Surface microstructure and light absorbing device for suppressing stray light

Abstract

The present disclosure provides a surface microstructure and a light absorbing device for suppressing stray light, which belongs to the field of stray light suppression of optical systems, and includes a substrate and a plurality of reflective structures arranged on the surface of the substrate, wherein the plurality of reflective structures are periodically arranged on the surface of the substrate to form a sawtooth structure, wherein the reflective structure includes a front reflective surface and a rear reflective surface, wherein the front reflective surface and the rear reflective surface are arranged obliquely, and the front reflective surface, the rear reflective surface and the substrate surface form a triangular structure, and the surface microstructure is arranged on the inner wall of the light absorbing device. By arranging the surface microstructure on the inner wall of the light absorbing device to replace the bulky light shielding cover structure, the overall volume and mass of the optical system are further reduced.

Description

Technical Field

[0001] The present invention belongs to the field of stray light suppression in optical systems, and in particular relates to a surface microstructure and a light absorbing device for suppressing stray light. Background Art

[0002] Stray light is the radiation energy of other non-imaging light that diffuses onto the detector surface in addition to the imaging light in the optical system, as well as the radiation energy of imaging light that reaches the detector through abnormal optical paths. Stray light will seriously affect the imaging quality of the optical system. Usually, it is suppressed by adding an additional light shield, but the light shield has a large volume and heavy mass, which increases the overall volume and mass of the optical system and cannot meet the design requirements of miniaturization and lightweight. Summary of the invention

[0003] In view of the defects or shortcomings in the prior art, the present disclosure provides a surface microstructure and a light absorbing device for suppressing stray light, which can replace the bulky sunshade and further reduce the overall volume and weight of the optical system.

[0004] In order to achieve the above objectives, the present disclosure adopts the following technical solutions:

[0005] At least one embodiment of the present disclosure provides a surface microstructure for suppressing stray light, including a substrate and a plurality of reflective structures disposed on the surface of the substrate, wherein the plurality of reflective structures are periodically arranged on the surface of the substrate to form a sawtooth structure.

[0006] Furthermore, the reflective structure comprises a front reflective surface and a rear reflective surface, the front reflective surface and the rear reflective surface are arranged obliquely, and the front reflective surface, the rear reflective surface and the substrate surface form a triangular structure.

[0007] Furthermore, the angle between the front reflective surface and the rear reflective surface is 90°.

[0008] Furthermore, the front reflective surface faces the incident direction of light.

[0009] Furthermore, the plurality of reflective structures are periodically arranged on the substrate surface, wherein the period d is

[0010]

[0011] Where λ is the central wavelength of the stray light, m ​​is an integer, and α is the angle of the external stray light that affects the optical quality relative to the optical axis of the optical system.

[0012] Furthermore, the angle between the front reflection surface and the base line of the substrate surface is equal to 45°.

[0013] Furthermore, the angle between the front reflection surface and the substrate surface limit is less than 45°.

[0014] Furthermore, the substrate surface is a plane or a curved surface.

[0015] At least one embodiment of the present disclosure further provides a light absorbing device, comprising a surface microstructure for suppressing stray light as described in any one of the above items.

[0016] Furthermore, the surface microstructure is arranged on the inner wall of the light absorbing device.

[0017] One or more specific embodiments of the present disclosure achieve at least the following technical effects:

[0018] 1. By setting two reflective surfaces at a certain angle, the stray light incident from a certain direction can be directly reflected out or reflected and absorbed multiple times, thereby achieving the effect of suppressing external stray light.

[0019] 2. By arranging the surface microstructure on the inner wall of the light absorbing device to replace the bulky light shielding structure, the overall volume and mass of the optical system can be further reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the surface microstructure in Example 1 of the present disclosure;

[0021] Figure 2 Schematic diagram of the surface microstructure in Example 2 of the present disclosure;

[0022] Figure 3 This is a schematic diagram of the structure of the light absorption device in Example 3 of the present disclosure;

[0023] Figure 4 is a schematic diagram of another surface microstructure in Example 2 of the present disclosure;

[0024] Figure 5 This is a schematic diagram of the first optical path of the surface microstructure in Example 1 of the present disclosure;

[0025] Figure 6 This is a schematic diagram of the second optical path of the surface microstructure in Example 1 of the present disclosure;

[0026] Figure 7 This is a schematic diagram of the first optical path of the surface microstructure in Example 2 of the present disclosure;

[0027] Figure 8 This is a schematic diagram of the second optical path of the surface microstructure in Example 2 of the present disclosure;

[0028] Fig. 9 This is another schematic diagram of the optical path of the surface microstructure in Embodiment 2 of the present disclosure;

[0029] Among them: 1. Base; 2. Front reflective surface; 3. Back reflective surface; 4. Surface baseline; 5. Light absorbing device. DETAILED DESCRIPTION

[0030] The present disclosure is further described below in conjunction with the accompanying drawings and embodiments.

[0031] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present disclosure. Unless otherwise specified, all technical and scientific terms used in the present disclosure have the same meanings as those commonly understood by those skilled in the art to which the present disclosure belongs.

[0032] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless otherwise explicitly stated in the present disclosure, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or their combinations;

[0033] For the convenience of description, if the words "up", "down", "left" and "right" appear in the present disclosure, they only indicate that they are consistent with the up, down, left and right directions of the drawings themselves, and do not limit the structure. They are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present disclosure.

[0034] Terminology explanation section: The terms "install", "connect", "connect", "fixed" and the like in the present disclosure should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements, or an interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances.

[0035] Example 1

[0036] A typical implementation of the present disclosure is as follows: Figure 1 As shown, a surface microstructure for suppressing stray light includes a substrate 1 and a plurality of reflective structures arranged on the surface of the substrate. The plurality of reflective structures are periodically arranged on the surface of the substrate 1 to form a sawtooth structure.

[0037] The multiple reflective structures are periodically arranged on the surface of the substrate 1, wherein the period d is

[0038]

[0039] Where λ is the central wavelength of the stray light, m ​​is an integer, and α is the angle of the external stray light that affects the optical quality relative to the optical axis of the optical system.

[0040] The reflective structure includes a front reflective surface 2 and a rear reflective surface 3, wherein the front reflective surface 2 faces the incident direction of light, and the front reflective surface 2 and the rear reflective surface 3 are arranged obliquely, and the front reflective surface 2, the rear reflective surface 3 and the surface of the substrate 1 form a triangular structure, and the angle β between the front reflective surface 2 and the rear reflective surface 3 is 90°.

[0041] The substrate 1 can be a plane or a curved surface. When the substrate 1 is a plane, the reflective structure is arranged on two mutually parallel substrates 1, and the reflective structures on the two substrates 1 are arranged symmetrically. When the substrate 1 is a curved surface, the substrate 1 is a cylindrical structure, and the reflective structure is arranged along the axis direction of the cylinder.

[0042] The stray light is reflected between two mutually symmetrical surface microstructures, or reflected back to the incident direction, or after multiple reflections and absorption, the effect of suppressing the stray light is achieved.

[0043] The angle θ between the front reflection surface 2 and the base line 4 of the substrate 1 surface is equal to 45°.

[0044] The angle β between the current reflective surface and the back reflective surface is 90°, and the angle θ between the front reflective surface and the base line of the substrate surface is 45°, such as Figure 1 As shown; at this time, when the angle between the stray light and the optical axis is greater than or equal to the angle between the back reflection surface and the baseline of the substrate surface, as shown Figure 5 As shown in the figure, the stray light will be reflected back at the same angle and will not enter the optical system. When the angle between the stray light and the optical axis is smaller than the angle between the back reflection surface and the baseline of the substrate surface, such as Figure 6 As shown, the stray light will enter the optical system again at the same angle after being reflected, and will be attenuated and suppressed after multiple reflections.

[0045] Example 2

[0046] Another embodiment of the present disclosure is as follows: Figure 2 As shown, a surface microstructure for suppressing stray light is different from Example 1 in that the angle θ between the front reflection surface and the baseline of the substrate surface is less than 45°.

[0047] The angle β between the current reflecting surface and the back reflecting surface is 90°, and the angle θ between the front reflecting surface and the base line of the substrate surface is less than 45°. Figure 2 As shown, at this time, when the angle between the stray light and the optical axis is greater than or equal to the angle between the back reflection surface and the baseline of the substrate surface, as shown in Figure 7As shown in the figure, the stray light will be reflected back at the same angle and will not enter the optical system. When the angle between the stray light and the optical axis is smaller than the angle between the back reflection surface and the baseline of the substrate surface, such as Figure 8 As shown, after being reflected, the stray light will enter the optical system again at the same angle and will be attenuated and suppressed after multiple reflections.

[0048] The angle β between the current reflection surface and the back reflection surface is 90°, and the angle θ between the front reflection surface and the base line of the substrate surface is greater than 45°. Figure 4 As shown; at this time, when the angle between the stray light and the optical axis is greater than or equal to the angle between the back reflection surface and the baseline of the substrate surface, part of the stray light will be reflected a small amount and converted into a small angle to enter the optical system, such as Fig. 9 As shown, strong stray light cannot be suppressed well.

[0049] Example 3

[0050] The present disclosure provides a light absorbing device, such as Figure 3 As shown, it includes a surface microstructure for suppressing stray light as described in Example 1 or Example 2.

[0051] The surface microstructure is arranged on the inner wall of the light absorbing device, and has the advantages of small size and light weight. It can replace the bulky light shield and will not reduce the effect of suppressing stray light, further reducing the overall volume and weight of the optical system.

[0052] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A surface microstructure for suppressing stray light, characterized in that: It includes a substrate and a plurality of reflective structures arranged on the surface of the substrate, wherein the plurality of reflective structures are periodically arranged on the surface of the substrate to form a sawtooth structure; The reflective structure comprises a front reflective surface and a rear reflective surface, the angle between the front reflective surface and the rear reflective surface is 90°, the angle θ between the front reflective surface and the baseline of the substrate surface is less than or equal to 45°, when the angle between the stray light and the optical axis is greater than or equal to the angle between the rear reflective surface and the baseline of the substrate surface, the stray light is reflected back at the same angle and will not enter the optical system; when the angle between the stray light and the optical axis is less than the angle between the rear reflective surface and the baseline of the substrate surface, the stray light enters the optical system again at the same angle after reflection, and is attenuated and suppressed after multiple reflections; The front reflective surface faces the incident direction of light; The multiple reflective structures are periodically arranged on the substrate surface, with a period of d.

2. A surface microstructure for suppressing stray light according to claim 1, characterized in that: The front reflecting surface and the rear reflecting surface are arranged obliquely, and the front reflecting surface, the rear reflecting surface and the substrate surface form a triangular structure.

3. The surface microstructure for suppressing stray light according to claim 1, characterized in that: Where λ is the central wavelength of the stray light, m ​​is an integer, and α is the angle of the external stray light that affects the optical quality relative to the optical axis of the optical system.

4. A surface microstructure for suppressing stray light according to claim 2, characterized in that: The angle between the front reflection surface and the base line of the substrate surface is equal to 45°.

5. The surface microstructure for suppressing stray light according to claim 2, characterized in that: The angle between the front reflection surface and the substrate surface limit is less than 45°.

6. The surface microstructure for suppressing stray light according to claim 1, characterized in that: The substrate surface is a flat surface or a curved surface.

7. A light absorbing device, characterized in that: A surface microstructure for suppressing stray light comprising the surface microstructure as described in any one of claims 1 to 6.

8. The light absorbing device according to claim 7, characterized in that: The surface microstructure is arranged on the inner wall of the light absorbing device.

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