Light detection modulation device and lighting system

Abstract

The present invention relates to the technical field of optical detection, and in particular to a detection light modulation device and an illumination system. The detection light modulation device is used to be arranged between a light source and a diffractive optical element. The illumination light emitted by the light source is modulated by the detection light modulation device and the diffractive optical element in sequence to form a long-strip-shaped light spot on the sample to be detected. Among them, the illumination light emitted by the light source is modulated into a target light beam by the detection light modulation device. Along the length direction of the long-strip-shaped light spot, the light intensity of the target light beam is Gaussian distributed, so that the light intensity of the long-strip-shaped light spot is flat-top distributed. The detection light modulation device at least includes an image rotation component. Along a first preset direction, the light intensity of the illumination light is Gaussian distributed. The image rotation component is used to rotate the illumination light so that the first preset direction coincides with the length direction of the long-strip-shaped light spot. The present invention is at least beneficial to improving the stability of the detection light.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical detection, and in particular relates to a detection light modulation device and an illumination system. Background Art

[0002] The lighting system is one of the important components of wafer inspection equipment. In the lighting system, the illumination light emitted by the light source is generally modulated into detection light through a diffractive optical element. The diffractive optical element modulates the circular light spot emitted by the laser or other light source, which ideally conforms to the Gaussian distribution, into a linear illumination light spot (long strip light spot) at the illumination position. However, the flat-top light modulated and shaped by the diffractive optical element on the incident light cannot achieve a better beam shaping effect, has poor uniformity, and the light spot distribution deviates from the designed state, which seriously affects the detection accuracy.

[0003] Therefore, how to optimize the spot distribution of the linear illumination spot and thereby improve the wafer detection accuracy has become an urgent problem to be solved in the current lighting system. Summary of the invention

[0004] In view of this, the present invention aims to provide a detection light modulation device and an illumination system, which are at least beneficial to improving the stability of the detection light.

[0005] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0006] The invention provides a detection light modulation device, comprising: a detection light modulation device used to be arranged between a light source and a diffractive optical element, wherein the illumination light emitted by the light source is modulated by the detection light modulation device and the diffractive optical element in sequence to form a long strip light spot on a sample to be inspected; wherein the illumination light emitted by the light source is modulated into a target light beam by the detection light modulation device, and along the length direction of the long strip light spot, the light intensity of the target light beam is Gaussian distributed, so that the light intensity of the long strip light spot is flat-top distributed; the detection light modulation device at least comprises an image rotation component, and along a first preset direction, the light intensity of the illumination light is Gaussian distributed, and the image rotation component is used to rotate the illumination light, so that the first preset direction coincides with the length direction of the long strip light spot.

[0007] Furthermore, the detection light modulation device also includes a variable magnification lens assembly, the variable magnification lens assembly and the image rotation assembly are arranged along the light beam transmission direction, and the variable magnification lens assembly is used to adjust the size of the illumination light so that along the first preset direction, the size of the target light beam is a first target size.

[0008] Furthermore, the image rotation assembly and the zoom lens assembly are arranged in sequence along the light beam transmission direction.

[0009] Furthermore, the image rotation component is also used to adjust the light beam divergence angle to a target divergence angle so that the width of the long strip light spot is the target width.

[0010] Further, the zoom lens group includes a plurality of convex-concave lenses, and the distance between any two adjacent convex-concave lenses is adjustable.

[0011] Further, the zoom lens group includes three convex-concave lenses.

[0012] Further, along the length direction of the elongated light spot, the uniformity parameter a of the light intensity of the elongated light spot is greater than 90%, a = 1 - (max - min) / (max + min), where max is the maximum value of the light intensity of the elongated light spot, and min is the minimum value of the light intensity within the distribution region of the elongated light spot.

[0013] Further, the detection light modulation device further includes a polarization adjustment component, which is located between the image rotation component and the light source, and the polarization adjustment component is used to adjust the polarization direction of the illumination light so that the polarization direction of the target light beam is the target polarization direction.

[0014] Further, the polarization adjustment component includes a plurality of rotatable wave plates arranged along the optical path direction.

[0015] Further, the polarization adjustment component includes: a half-wave plate and a first electric turntable, the half-wave plate is arranged on the first electric turntable, and the first electric turntable can drive the half-wave plate to rotate along the optical axis; a quarter-wave plate and a second electric turntable, the quarter-wave plate is arranged on the second electric turntable, and the second electric turntable can drive the quarter-wave plate to rotate along the optical axis.

[0016] Further, the image rotation component includes an image rotation structure and a third electric turntable, the image rotation structure is arranged on the third electric turntable, and the third electric turntable can drive the image rotation structure to rotate along the optical axis.

[0017] Further, the image rotation structure includes a Dove prism.

[0018] On the other hand, the present invention provides an illumination system, including: a light source, a diffractive optical element, and the detection light modulation device according to any one of the above; wherein, the detection light modulation device is arranged between the light source and the diffractive optical element, the illumination light emitted by the light source is modulated by the detection light modulation device and the diffractive optical element in sequence to form an elongated light spot on the sample to be detected, the illumination light emitted by the light source is modulated by the detection light modulation device to form a target light beam, and along the length direction of the elongated light spot, the light intensity of the target light beam is Gaussian distributed so that the light intensity of the elongated light spot is flat-top distributed.

[0019] Further, the illumination system further includes: a circular spot sampling mirror and a circular spot monitoring camera, wherein the circular spot sampling mirror can be inserted into the optical path between the detection light modulation device and the diffractive optical element to guide the target light beam to the circular spot monitoring camera for imaging.

[0020] Further, the illumination system further includes: a line spot sampling mirror and a line spot monitoring camera, wherein the line spot sampling mirror is configured to guide the detection light emitted by the diffractive optical element to the line spot monitoring camera for imaging the elongated light spot.

[0021] Compared with the prior art, the present invention can achieve the following beneficial effects: when the illumination light emitted by the light source changes, that is, it does not completely conform to the Gaussian distribution state, the detection light modulation device provided by the present invention is used to adjust the illumination light into a target beam, and the light spot corresponding to the target beam adapts to the incident conditions of the diffractive optical element, so that the target beam forms a line illumination light spot with core parameters meeting the requirements after being modulated by the diffractive optical element. The core parameters may include the shape and light intensity distribution state of the line illumination light spot. Even if the beam state emitted by the light source changes, the core parameters of the line illumination light spot are always ensured to be unchanged, which is beneficial to improving the light spot uniformity and morphology consistency of the detection light and ensuring the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which form a part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0023] Figure 1 is a schematic structural diagram of the illumination system according to the embodiment of the present invention;

[0024] Figure 2 is a schematic diagram of different types of illumination light and their corresponding elongated light spots according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] After analysis, it is found that the line illumination light spot generally mainly has parameter requirements for morphology distribution, outer dimension, and polarization state, and the design and processing of the diffractive optical element generally can only correspond to one incident condition. When the actual incident condition changes, that is, when the incident light spot does not completely conform to the Gaussian distribution state, the diffractive optical element cannot achieve the same modulation effect as the designed condition.

[0026] To solve the above problems, the present invention provides a detection light modulation device for being disposed in an illumination system, which can always ensure that the core parameters of the line illumination light spot remain unchanged when the beam state emitted by the light source changes, is beneficial to improving the light spot uniformity and morphology consistency of the detection light, and ensures the detection accuracy.

[0027] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following further describes the present invention in detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention.

[0028] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0029] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present invention. In addition, terms such as "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the technical features indicated. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0030] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0031] The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0032] Reference Figure 1 , on the one hand, the present invention provides a detection light modulation device for being arranged in an illumination system. Specifically, the detection light modulation device is for being arranged between a light source 10 and a diffractive optical element 19. The illumination light emitted by the light source 10 is modulated by the detection light modulation device and the diffractive optical element 19 in sequence to form a long strip-shaped light spot 22 on the sample to be detected. The purpose of the detection light modulation device provided by the present invention is to modulate the illumination light deviating from the standard into a light beam that meets the incident conditions of the diffractive optical element 19. It should be noted that the incident conditions of the same diffractive optical element 19 are unchanged. Only by ensuring that the light beam incident on the diffractive optical element 19 meets the incident conditions of the diffractive optical element 19 can it be ensured that the diffractive optical element 19 forms a standard long strip-shaped light spot 22 on the sample to be detected.

[0033] In some examples, the sample to be detected can be a wafer, and the light source 10 can include a laser.

[0034] Specifically, the illumination light emitted by the light source 10 is modulated by the detection light modulation device into a target beam, and the target beam is a beam that meets the incident conditions of the diffractive optical element 19. The light intensity distribution of the standard long strip-shaped light spot 22 is usually a flat-top distribution. In order to diffract the standard long strip-shaped light spot 22, the target beam needs to meet the following conditions: along the length direction of the long strip-shaped light spot 22, the light intensity of the target beam is in a Gaussian distribution, so that the light intensity of the long strip-shaped light spot 22 is in a flat-top distribution.

[0035] To achieve the above object, the detection light modulation device provided by the present invention at least includes an image rotation component 13. Along the first preset direction, the light intensity of the illumination light is in a Gaussian distribution. The image rotation component 13 is used to rotate the illumination light so that the first preset direction coincides with the length direction of the long strip-shaped light spot 22. That is to say, when the illumination light satisfies that along the first preset direction, the light intensity of the illumination light is in a Gaussian distribution, but along the length direction of the long strip-shaped light spot 22, the light intensity of the illumination light does not satisfy the Gaussian distribution (that is, there is an included angle between the first preset direction and the length direction of the long strip-shaped light spot 22), the image rotation component 13 can be used to rotate the illumination light so that the first preset direction rotates to coincide with the length direction of the long strip-shaped light spot 22. It can also be said that along the length direction of the long strip-shaped light spot 22, the rotated illumination light (target beam) is in a Gaussian distribution. In this way, along the length direction of the long strip-shaped light spot 22, the light intensity of the long strip-shaped light spot 22 can be in a flat-top distribution, meeting the requirements of the standard long strip-shaped light spot 22.

[0036] In some embodiments, the detection light modulation device further includes a zoom lens assembly 24. The zoom lens assembly 24 and the image rotation component 13 are arranged along the beam transmission direction. The zoom lens assembly 24 is used to adjust the size of the illumination light so that along the first preset direction, the size of the target beam is the first target size. The reason for such a setting is as follows: for the standard long strip-shaped light spot 22, the flat-top distribution of the light intensity of the long strip-shaped light spot 22 needs to meet the requirement that the uniformity parameter a of the light intensity is greater than a preset value. If the size of the beam incident on the diffractive optical element 19 in the length direction of the long strip-shaped light spot 22 does not meet the requirements, then the light intensity of the long strip-shaped light spot 22 formed after passing through the diffractive optical element 19 does not meet the requirement that the uniformity parameter a of the light intensity is greater than the preset value. To solve this problem, by setting the zoom lens assembly 24, the beam incident on the diffractive optical element 19 is magnified or reduced so that the size of the target beam in the length direction of the long strip-shaped light spot 22 meets the incident conditions of the diffractive optical element 19, and further the uniformity parameter a of the light intensity of the long strip-shaped light spot 22 is greater than the preset value.

[0037] For the standard elongated light spot 22, in some embodiments, its flat-top distribution satisfies that along the length direction of the elongated light spot 22, the uniformity parameter a of the light intensity of the elongated light spot 22 is greater than 90%, and a = 1 - (max - min) / (max + min), where max is the maximum value of the light intensity of the elongated light spot 22, and min is the minimum value of the light intensity within the distribution area of the elongated light spot 22.

[0038] In some embodiments, the image rotation assembly 13 and the zoom lens assembly 24 are arranged in sequence along the beam transmission direction. It should be noted that when the illumination light emitted by the light source 10 meets the incident conditions of the diffractive optical element 19, both the image rotation assembly 13 and the zoom lens assembly 24 are in the zero position. That is to say, the detection light modulation device does not play a modulation role, and the target beam is the illumination beam, and the transmission direction of the target beam is the same as that of the illumination beam. When the illumination light emitted by the light source 10 does not meet the incident conditions of the diffractive optical element 19, the image rotation assembly 13 and the zoom lens assembly 24 may both deviate from the zero position to modulate the illumination light. The image rotation assembly 13 and the zoom lens assembly 24 are arranged in sequence along the beam transmission direction, which is beneficial to ensuring that the transmission direction of the target beam formed after the illumination light is modulated by the image rotation assembly 13 and the zoom lens assembly 24 is the same as the original optical path of the illumination light.

[0039] In some embodiments, the image rotation assembly 13 is further configured to adjust the beam divergence angle to a target divergence angle so that the width of the elongated light spot 22 is the target width. The reason for this setting is that for the standard elongated light spot 22, there may be width requirements. For example, the width of the standard elongated light spot 22 is the first width. If the beam divergence angle of the target beam does not meet the requirements, the width of the elongated light spot 22 formed after passing through the diffractive optical element 19 is not equal to the first width either. To solve this problem, by adjusting the beam divergence angle through the zoom lens assembly 24, the beam divergence angle of the target beam is the target divergence angle, and thus an elongated light spot 22 with the first width can be formed. It should be noted that the target divergence angle is determined according to the first width, and the embodiments of the present invention do not limit the target divergence angle and the first width.

[0040] In some embodiments, the zoom lens group includes a plurality of convex-concave lenses, and the distance between any two adjacent convex-concave lenses is adjustable. By adjusting the distance, two functions can be achieved. One is to scale the beam within a certain range, and the other is to control the divergence angle of the transmitted beam within a certain range.

[0041] In some embodiments, the zoom lens group includes three convex-concave lenses, which are the first convex-concave lens 14, the second convex-concave lens 15, and the third convex-concave lens 16 respectively.

[0042] In some embodiments, the detection light modulation device further includes a polarization adjustment component 23, which is located between the image rotation component 13 and the light source 10. The polarization adjustment component 23 is used to adjust the polarization direction of the illumination light so that the polarization direction of the target light beam is the target polarization direction.

[0043] In some embodiments, the polarization adjustment component 23, the image rotation component 13, and the zoom lens component 24 are arranged in sequence along the light beam transmission direction. In other embodiments, the polarization adjustment component 23, the zoom lens component 24, and the image rotation component 13 are arranged in sequence along the light beam transmission direction.

[0044] In some embodiments, the polarization adjustment component 23 includes a plurality of rotatable wave plates arranged along the optical path direction.

[0045] In some embodiments, the polarization adjustment component 23 includes: a 1 / 2 wave plate 11 and a first electric turntable. The 1 / 2 wave plate 11 is disposed on the first electric turntable, and the first electric turntable can drive the 1 / 2 wave plate 11 to rotate along the optical axis; a 1 / 4 wave plate 12 and a second electric turntable. The 1 / 4 wave plate 12 is disposed on the second electric turntable, and the second electric turntable can drive the 1 / 4 wave plate 12 to rotate along the optical axis.

[0046] It should be noted that the arrangement order of the rotatable 1 / 2 wave plate 11 and the rotatable 1 / 4 wave plate 12 can be that the 1 / 2 wave plate 11 is located between the 1 / 4 wave plate 12 and the light source 10, or the 1 / 4 wave plate is located between the 1 / 2 wave plate and the light source 10.

[0047] In some embodiments, the image rotation component 13 includes an image rotation structure and a third electric turntable. The image rotation structure is disposed on the third electric turntable, and the third electric turntable can drive the image rotation structure to rotate along the optical axis.

[0048] It should be noted that the optical axis in the present invention refers to the optical axis of the illumination light.

[0049] In some embodiments, the image rotation structure includes a Dove prism.

[0050] Next, based on the detection light modulation device provided by the present invention, the relationship between the illumination light and the long strip-shaped light spot will be described in detail.

[0051] Reference Figure 2 , Figure 2 In (a) of, the light spot corresponding to the illumination light with an ideal light intensity distribution (referred to as the ideal Gaussian distribution illumination light) (abbreviation: ideal Gaussian distribution illumination spot), and the intensity distributions in the vertical and horizontal directions of the ideal Gaussian distribution illumination spot are both standard Gaussian distributions.

[0052] For the detection optical modulation device provided by the present invention, when the spot corresponding to the illumination light is an ideal Gaussian distribution illumination spot with a polarization direction meeting the requirements, the polarization adjustment component 23 is in the zero position, that is, the polarization adjustment component 23 does not change the polarization direction of the transmitted beam, and the image rotation structure is also in the zero position, that is, it does not change the rotation direction of the transmitted beam. If the size of the ideal Gaussian distribution illumination spot also meets the requirements, the zoom lens group is also in the zero position, that is, it does not adjust the size of the ideal Gaussian distribution illumination spot. It can be understood that if the size of the ideal Gaussian distribution illumination spot does not meet the requirements, the zoom lens group needs to be used to adjust the size of the ideal Gaussian distribution illumination spot to the spot size that meets the incident conditions of the diffractive optical element 19, so that the light intensity distribution and size of the target beam obtained through the detection optical modulation device are both consistent with the incident conditions of the diffractive optical element 19, and further, after the target beam passes through the diffractive optical element 19, an ideal standard line illumination spot as shown in (d) of Figure 2 can be obtained.

[0053] According to the foregoing embodiments, in some embodiments, the uniformity parameter a of the light intensity of the standard long strip spot 22 can be greater than 90%. The uniformity distribution of the light intensity of the long strip spot 22 depends on the distribution state of the light intensity of the beam incident on the diffractive optical element 19 in the vertical direction and the size of the beam incident on the diffractive optical element 19 in the vertical direction. The vertical direction here is the length direction of the long strip spot 22. In addition, the design target value of the transverse width of the standard long strip spot 22 is also a fixed value.

[0054] Figure 2 In, the darker the color, the stronger the intensity. Figure 2 The light intensity in the middle of the long strip spot 22 shown in (e) of Figure 2 is strong and weak at both ends.

[0055] The color corresponding to the light intensity of the long strip spot 22 shown in (d) of Figure 2 can be basically unchanged in the illumination area, indicating that the spot uniformity is good and it shows a flat-top distribution. Figure 2As shown in (e) thereof, after passing through the diffractive optical element 19, the intensity of the obtained strip-shaped light spot 22 is abnormally distributed in the length direction of the strip-shaped light spot 22, and the uniformity parameter a of the light intensity is small. The transverse width of the strip-shaped light spot 22 also deviates from the designed target value, and the strip-shaped light spot 22 fails to meet the standard, and thus the ideal illumination condition cannot be achieved for the sample to be detected.

[0056] Reference Figure 2 in (c) and Figure 2 in (f), if the detection light modulation device provided by the present invention is adopted, a Dove prism (or other image rotation structure) is used to rotate the direction of the illumination light, and the direction in which the intensity conforms to the Gaussian distribution is rotated to the vertical direction to align with the length direction of the strip-shaped light spot 22. After the alignment, the variable magnification lens assembly 24 adjusts the magnification according to the spot size in the vertical direction, so that the size of the outgoing light spot in the vertical direction meets the incident condition of the diffractive optical element 19, forming a light spot as shown in Figure 2 in (c). Under such conditions, after the light beam passes through the diffractive optical element 19, a strip-shaped light spot 22 as shown in Figure 2 in (f) is formed. The uniformity parameter a of the light intensity of the obtained strip-shaped light spot 22 is greater than 90%. In addition, the transverse width of the strip-shaped light spot 22 can be controlled by adjusting the beam divergence angle of the variable magnification lens assembly to the designed target divergence angle.

[0057] In some embodiments, during the dark-field optical inspection of a wafer, when facing wafers with different types of defects or different materials, it is necessary to configure and switch the polarization state of the detection light. The detection light carrying polarization information is scattered by the surface of the sample to be detected, processed by the imaging system, and enters the detection camera for signal acquisition and analysis. Therefore, the present invention uses the polarization adjustment component 23 to precisely control the polarization state of the detection light to achieve the configuration and switching of the polarization state of the detection light.

[0058] In some embodiments, when the image rotation component 13 is enabled, as the direction of the light beam rotates, the polarization direction of the light beam also changes. In order to control the polarization direction unchanged, polarization rotation compensation can be performed through the polarization adjustment component 23 to ensure that the polarization state of the light beam does not change significantly after the image rotation component 13 is enabled.

[0059] In some embodiments, the polarization adjustment component 23 is used to control the state of the light beam entering the image rotation component 13 to be a linearly polarized state. The advantages of adjusting to the linearly polarized state include: the linearly polarized state is the main polarization state used in dark-field detection; the linearly polarized state has a definite output result when used in combination with the analyzer module, and this combination is an important part in dark-field detection; the linearly polarized state can be relatively easily converted into other polarization states through a certain combination of wave plates when necessary.

[0060] On the other hand, the present invention provides an illumination system, comprising: a light source 10, a diffractive optical element 19, and the detection light modulation device of any one of the above; wherein, the detection light modulation device is disposed between the light source 10 and the diffractive optical element 19, and the illumination light emitted by the light source 10 is modulated by the detection light modulation device and the diffractive optical element 19 in sequence to form a strip-shaped light spot 22 on the sample to be detected. The illumination light emitted by the light source 10 is modulated by the detection light modulation device to form a target beam. Along the length direction of the strip-shaped light spot 22, the light intensity of the target beam is Gaussian distributed so that the light intensity of the strip-shaped light spot 22 is flat-topped distributed.

[0061] It should be noted that for the detection light modulation device, the specific content can be referred to the foregoing embodiments and will not be elaborated herein.

[0062] In some embodiments, the illumination system further comprises: a circular light spot sampling mirror 17 and a circular light spot monitoring camera 18. Wherein, the circular light spot sampling mirror 17 can be inserted into the optical path between the detection light modulation device and the diffractive optical element 19 to guide the target beam to the circular light spot monitoring camera 18 for imaging. The circular light spot monitoring camera 18 is used to monitor the spot morphology of the target beam modulated by the detection light modulation device in real time. The circular light spot sampling mirror 17 can collect the light beam in the way of lens light leakage or sampling mirror. As Figure 1 shown, the circular light spot sampling mirror 17 is located in front of the diffractive optical element 19 and can accurately reflect the beam distribution of the light beam entering the diffractive optical element 19.

[0063] In some embodiments, the illumination system further comprises: a linear light spot sampling mirror 21 and a linear light spot monitoring camera 20. Wherein, the linear light spot sampling mirror 21 is used to guide the detection light emitted by the diffractive optical element 19 to the linear light spot monitoring camera 20 to image the strip-shaped light spot 22. The linear light spot monitoring camera 20 can be used to monitor the morphology of the strip-shaped light spot 22 formed by the diffractive optical element 19 in real time. The linear light spot sampling mirror 21 is located behind the diffractive optical element 19, and the acquisition position of the linear light spot monitoring camera 20 is equivalent to the actual illumination position of the strip-shaped light spot 22, and thus can accurately reflect the morphology of the strip-shaped light spot 22.

[0064] By using the illumination system provided by the present invention, different-shaped illumination lights can be uniformly converted into standard strip-shaped light spots 22 that meet the requirements without replacing the light source 10 and the diffractive optical element 19. Specifically, the detection light modulation device is used to adjust the non-ideal illumination light emitted by the light source 10 into a target beam adapted to the incident conditions of the diffractive optical element 19. When the illumination light changes, the detection light modulation device is used to keep the core parameters of the strip-shaped light spot 22 modulated by the diffractive optical element 19 unchanged, which is beneficial to improving the stability of the detection light.

[0065] It should be understood that the various forms of processes shown above can be used, with steps reordered, added or deleted. For example, the steps described in the disclosure of the present invention can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and no limitation is imposed herein.

[0066] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A light modulation device for detection, characterized in that, Comprising: The detection light modulation device is used to be arranged between a light source and a diffractive optical element. The illumination light emitted by the light source is modulated by the detection light modulation device and the diffractive optical element in sequence to form a long-strip-shaped light spot on the sample to be detected; Wherein, the illumination light emitted by the light source is modulated by the detection light modulation device into a target light beam adapted to the incident conditions of the diffractive optical element. Along the length direction of the long-strip-shaped light spot, the light intensity of the target light beam is Gaussian-distributed, so that the light intensity of the long-strip-shaped light spot is flat-top-distributed; The detection light modulation device at least includes an image rotation component. When the illumination light emitted by the light source meets the incident conditions of the diffractive optical element, the image rotation component is in the zero position. When the light intensity of the illumination light is Gaussian-distributed along a first preset direction and the light intensity of the illumination light does not meet the Gaussian distribution along the length direction of the long-strip-shaped light spot, the image rotation component is used to rotate the illumination light so that the first preset direction coincides with the length direction of the long-strip-shaped light spot.

2. The detection optical modulation device according to claim 1, characterized in that, The detection light modulation device further includes a variable magnification lens component. The variable magnification lens component and the image rotation component are arranged along the light beam transmission direction. The variable magnification lens component is used to adjust the size of the illumination light so that the size of the target light beam is a first target size along the first preset direction.

3. The detection optical modulation device according to claim 2, wherein The image rotation component and the variable magnification lens component are arranged in sequence along the light beam transmission direction.

4. The detection optical modulation device according to claim 2, wherein The image rotation component is further used to adjust the beam divergence angle to a target divergence angle so that the width of the long-strip-shaped light spot is a target width.

5. The detection optical modulation device according to claim 2, wherein The variable magnification lens group includes a plurality of convex-concave lenses, and the distance between any two adjacent convex-concave lenses is adjustable.

6. The detection optical modulation device according to claim 5, wherein The variable magnification lens group includes three convex-concave lenses.

7. The detection optical modulation device according to claim 1, wherein Along the length direction of the long-strip-shaped light spot, the uniformity parameter a of the light intensity of the long-strip-shaped light spot is greater than 90%, a = 1 - (max - min) / (max + min), where max is the maximum value of the light intensity of the long-strip-shaped light spot and min is the minimum value of the light intensity within the distribution area of the long-strip-shaped light spot.

8. The optical modulation device for detection according to any one of claims 1 to 6, characterized in that The detection light modulation device further includes a polarization adjustment component. The polarization adjustment component is located between the image rotation component and the light source. The polarization adjustment component is used to adjust the polarization direction of the illumination light so that the polarization direction of the target light beam is a target polarization direction.

9. The detection optical modulation device according to claim 8, wherein The polarization adjustment component includes a plurality of rotatable wave plates arranged along the optical path direction.

10. The detection optical modulation device according to claim 9, characterized in that, The polarization adjustment component includes: A 1 / 2 wave plate and a first electric turntable. The 1 / 2 wave plate is arranged on the first electric turntable, and the first electric turntable can drive the 1 / 2 wave plate to rotate along the optical axis; A 1 / 4 wave plate and a second electric turntable. The 1 / 4 wave plate is arranged on the second electric turntable, and the second electric turntable can drive the 1 / 4 wave plate to rotate along the optical axis.

11. The detection optical modulation device according to claim 1, wherein, The image rotation component includes an image rotation structure and a third electric turntable. The image rotation structure is arranged on the third electric turntable, and the third electric turntable can drive the image rotation structure to rotate along the optical axis.

12. The detection optical modulation device according to claim 11, characterized in that, The image rotation structure includes a Dove prism.

13. A lighting system, characterized in that, Comprising: A light source, a diffractive optical element, and the detection light modulation device according to any one of claims 1 to 12; Wherein, the detection light modulation device is arranged between the light source and the diffractive optical element, and the illumination light emitted by the light source is modulated by the detection light modulation device and the diffractive optical element in sequence to form a long-strip-shaped light spot on the sample to be detected. The illumination light emitted by the light source is modulated by the detection light modulation device to form a target beam. Along the length direction of the long-strip-shaped light spot, the light intensity of the target beam is Gaussian-distributed, so that the light intensity of the long-strip-shaped light spot is flat-top-distributed.

14. The lighting system according to claim 13, characterized in that, The illumination system further includes: a circular light spot sampling mirror and a circular light spot monitoring camera, wherein the circular light spot sampling mirror can be cut into the optical path between the detection light modulation device and the diffractive optical element to guide the target beam to the circular light spot monitoring camera for imaging.

15. The lighting system according to claim 13, characterized in that, The illumination system further includes: a linear light spot sampling mirror and a linear light spot monitoring camera, wherein the linear light spot sampling mirror is used to guide the detection light emitted by the diffractive optical element to the linear light spot monitoring camera to image the long-strip-shaped light spot.

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