Polarization optical microscopic measurement system

Abstract

The utility model discloses a polarized optical microscopic measurement system which comprises a light source, a first polarization group, a sample holder, an objective lens, an infinite correction tube lens, a two-dimensional adjustable slit, an imaging lens group and a signal collector. The first polarization group is arranged in the light propagation direction of the light source, the sample holder is arranged on the side, away from the light source, of the first polarization group, the objective lens is arranged on the side, away from the first polarization group, of the sample holder, the infinite correction tube lens is arranged on the side, away from the sample holder, of the objective lens, and the two-dimensional adjustable slit is arranged on the side, away from the objective lens, of the infinite correction tube lens. The imaging lens group is arranged on the side, away from the infinite correction tube lens, of the two-dimensional adjustable slit, and the signal collector is arranged on the side, away from the two-dimensional adjustable slit, of the imaging lens group. According to the polarized optical microscopic measurement system provided by the embodiment of the utility model, the optical elements are arranged in a line to form a line-shaped in-line light path, so that the optical test of polarization spectrum and polarization imaging of a micro-nano structure is realized, and the test efficiency and accuracy are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of microscopic measurement, and in particular relates to a polarization optical microscopic measurement system. Background Art

[0002] Polarization is an important property of light that can reflect the characteristics of materials and structures. Polarization analysis can obtain the two-dimensional spatial distribution information of the test sample, as well as polarization characteristic parameters such as polarization degree and polarization angle. Existing optical microscopy measurement systems, such as inverted microscopes, have internal reflectors or beam splitters that change the polarization characteristics of light and can generally only be used for polarization-independent optical measurements. Although in some usage scenarios, the optical polarization state of the microscopy measurement system can be calibrated and corrected, the cumbersome process seriously reduces the test efficiency and will also affect the accuracy of the optical polarization information. Utility Model Content

[0003] The utility model aims to provide a polarization optical microscopy measurement system, which realizes the optical test requirements of polarization spectrum and polarization imaging of micro-nano structures by arranging various optical elements in a straight line to form a straight line optical path, thereby improving the test efficiency and the accuracy of obtaining polarization information.

[0004] In order to achieve the above-mentioned purpose, a specific embodiment of the utility model provides a polarization optical microscopic measurement system, which includes a light source, a first polarization group, a sample holder, an objective lens, an infinity correction tube lens, a two-dimensional adjustable slit, an imaging lens group and a signal collector. The light source is used to emit a light beam to form an optical path. The first polarization group is arranged in the light propagation direction of the light source, and the first polarization group includes a first linear polarizer and a first 1 / 4 wave plate that can be moved out of the optical path, and the first linear polarizer is located between the light source and the first 1 / 4 wave plate. The sample holder can move and adjust the angle and is arranged on the side of the first polarization group away from the light source. The objective lens is arranged on the side of the sample holder away from the first polarization group, and the infinity correction tube lens is arranged on the side of the objective lens away from the sample holder. The two-dimensional adjustable slit is arranged on the side of the infinity correction tube lens away from the objective lens. The imaging lens group is arranged on the side of the two-dimensional adjustable slit away from the infinity correction tube lens, and the signal collector is arranged on the side of the imaging lens group away from the two-dimensional adjustable slit.

[0005] In one or more embodiments of the present invention, the polarization optical microscopy measurement system also includes a second polarization group, which is arranged on the side of the two-dimensional adjustable slit away from the infinity correction tube lens, and the second polarization group includes a second linear polarizer and a second 1 / 4 wave plate that can be moved out of the light path, and the second 1 / 4 wave plate is located between the two-dimensional adjustable slit and the second linear polarizer.

[0006] In one or more embodiments of the present invention, the polarization optical microscopy measurement system also includes a plurality of first mirror frames, a first linear polarizer, a first quarter wave plate, a second linear polarizer and a second quarter wave plate are respectively arranged on corresponding first mirror frames, a first rotating portion is provided in the circumferential direction of the first mirror frame, the first rotating portion is passed through a pin shaft and can rotate along with the pin shaft.

[0007] In one or more embodiments of the present invention, the rotation angle of the first rotating portion is not less than 90°.

[0008] In one or more embodiments of the present invention, the light source is a broadband white light source or a monochromatic laser light source.

[0009] In one or more embodiments of the present invention, the polarization optical microscopy measurement system further includes a fiber collimator, and the light source is detachably mounted on the fiber collimator.

[0010] In one or more embodiments of the present invention, the signal collector is a CCD camera, a spectrometer, an imaging spectrometer equipped with a CCD camera, or a diode detector.

[0011] In one or more embodiments of the present invention, the imaging lens group includes two coaxially arranged first convex lenses.

[0012] In one or more embodiments of the present invention, the focal length of the first convex lens is f1, the distance between the two first convex lenses is 2f1, the distance between the two-dimensional adjustable slit and the adjacent first convex lenses is f1, and the distance between the signal collector and the adjacent first convex lenses is f1.

[0013] In one or more embodiments of the utility model, the imaging lens group also includes a second convex lens arranged between the two first convex lenses, the second convex lens is close to the first convex lens adjacent to the signal collector, the focal length of the second convex lens is f2, and the distance from the midpoint of the line connecting the centers of the two first convex lenses is f2, and the second convex lens can be moved out of the optical path.

[0014] In one or more embodiments of the present invention, the polarization optical microscopy measurement system further comprises a second frame, the second convex lens is arranged on the second frame, a second rotating part is arranged on the circumference of the second frame, and the second rotating part is passed through another pin shaft and can rotate with the pin shaft.

[0015] Another specific embodiment of the utility model also provides a polarization optical microscopic measurement system, which includes a light source, a sample holder, an objective lens, an infinity correction tube lens, a two-dimensional adjustable slit, a second polarization group, an imaging lens group and a signal collector. The light source is used to emit a light beam to form an optical path, and the sample holder can move and rotate and is arranged in the light propagation direction of the light source. The objective lens is arranged on the side of the sample holder away from the light source, and the infinity correction tube lens is arranged on the side of the objective lens away from the sample holder. The two-dimensional adjustable slit is arranged on the side of the infinity correction tube lens away from the objective lens. The second polarization group is arranged on the side of the two-dimensional adjustable slit away from the infinity correction tube lens, and the second polarization group includes a second linear polarizer and a second 1 / 4 wave plate that can be moved out of the optical path, and the second 1 / 4 wave plate is located between the two-dimensional adjustable slit and the second linear polarizer. The imaging lens group is arranged on the side of the second polarization group away from the two-dimensional adjustable slit, and the signal collector is arranged on the side of the imaging lens group away from the second polarization group.

[0016] Compared with the prior art, the various optical elements of the polarization optical microscopy measurement system of the utility model are arranged in a straight line to form a straight line optical path, which realizes the optical testing requirements of polarization spectrum and polarization imaging of micro-nano structures under the condition of polarization excitation, thereby improving the test efficiency and the accuracy of obtaining polarization information. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the implementation of the utility model or the technical solution in the prior art, the following is a brief introduction to the drawings required for the implementation or the prior art description. Obviously, the drawings described below are only some implementations recorded in the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 This is a structural diagram of a polarization optical microscopic measurement system in one embodiment of the utility model;

[0019] Figure 2 A structural diagram of a polarization optical microscopic measurement system with a polarization excitation function in one embodiment of the utility model;

[0020] Figure 3 This is a structural diagram of a polarization optical microscopic measurement system with a polarization analysis function in one embodiment of the utility model;

[0021] Figure 4 This is a structural diagram of an imaging lens group with real-space imaging function in one embodiment of the utility model;

[0022] Figure 5 This is a structural diagram of an imaging lens group with momentum space imaging function in one embodiment of the utility model;

[0023] Figure 6This is a structural diagram of the first mirror frame in one embodiment of the utility model;

[0024] Figure 7 It is a structural diagram of the second mirror frame in one embodiment of the utility model.

[0025] Explanation of main figure marks: 1. light source, 2. first polarization group, 21. first linear polarizer, 22. first quarter wave plate, 3. sample holder, 4. objective lens, 5. infinity correction tube lens, 6. two-dimensional adjustable slit, 7. second polarization group, 71. second quarter wave plate, 72. second linear polarizer, 8. imaging lens group, 81. first convex lens, 82. second convex lens, 9. signal collector, 10. first mirror frame, 11. first rotating part, 12. second mirror frame, 13. second rotating part, 14. optical fiber collimator, 15. pin shaft. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the implementation of the present invention will be clearly and completely described below in conjunction with the drawings in the implementation of the present invention. Obviously, the described implementation is only a part of the implementation of the present invention, not all of the implementations. Based on the implementation of the present invention, all other implementations obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0027] like Figures 1 to 7As shown, a polarization optical microscopic measurement system in one embodiment of the utility model comprises a light source 1, a first polarization group 2, a sample holder 3, an objective lens 4, an infinity correction tube lens 5, a two-dimensional adjustable slit 6, an imaging lens group 8 and a signal collector 9. The first polarization group 2 is arranged in the light propagation direction of the light source 1, and the first polarization group 2 comprises a first linear polarizer 21 and a first 1 / 4 wave plate 22 which can be moved out of the light path, that is, only the first linear polarizer 21 or the first 1 / 4 wave plate 22 can be moved out, or both the first linear polarizer 21 and the first 1 / 4 wave plate 22 can be moved out at the same time, and the first linear polarizer 21 is located between the light source 1 and the first 1 / 4 wave plate 22. The sample holder 3 can move and adjust the angle and is arranged on the side of the first polarization group 2 away from the light source 1. The sample holder 3 can be arranged on a three-dimensional angle adjustment mechanism to adjust the angle of the sample holder 3 on the X-axis, Y-axis and Z-axis, and then the three-dimensional angle adjustment structure is installed on the three-dimensional moving mechanism. The three-dimensional moving mechanism can drive the sample holder 3 to move on the X-axis, Y-axis and Z-axis. The movement of the three-dimensional moving mechanism on each axis can be achieved by setting a slide rail and a slider, a slider and a guide rail, etc. The objective lens 4 is arranged on the side of the sample holder 3 away from the first polarization group 2, the infinity correction tube lens 5 is arranged on the side of the objective lens 4 away from the sample holder 3, and the two-dimensional adjustable slit 6 is arranged on the side of the infinity correction tube lens 5 away from the objective lens 4. The imaging lens group 8 is composed of a plurality of convex lenses, which are arranged on the side of the two-dimensional adjustable slit 6 away from the infinity correction tube lens 5. The signal collector 9 can be a CCD camera, a spectrometer, an imaging spectrometer equipped with a CCD camera, or a diode detector. The signal collector 9 is arranged on the side of the imaging lens group 8 away from the two-dimensional adjustable slit 6.

[0028] In the above embodiment, when the sample is subjected to microscopic measurement, the sample is placed on the sample holder 3, the angle and position of the sample holder 3 are adjusted, and the sample surface to be imaged on the sample is moved to the front focal plane of the objective lens 4. The light source 1 emits a light beam, and the light beam forms polarized light after passing through the first polarization group 2. The polarized light enters the objective lens 4 after passing through the sample surface. The objective lens 4 performs the first imaging of the sample surface, magnifies the sample surface (the magnification is generally 5X, 10X, 40X, 50X or 100X), and collects the optical information of the sample surface. The infinity correction tube lens 5 is used in conjunction with the objective lens 4 so that the light beam emitted from the objective lens 4 is parallel to the optical axis. When the light beam emitted by the objective lens 4 passes through the two-dimensional adjustable slit, the two-dimensional adjustable slit selects the light signal of any tiny area (with micro-nano structure) on the sample surface, and the light signal is then injected into the imaging lens group 8, and finally the imaging signal and the spectral signal emitted by the imaging lens group 8 are collected by the signal collector 9.

[0029] It should be noted that, in the above-mentioned imaging process, the first polarization group 2 is used to excite polarized light. If linear polarized light needs to be excited by the first polarization group 2, the first 1 / 4 wave plate 22 is moved out of the light path, and the first linear polarizer 21 is used to generate linear polarized light. If circular polarized light or elliptically polarized light needs to be generated, the first linear polarizer 21 and the first 1 / 4 wave plate 22 need to be retained on the light path at the same time, the first linear polarizer 21 is used to excite linear polarized light, and then the first 1 / 4 wave plate 22 is used to convert the linear polarized light into circular polarized light or elliptically polarized light. If polarization excitation is not required, the first linear polarizer 21 and the first 1 / 4 wave plate 22 are moved out of the light path at the same time.

[0030] Based on the above imaging process, it can be seen that the various optical elements of the polarization optical microscopy measurement system in one embodiment of the utility model are arranged in a straight line to form a straight line optical path, and optical elements that affect optical polarization, such as reflectors and beam splitters, are discarded to prevent them from affecting the polarization characteristics of light. Under the condition of polarization excitation, the optical test requirements of polarization spectrum and polarization imaging of micro-nano structures are realized, thereby improving the test efficiency and the accuracy of obtaining polarization information.

[0031] In one embodiment, if Figure 1 As shown, the polarization optical microscopy measurement system also includes a second polarization group 7, which is arranged on the side of the two-dimensional adjustable slit 6 away from the infinity correction tube lens 5. The second polarization group 7 includes a second linear polarizer 72 and a second 1 / 4 wave plate 71 that can be moved out of the light path, that is, only the second linear polarizer 72 or the second 1 / 4 wave plate 71 can be moved out, or the second linear polarizer 72 and the second 1 / 4 wave plate 71 can be moved out at the same time, and the second 1 / 4 wave plate 71 is located between the two-dimensional adjustable slit 6 and the second linear polarizer 72.

[0032] After setting the second polarization group 7, the optical signal collected by the two-dimensional adjustable slit 6 can be polarized and analyzed. Polarization analysis requires the rotation of the second linear polarizer 72 and the second 1 / 4 wave plate 71. In this process, the second linear polarizer 72 is first rotated and the change in light intensity is observed to distinguish different polarization states. For example, when the second linear polarizer 72 is rotated, if the light intensity remains unchanged, the incident light may be circularly polarized light, elliptically polarized light, or natural light. In this case, the polarization state of the light can be further determined by rotating the second 1 / 4 wave plate 71. When polarization analysis is not required, the second polarization group 7 can be moved out of the light path.

[0033] In addition, since the first polarization group 2 and the second polarization group 7 can be moved out of the optical path, the polarization excitation and polarization analysis functions of the polarization optical microscopy measurement system in one embodiment of the utility model are independent of each other. When it is necessary to provide the polarization excitation and polarization analysis functions at the same time, such as Figure 1 As shown, the first polarization group 2 and the second polarization group 7 can be retained in the optical path at the same time. When only the polarization excitation function is required, such as Figure 2 As shown, only the first polarization group 2 can be retained in the optical path. When only the polarization analysis function needs to be provided, such as Figure 3 As shown, only the second polarization group 7 may be retained in the optical path.

[0034] In one embodiment, if Figure 6 As shown, the polarization optical microscopy measurement system further includes a plurality of first mirror frames 10, and the first linear polarizer 21, the first quarter wave plate 22, the second linear polarizer 72, and the second quarter wave plate 71 are respectively arranged on the corresponding first mirror frames 10. An angle mark is arranged on the first mirror frame 10, so that the operator can accurately rotate and identify the angles of the first linear polarizer 21, the first quarter wave plate 22, the second linear polarizer 72, and the second quarter wave plate 71. In addition, a first rotating portion 11 is arranged on the circumference of the first mirror frame 10, and the first rotating portion 11 is passed through a pin shaft 15 and can rotate with the pin shaft 15.

[0035] Furthermore, in order to completely move the first linear polarizer 21 , the first quarter wave plate 22 , the second linear polarizer 72 and the second quarter wave plate 71 out of the light path, the first rotating portion 11 rotates at an angle of not less than 90°, and 90° is optimal.

[0036] In one embodiment, the light source 1 is a broadband white light source or a monochromatic laser light source. The broadband white light source can be used for broadband spectrum measurement and illumination, and the monochromatic laser light source is used for monochromatic imaging measurement and fluorescence spectrum (imaging) measurement. The broadband white light source can be a stable tungsten halogen light source, and the monochromatic laser light source can be a modulated laser diode of Cobolt 06-MLD, Cobolt 08-DPL and MSL-DS-532.

[0037] Further, in order to facilitate installation and replacement of the light source 1, the light source 1 can be detachably mounted on the fiber collimator 14. In addition, the fiber collimator 14 can collimate the light beam and convert the output light into a collimated light beam in free space.

[0038] In one embodiment, if Figure 4 As shown, the imaging lens group 8 includes two first convex lenses 81 arranged coaxially to realize real space imaging. Specifically, when the two first convex lenses 81 are installed, the distance between the two first convex lenses 81 is 2f1, the distance between the two-dimensional adjustable slit 6 and the adjacent first convex lens 81 is f1, and the distance between the signal collector 9 and the adjacent first convex lens 81 is f1, and f1 is the focal length of the first convex lens 81.

[0039] In order to improve the application range of the imaging lens group 8, in one embodiment, the imaging lens group 8 also includes a second convex lens 82 disposed between the two first convex lenses 81, and the second convex lens 82 is close to the first convex lens 81 adjacent to the signal collector 9, the focal length of the second convex lens 82 is f2, and the distance from the midpoint of the center line connecting the two first convex lenses 81 is f2, and the second convex lens 82 can realize momentum space imaging after being provided. In addition, in order to facilitate the imaging lens group 8 to switch between realizing real space imaging and momentum space imaging, the second convex lens 82 can be moved out of the optical path.

[0040] In one embodiment, if Figure 7 As shown, in order to completely move the second convex lens 82 out of the light path and prevent it from changing the imaging result, the second convex lens 82 is installed on the second lens frame 12. The second lens frame 12 is provided with a second rotating portion 13 in the circumference. The second rotating portion 13 is passed through another pin shaft 15 and can rotate at least 90° following the pin shaft 15, and it is best to rotate 90°.

[0041] Another embodiment of the utility model also provides a polarization optical microscopic measurement system, which is suitable for measurement requirements that only require polarization analysis without polarization excitation. The polarization optical microscopic measurement system includes a light source 1, a sample holder 3, an objective lens 4, an infinity correction tube lens 5, a two-dimensional adjustable slit 6, a second polarization group 7, an imaging lens group 8 and a signal collector 9. The light source 1 is used to emit a light beam to form an optical path, the sample holder 3 can move and rotate and is arranged in the light propagation direction of the light source 1, the objective lens 4 is arranged on the side of the sample holder 3 away from the light source 1, the infinity correction tube lens 5 is arranged on the side of the objective lens 4 away from the sample holder 3, and the two-dimensional adjustable slit 6 is arranged on the side of the infinity correction tube lens 5 away from the objective lens 4. The second polarization group 7 is arranged on the side of the two-dimensional adjustable slit 6 away from the infinity correction tube lens 5. The second polarization group 7 includes a second linear polarizer 72 and a second 1 / 4 wave plate 71 that can be moved out of the light path, that is, only the second linear polarizer 72 or the second 1 / 4 wave plate 71 can be moved out, or the second linear polarizer 72 and the second 1 / 4 wave plate 71 can be moved out at the same time, and the second 1 / 4 wave plate 71 is located between the two-dimensional adjustable slit 6 and the second linear polarizer 72. The imaging lens group 8 is arranged on the side of the second polarization group 7 away from the two-dimensional adjustable slit 6. The signal collector 9 is arranged on the side of the imaging lens group 8 away from the second polarization group 7. In this embodiment, other structural features of the light source 1, the sample holder 3, the objective lens 4, the infinity correction tube lens 5, the two-dimensional adjustable slit 6, the second polarization group 7, the imaging lens group 8 and the signal collector 9 can be the same as the structural features in the previous embodiment, and will not be repeated here.

[0042] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim involved.

[0043] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation mode may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A polarization optical microscopy measurement system, characterized in that: include: A light source (1) for emitting a light beam to form a light path; A first polarization group (2) is arranged in the light propagation direction of the light source (1), the first polarization group (2) comprising a first linear polarization plate (21) and a first quarter wave plate (22) which can be moved out of the light path, the first linear polarization plate (21) being located between the light source (1) and the first quarter wave plate (22); A sample holder (3), which is movable and has an adjustable angle and is disposed on a side of the first polarization group (2) facing away from the light source (1); An objective lens (4) is arranged on a side of the sample holder (3) facing away from the first polarization group (2); An infinity correction tube lens (5) is arranged on a side of the objective lens (4) facing away from the sample holder (3); A two-dimensionally adjustable slit (6) is arranged on a side of the infinity correction tube lens (5) away from the objective lens (4); An imaging lens group (8) is arranged on a side of the two-dimensionally adjustable slit (6) away from the infinity correction tube lens (5); A signal collector (9) is arranged on a side of the imaging lens group (8) away from the two-dimensionally adjustable slit (6).

2. The polarization optical microscopy measurement system according to claim 1, characterized in that: The invention also comprises a second polarization group (7), wherein the second polarization group (7) is arranged on a side of the two-dimensionally adjustable slit (6) away from the infinity correction tube lens (5), and the second polarization group (7) comprises a second linear polarizer (72) which can be moved out of the optical path and a second quarter wave plate (71), and the second quarter wave plate (71) is located between the two-dimensionally adjustable slit (6) and the second linear polarizer (72).

3. The polarization optical microscopy measurement system according to claim 2, characterized in that: The invention also comprises a plurality of first mirror frames (10), wherein the first linear polarizing plate (21), the first quarter wave plate (22), the second linear polarizing plate (72) and the second quarter wave plate (71) are respectively arranged on corresponding first mirror frames (10), and a first rotating part (11) is provided on the circumference of the first mirror frame (10), and the first rotating part (11) is passed through a pin shaft and can rotate along with the pin shaft.

4. The polarization optical microscopy measurement system according to claim 3, characterized in that: The rotation angle of the first rotating part (11) is not less than 90°.

5. The polarization optical microscopy measurement system according to claim 1, characterized in that: The light source (1) is a broadband white light source or a monochromatic laser light source; and / or, The polarization optical microscopy measurement system further comprises a fiber collimator (14), and the light source (1) is detachably mounted on the fiber collimator (14); and / or, The signal collector (9) is a CCD camera, a spectrometer, an imaging spectrometer equipped with a CCD camera, or a diode detector.

6. The polarization optical microscopy measurement system according to claim 1, characterized in that: The imaging lens group (8) comprises two first convex lenses (81) arranged coaxially.

7. The polarization optical microscopy measurement system according to claim 6, characterized in that: The focal length of the first convex lens (81) is f1, the distance between the two first convex lenses (81) is 2f1, the distance between the two-dimensional adjustable slit (6) and the adjacent first convex lens (81) is f1, and the distance between the signal collector (9) and the adjacent first convex lens (81) is f1.

8. The polarization optical microscopy measurement system according to claim 6, characterized in that: The imaging lens group (8) further comprises a second convex lens (82) arranged between the two first convex lenses (81), the second convex lens (82) being close to the first convex lens (81) adjacent to the signal collector (9), the focal length of the second convex lens (82) being f2, and the distance from the midpoint of the line connecting the centers of the two first convex lenses (81) being f2, and the second convex lens (82) being able to be moved out of the optical path.

9. The polarization optical microscopy measurement system according to claim 8, characterized in that: It also comprises a second mirror frame (12), the second convex lens (82) is arranged on the second mirror frame (12), a second rotating part (13) is arranged on the circumference of the second mirror frame (12), and the second rotating part (13) is passed through another pin shaft and can rotate along with the pin shaft.

10. A polarization optical microscopy measurement system, characterized in that: include: A light source (1) for emitting a light beam to form a light path; A sample holder (3), which is movable and rotatable and is arranged in the light propagation direction of the light source (1); an objective lens (4), arranged on a side of the sample holder (3) facing away from the light source (1); An infinity correction tube lens (5) is arranged on a side of the objective lens (4) facing away from the sample holder (3); A two-dimensionally adjustable slit (6) is arranged on a side of the infinity correction tube lens (5) away from the objective lens (4); A second polarization group (7) is arranged on a side of the two-dimensionally adjustable slit (6) away from the infinity correction tube lens (5), the second polarization group (7) comprising a second linear polarizer (72) that can be moved out of the optical path and a second quarter-wave plate (71), the second quarter-wave plate (71) being located between the two-dimensionally adjustable slit (6) and the second linear polarizer (72); An imaging lens group (8) is arranged on a side of the second polarization group (7) away from the two-dimensionally adjustable slit (6); A signal collector (9) is arranged on a side of the imaging lens group (8) away from the second polarization group (7).

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