenization and beam expansion on the first light beam 24 and obtain the second light beam 25, the width of the second light beam 25 along the Z direction can be increased, so that the size of the beam splitter 23 that receives the second light beam 25 and splits the second light beam 25 is moderate, which facilitates the processing of the beam splitter 23.

[0096] like Figure 5 As shown, each light homogenizing unit 221 is in the shape of a long strip, and each light homogenizing unit 221 is arranged in sequence along its width direction. It can be understood that in order to enable each light homogenizing unit 221 to reflect the received first light beam 24, as shown in FIG. Figure 5As shown, the light homogenizer 22 is placed obliquely compared to the light source 21. The length direction of the light homogenizer 221 extends along the Y direction, the width direction of the light homogenizer 221 has an angle with the X direction, and the width direction of the light homogenizer 211 also has an angle with the Z direction.

[0097] The light homogenizing unit 221 has a first mirror 223 for receiving the first light beam 24 and emitting the second light beam 25. Figure 6a As shown, the first mirror surface 223 may be a cylindrical surface or a spherical surface. Figure 6b As shown, the first mirror surface 223 may also be a free-form surface.

[0098] With respect to the structure of the light homogenizer 22, in a possible embodiment, the light homogenizer 22 may be an integrally formed structure, that is, a plurality of first mirror surfaces 223 arranged in a straight line are processed on a raw material. In another possible embodiment, each light homogenizer unit 221 may be processed separately, and each light homogenizer unit 221 may be spliced ​​into the light homogenizer 22. In another possible embodiment, a plurality of light homogenizer unit assemblies may be processed, and the light homogenizer unit assembly includes at least two light homogenizer units 221, and then each light homogenizer unit assembly is spliced ​​into the light homogenizer 22. In another possible embodiment, at least one light homogenizer unit 221 may be processed, and at least one light homogenizer unit assembly may be processed, and at least one light homogenizer unit 221 and at least one light homogenizer unit assembly may be spliced ​​into the light homogenizer 22.

[0099] The radius of curvature R1 of the first mirror 223 satisfies: 5mm≤R1≤10000mm. If the radius of curvature R1 of the first mirror 223 is less than 5mm, the divergence angle of the second light beam 25 reflected from the first mirror 223 is large. In order to ensure that the beam splitter 23 can receive the second light beam 25, the size of the beam splitter 23 needs to be set to a larger size, which increases the cost of the beam splitter 23. If the radius of curvature R1 of the first mirror 223 is greater than 10000mm, the size of the light homogenizing unit 221 is too large, which will cause the size of the optical system 2 to be too large. Therefore, when the radius of curvature R1 of the first mirror 223 satisfies 5mm≤R1≤10000mm, the size of the optical system 2 will not be too large.

[0100] The number m1 of the light homogenizing units 221 satisfies: 5≤m1≤1000. Since each light homogenizing unit 221 can improve the jitter of the part of the first light beam 24 in the process of receiving the part of the first light beam 24 emitted by the light source 21 and emitting the part of the second light beam 25, and the more the number m1 of the light homogenizing units 221 is, the better the improvement effect on the jitter of the first light beam 24 is. Therefore, if the number m1 of the light homogenizing units 221 is less than 5, the improvement effect of the jitter of the first light beam 24 by each light homogenizing unit 221 is poor, that is, the second light beam 25 still has a large jitter. If the number m1 of the light homogenizing units 221 is greater than 1000, the size of the light homogenizing member 22 is larger, thereby causing the size of the optical system 2 to be larger. Therefore, when the number m1 of the light homogenizing units 221 satisfies: 5≤m1≤1000, the improvement effect on the jitter of the first light beam 24 can be maintained while avoiding increasing the size of the optical system 2.

[0101] like Figure 3 As shown, the length L1 of the light homogenizing unit 221 satisfies: 5mm≤L2≤100mm; Figure 6a As shown, the width L2 of the light homogenizing unit 221 satisfies: 1mm≤L1≤10mm. The length direction of the light homogenizing unit 221 is perpendicular to the Y direction. If the length L1 of the light homogenizing unit 221 is less than 5mm, and the width L2 of the light homogenizing unit 221 is less than 1mm, the size of the light homogenizing unit 221 is too small to be easily processed, and the processing accuracy is low; if the length L1 of the light homogenizing unit 221 is greater than 100mm, and the width L2 of the light homogenizing unit 221 is greater than 10mm, the size of the light homogenizing unit 221 is too large, thereby causing the size of the optical system 2 to be too large. Therefore, when the length L1 of the light homogenizing unit 221 satisfies: 5mm≤L2≤100mm, and the width L2 of the light homogenizing unit 221 satisfies: 1mm≤L1≤10mm, the size of the light homogenizing unit 221 is moderate, which can not only ensure the processing accuracy of the light homogenizing unit 221, but also avoid increasing the size of the optical system 2.

[0102] The normal lines of the first mirror surface 223 of each light homogenizing unit 221 are parallel, that is, the normal lines of the first mirror surface 223 of each adjacent light homogenizing unit 221 are parallel. In this way, it is convenient to uniformly manufacture each light homogenizing unit 221, thereby making the manufacture of the light homogenizing element 22 more convenient and simple.

[0103] In this embodiment, if Figure 5 As shown, a plurality of channels 222 are provided inside the light homogenizer 22. In actual use of the optical system 2, the light homogenizer 22 generates heat, and the plurality of channels 222 facilitate heat dissipation, thereby reducing the possibility of damage to the light homogenizer 22 due to untimely heat dissipation, thereby extending the service life of the light homogenizer 22.

[0104] The multiple flow channels 222 may be interconnected or parallel to each other. Figure 5 As shown, the flow channel 222 can be provided on the side of the light homogenizer 22 and penetrate from one side to another side. The flow channel 222 can also be provided on the bottom surface of the light homogenizer 22 and communicate with the side of the light homogenizer 22.

[0105] like Figure 7 As shown, the beam splitter 23 includes a plurality of beam splitting units 231. With respect to the arrangement of the plurality of beam splitting units 231, in a possible embodiment, the plurality of beam splitting units 231 are arranged in a straight line. Each beam splitting unit 231 is in the shape of an elongated strip. The orthographic projection shape of the mirror surface of the beam splitting unit 231 is a rectangle. Each beam splitting unit 231 is arranged in sequence along its width direction. Since the plurality of beam splitting units 231 are arranged in a straight line, the optical component 3 for receiving the sub-beam 26 emitted by each beam splitting unit 231 can also be arranged in a straight line. For example, in the present embodiment, the plurality of beam splitting units 231 are arranged in the Z direction and the second light beam 25 is split in the Z direction, that is, the beam splitting direction is the same as the beam expansion direction.

[0106] In another possible implementation, the plurality of beam splitting units 231 are arranged in a rectangular array. The orthographic projection shape of the mirror surface of each beam splitting unit 231 may be a square, a circle, or a rectangle with a small difference between the long side and the short side.

[0107] Moreover, if Figure 7 As shown, the beam splitting unit 231 has a second mirror 2311 for receiving the second light beam 25, and the second mirror 2311 of any beam splitting unit 231 is a cylinder, a spherical surface, a plane or a free-form surface. In one possible embodiment, the surface shape of the second mirror 2311 of each beam splitting unit 231 is the same. For example, the second mirror 2311 of each beam splitting unit 231 is a plane. This makes it easy to process the second mirror 2311 of each beam splitting unit 231 and reduces the processing cost of each beam splitting unit 231. Or, the second mirror 2311 of each beam splitting unit 231 is a cylinder. Or, the second mirror 2311 of each beam splitting unit 231 is a spherical surface. Or, the second mirror 2311 of each beam splitting unit 231 is a free-form surface. In another possible embodiment, the surface shapes of the second mirrors 2311 of some beam splitting units 231 are the same, and the surface shapes of the second mirrors 2311 of some beam splitting units 231 are different. For example, the second mirror surface 2311 of the partial beam splitting unit 231 is a cylindrical surface, and the mirror surface of the partial beam splitting unit 231 is a plane.

[0108] like Figure 7As shown, when the second mirror surface 2311 of each beam splitting unit 231 is a plane, a second angle a2 is formed between two adjacent second mirror surfaces 2311. Thus, when the second light beam 25 irradiates the plurality of beam splitting units 231, the two adjacent second mirror surfaces 2311 with the second angle a2 can reflect part of the second light beam 25 irradiated to themselves to the optical component 3 at different positions, thereby providing a sub-beam 26 for each optical component 3.

[0109] When the second mirror surface 2311 of each beam splitting unit 231 is a cylindrical surface or a spherical surface, the normal lines of the second mirror surfaces 2311 of two adjacent beam splitting units 231 have a second angle a2. In this way, when the second light beam 25 irradiates the plurality of beam splitting units 231, the two adjacent second mirror surfaces 2311 whose normal lines have the second angle a2 can reflect the part of the second light beam 25 irradiated to themselves to the optical components 3 at different positions, thereby providing a sub-beam 26 for each optical component 3.

[0110] Moreover, the second angle a2 satisfies: 0.1°≤a2≤5°. When the second angle a2 is less than 0.1°, the second angle a2 of the second mirror 2311 of two adjacent beam splitting units 231 is smaller, or the second angle a2 between the normals of the second mirror 2311 of two adjacent beam splitting units 231 is smaller, resulting in a smaller distance between the sub-beams 26 emitted by the two adjacent beam splitting units 231, resulting in a smaller distance between the optical components 3 receiving the two sub-beams 26. Since each optical component 3 also occupies a certain space, in order to meet the sufficient distance between the optical components 3, the optical components 3 need to be placed at a position far away from the beam splitter 23, which will cause the size of the optical system 2 to be too large. When the second angle a2 is greater than 5°, since the direction of the second light beam 25 incident on the beam splitter 23 is fixed, when the second angle a2 is too large, the grazing angle of the second light beam 25 incident on the partial beam splitting unit 231 will be large, and the grazing angle of reflection when the beam splitting unit 231 reflects the second light beam 25 will also be large, resulting in a low light energy utilization rate of the light beam. Therefore, when the second angle a2 satisfies: 0.1°≤a2≤5°, the second angle a2 is moderate, which can avoid the optical system 2 from being too large in size and the low light energy utilization rate.

[0111] like Figure 7As shown, the grazing angle σ of the second light beam 25 incident on the beam splitter 23 satisfies: 0.1°≤σ≤30°. When the grazing angle σ is less than 0.1°, it indicates that the grazing angle σ is too small, and the reflection function of the beam splitter 23 cannot be achieved. When the grazing angle σ is greater than 30°, the grazing reflection angle when the beam splitting unit 231 reflects the second light beam 25 is also large, resulting in a low light energy utilization rate of the light beam. Therefore, when the grazing angle σ satisfies: 0.1°≤σ≤30°, the grazing angle σ is moderate, thereby avoiding the situation of low light energy utilization rate.

[0112] In this embodiment, the plurality of beam splitting units 231 include a first beam splitting unit 231 and a second beam splitting unit 231, and the relationship between the radius of curvature R2 of the first beam splitting unit 231 and the grazing angle of incidence σ1 of the second light beam 25 incident on the first beam splitting unit 231, and the radius of curvature R3 of the second beam splitting unit 231 and the grazing angle of incidence σ2 of the second light beam 25 incident on the second beam splitting unit 231 satisfies: R2:R3=(1 / σ1):(1 / σ2). When the grazing angle of incidence of the second light beam 25 incident on the first beam splitting unit 231 is small, and the grazing angle of incidence of the second light beam 25 incident on the second beam splitting unit 231 is large, if the radius of curvature of each beam splitting unit 231 is the same, the lateral area of ​​the sub-beam 26 emitted from the first beam splitting unit 231 is large, and the lateral area of ​​the sub-beam 26 emitted from the second beam splitting unit 231 is small, which will result in different lateral areas of each sub-beam 26. By setting the relationship between the radius of curvature R2 and the grazing incidence angle σ1 of the first beam splitting unit 231 and the radius of curvature R3 and the grazing incidence angle σ2 of the second beam splitting unit 231 to: R2:R3=(1 / σ1):(1 / σ2), and adjusting the radius of curvature of each beam splitting unit 231 according to the size relationship between the grazing incidence angles of the second light beam 25 incident on the beam splitting unit 231, the lateral area of ​​each sub-beam 26 can be made as similar as possible, thereby further making the far-field distribution of each sub-beam 26 approximate.

[0113] In this embodiment, if Figure 7As shown, the length L3 of the beam splitter unit 231 satisfies: 10mm≤L3≤1000mm, the width L4 of the beam splitter unit 231 satisfies: 1mm≤L4≤30mm, and the width direction of the beam splitter unit 231 is perpendicular to the first direction, and the first direction is the arrangement direction of the light source 21 and the light homogenizer 22. If the length L3 of the beam splitter unit 231 is less than 10mm, and the width L4 of the beam splitter unit 231 is less than 1mm, the size of the beam splitter unit 231 is too small and difficult to process, and the processing accuracy is low; if the length L3 of the beam splitter unit 231 is greater than 1000mm, and the width L4 of the beam splitter unit 231 is greater than 30mm, the size of the beam splitter unit 231 is too large, thereby causing the size of the optical system 2 to be too large. Therefore, when the length L3 of the beam splitter unit 231 satisfies: 10mm≤L3≤1000mm, and the width L4 of the beam splitter unit 231 satisfies: 1mm≤L4≤30mm, the size of the beam splitter unit 231 is moderate, which can not only ensure the processing accuracy of the beam splitter unit 231 but also avoid increasing the size of the optical system 2.

[0114] In this embodiment, the number m2 of the beam splitting units 231 satisfies: 2≤m2≤20. The number m2 of the beam splitting units 231 may be the same as the number of the optical components 3, that is, each optical component 3 receives the sub-beam 26 emitted by each beam splitting unit 231 in a one-to-one correspondence. When the number m2 of the beam splitting units 231 is less than 2, the number m2 of the beam splitting units 231 is 1, and the beam splitter 23 cannot achieve the beam splitting effect. When the number m2 of the beam splitting units 231 is greater than 20, the number m2 of the beam splitting units 231 is too large, and the number of optical components 3 is correspondingly too large, resulting in an overly large size of the optical system 2. Therefore, when the number m2 of the beam splitting units 231 satisfies: 2≤m2≤20, the number m2 of the beam splitting units 231 is moderate, which can not only achieve the beam splitting effect, but also avoid increasing the size of the optical system 2.

[0115] In this embodiment, if Figure 3As shown, the optical system 2 also includes a correction mirror 27, which is located between the light homogenizer 22 and the beam splitter 23, and the correction mirror 27 can be a reflector. The correction mirror 27 can be used to receive and adjust the beam direction of the second light beam 25, and emit the second light beam 25 after the beam direction is adjusted to the beam splitter 23. Or, the correction mirror 27 can be used to receive and adjust the divergence angle of the second light beam 25, and emit the second light beam 25 after the divergence angle is adjusted to the beam splitter 23. Or, the correction mirror 27 can be used to receive and adjust the beam direction and divergence angle of the second light beam 25, and emit the second light beam 25 with the beam direction and divergence angle to the beam splitter 23. In this way, it is convenient for the beam splitter 23 to receive all the second light beams 25. Moreover, since each optical component 3 has certain requirements for the incident angle of the sub-beam 26 incident on itself, when the correction mirror 27 receives the second light beam 25, it can adjust the beam direction and divergence angle of the second light beam 25 according to the incident angle requirements incident on the optical component 3.

[0116] like Figure 2 As shown, the correction mirror 27 has a third mirror surface 271 for receiving the second light beam 25, and the third mirror surface 271 is a plane, a cylinder, a spherical surface or a free-form surface. When only the beam direction of the second light beam 25 needs to be adjusted, the third mirror surface 271 can be selected as a plane, so that the processing difficulty of the correction mirror 27 is relatively low. When the beam direction and divergence angle of the second light beam 25 need to be adjusted, the third mirror surface 271 can be processed to be a cylinder, a spherical surface or a free-form surface. Moreover, the beam direction of the second light beam 25 can be adjusted by adjusting the incident angle of the second light beam 25 incident on the correction mirror 27, and the divergence angle of the second light beam 25 can be adjusted by adjusting the curvature radius of the third mirror surface 271.

[0117] In other embodiments of the present application, Figure 8 As shown, Figure 2 The difference between the illustrated embodiments lies in the structure of the beam splitter 23. In this embodiment, a plurality of beam splitting units 231 are arranged in parallel along the X direction, and there is a spacing between two adjacent beam splitting units 231 along the X direction. And a plurality of beam splitting units 231 are offset along the Z direction. That is, the position of each beam splitting unit 231 along the Z direction is different. In addition, in order to prevent the sub-beam 26 emitted from the beam splitting unit 231 close to the correction mirror 27 from affecting the reception of the second light beam 25 by the beam splitting unit 331 far away from the correction mirror 27, the position of each beam splitting unit 231 along the Y direction may also be different. In this way, a plurality of beam splitting units 231 can split the second light beam 25, and obtain multiple sub-beams 26 and send each sub-beam 26 to each optical component 3 respectively.

[0118] In other embodiments of the present application, Fig. 9 and Fig.10 As shown, Figure 2The difference between the embodiments shown in the figure lies in the positional relationship between the normal lines of the first mirror surface 223 of each light homogenizing unit 221 and ... Figure 2 The correction mirror 27 is removed on the basis of the embodiment shown. In this embodiment, the normals of the first mirrors 223 of each light homogenizing unit 221 have an angle between them. For example, the normals of the first mirrors 223 of two adjacent light homogenizing units 221 have a first angle a1 between them. In this way, the light homogenizing unit 221 can not only perform light field intensity homogenization processing on the received part of the first light beam 24, but also adjust the beam direction and / or divergence angle of the part of the first light beam 24. In this way, the number of components of the optical system 2 can be reduced, thereby reducing the cost of the optical system 2.

[0119] Moreover, the first angle a1 satisfies: a1≤2°. If the first angle a1 is greater than 2°, the grazing angle of incidence of the first light beam 24 incident on the partial light homogenizing unit 221 will be too large, so that the second light beam 25 is emitted to the area outside the beam splitter 23, that is, the second light beam 25 cannot be emitted to the beam splitter 23. Therefore, when the first angle a1 satisfies: a1≤2°, each light homogenizing unit 221 can emit the second light beam 25 to the beam splitter 23 after receiving the first light beam 24.

[0120] In other embodiments of the present application, Fig.11 As shown, Figure 8 The difference between the embodiments shown in the figure lies in the positional relationship between the normal lines of the first mirror surface 223 of each light homogenizing unit 221 and ... Figure 8 The correction mirror 27 is removed from the embodiment shown. In this embodiment, the normals of the first mirrors 223 of each light homogenizing unit 221 have an angle between them. For example, the normals of the first mirrors 223 of two adjacent light homogenizing units 221 have a first angle a1 between them. In this way, the light homogenizing unit 221 can not only perform light field intensity homogenization processing on the received part of the first light beam 24, but also adjust the beam direction and / or divergence angle of the part of the first light beam 24. In this way, the number of components of the optical system 2 can be reduced, thereby reducing the cost of the optical system 2.

[0121] Moreover, the first angle a1 satisfies: a1≤2°. If the first angle a1 is greater than 2°, the grazing angle of incidence of the first light beam 24 incident on the partial light homogenizing unit 221 will be too large, so that the second light beam 25 is emitted to the area outside the beam splitter 23, that is, the second light beam 25 cannot be emitted to the beam splitter 23. Therefore, when the first angle a1 satisfies: a1≤2°, each light homogenizing unit 221 can emit the second light beam 25 to the beam splitter 23 after receiving the first light beam 24.

[0122] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. An optical system, characterized in that: It includes a light source, a light homogenizer and a beam splitter, wherein: The light source is used to emit a first light beam; The light homogenizer includes a plurality of light homogenizer units arranged in a straight line, and the plurality of light homogenizer units are used to receive the first light beam and perform light field intensity homogenization processing on the first light beam to obtain a second light beam and emit it; The beam splitter is used to receive the second light beam and split the second light beam into a plurality of sub-beams.

2. The optical system according to claim 1, characterized in that The first light homogenizing unit is a beam expanding light homogenizing unit. The first light homogenizing unit is a light homogenizing unit among the multiple light homogenizing units. The beam expanding light homogenizing unit is specifically used to receive part of the first light beam and perform light field intensity homogenization and beam expansion processing on the part of the first light beam to obtain part of the second light beam.

3. The optical system according to claim 1 or 2, characterized in that: The light homogenizing unit has a first mirror surface for receiving the first light beam and emitting the second light beam, and the first mirror surface is a cylindrical surface, a spherical surface or a free-form surface.

4. The optical system according to claim 3, characterized in that The curvature radius R1 of the first mirror surface satisfies: 5mm≤R1≤10000mm.

5. The optical system according to any one of claims 1 to 4, characterized in that: The number m1 of the light homogenization units satisfies: 5≤m1≤1000.

6. The optical system according to any one of claims 1 to 5, characterized in that: The length L1 of the light homogenizing unit satisfies: 5mm≤L1≤100mm; the width L2 of the light homogenizing unit satisfies: 1mm≤L2≤10mm, and the length direction of the light homogenizing unit is perpendicular to the first direction, which is the arrangement direction of the light source and the light homogenizing element.

7. The optical system according to claim 3 or 4, characterized in that: Normal lines of the first mirror surfaces of two adjacent light homogenizing units are parallel.

8. The optical system according to any one of claims 1 to 7, characterized in that: The optical system further comprises a correction mirror, wherein the correction mirror is located between the light homogenizing element and the beam splitter, and the correction mirror is used to adjust the beam direction and / or divergence angle of the second light beam.

9. The optical system according to claim 3 or 4, characterized in that: There is a first angle a1 between normal lines of the first mirror surfaces of two adjacent light homogenizing units.

10. The optical system according to claim 9, characterized in that The first angle a1 satisfies: a1≤2°.

11. The optical system according to any one of claims 1 to 10, characterized in that: The light homogenizer is a reflector, and a grazing reflection angle r of the second light beam satisfies: 0.1°≤r≤20°; the grazing reflection angle r is a complementary angle of a reflection angle of the second light beam.

12. The optical system according to any one of claims 1 to 11, characterized in that: A plurality of flow channels are arranged inside the light homogenizing member.

13. The optical system according to any one of claims 1 to 12, characterized in that: The beam splitter includes a plurality of beam splitting units, and the plurality of beam splitting units are arranged along a straight line.

14. The optical system according to any one of claims 1 to 13, characterized in that: The beam splitter includes a plurality of beam splitting units, and the plurality of beam splitting units are arranged in a rectangular array.

15. The optical system according to claim 13, characterized in that The plurality of beam splitting units are arranged along a second direction, and the second direction is perpendicular to a propagation direction of the second light beam; The beam splitting unit has a second mirror surface for receiving the second light beam. The second mirror surface of each beam splitting unit is a plane, and a second angle a2 is formed between two adjacent second mirror surfaces.

16. The optical system according to claim 13, characterized in that The plurality of beam splitting units are arranged along a second direction, and the second direction is perpendicular to a propagation direction of the second light beam; The beam splitting unit has a second mirror surface for receiving the second light beam, the second mirror surface of each beam splitting unit is a cylindrical surface or a spherical surface, and the normal lines of the second mirror surfaces of two adjacent beam splitting units have a second angle a2 therebetween.

17. The optical system according to claim 15 or 16, characterized in that The second angle a2 satisfies: 0.1°≤a2≤5°.

18. The optical system according to claim 13, characterized in that The plurality of beam splitting units are arranged in parallel along a propagation direction of the second light beam, and there is a distance between two adjacent beam splitting units.

19. The optical system according to any one of claims 1 to 18, characterized in that: The grazing incidence angle σ of the second light beam incident on the beam splitter satisfies: 0.1°≤σ≤30°.

20. The optical system according to any one of claims 13 to 19, characterized in that: The multiple beam splitting units include a first beam splitting unit and a second beam splitting unit, and the relationship between the curvature radius R2 of the first beam splitting unit and the grazing incidence angle σ1 of the second light beam incident to the first beam splitting unit, and the relationship between the curvature radius R3 of the second beam splitting unit and the grazing incidence angle σ2 of the second light beam incident to the second beam splitting unit satisfies: R2:R3=(1 / σ1):(1 / σ2).

21. The optical system according to any one of claims 13 to 20, characterized in that: The length L3 of the beam splitter unit satisfies: 10mm≤L3≤1000mm, the width L4 of the beam splitter unit satisfies: 1mm≤L4≤30mm, and the width direction of the beam splitter unit is perpendicular to the first direction, which is the arrangement direction of the light source and the light homogenizer.

22. An optical system according to any one of claims 13 to 18, 20 or 21, characterized in that: The number m2 of the beam splitting units satisfies: 2≤m2≤20.

23. An optical device, characterized in that: The optical system comprises a plurality of optical components and any one of claims 1 to 22, wherein the optical system is used to send a sub-beam to each of the optical components respectively.

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