Beam shaping element and system based on metasurface
By using a metasurface device in the beam shaping element, the use of microstructure arrays to achieve the collimation and deflection of the light beam is solved, and the problem of beam shaping in traditional optical solutions requires multiple optical elements, achieving efficient beam shaping, simplifying the assembly process and reducing costs.
Patent Information
- Application Number
- CN202421074379.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2025-03-04
- Estimated Expiration
- 2034-05-17
AI Technical Summary
In the prior art, using traditional optical schemes to collimate and deflect the light beam emitted by the light source, more than two optical elements are required, resulting in large volume and weight, high cost, and complex installation and adjustment in the case of array light sources.
A metasurface-based beam shaping element is adopted, including a light source and a metasurface device. The metasurface device consists of a substrate and a metasurface. The phase distribution of the metasurface consists of a collimated phase and a deflected phase, and the collimation and deflection of the light beam is achieved through a microstructure array.
The collimation and deflection of the light beam is achieved on the single layer metasurface, reducing the number of optical components, reducing volume and weight, simplifying the assembly process, and reducing costs.
Smart Images
Figure CN222561860U_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of beam shaping, and in particular relates to a beam shaping element and system based on a metasurface. Background Art
[0002] In the fields of 3D printing, AR display, etc., it is necessary to collimate and shape the output light of the light source. The design method based on geometric optics is to use a lens group to collimate the light source, and then use reflectors, prisms and other devices to deflect the direction of light propagation.
[0003] Using traditional optical solutions to collimate and deflect the light beam emitted by a light source requires more than two optical elements, which are large in size and weight, high in cost, and complex in assembly and adjustment in the case of an array light source. Utility Model Content
[0004] The present application provides a beam shaping element and system based on a metasurface to at least solve the above technical problems existing in the prior art.
[0005] On the one hand, an embodiment of the present application provides a beam shaping element based on a metasurface, including a light source and a metasurface device, wherein the metasurface device is located downstream of the light source; the metasurface device includes a substrate and a metasurface arranged on the substrate, and the phase distribution of the metasurface includes a collimated phase and a deflected phase.
[0006] In one possible implementation manner, the phase distribution of the metasurface is expressed by the following formula:
[0007]
[0008] in, is the collimation phase, is the deflection phase.
[0009] In one possible implementation manner, the collimation phase is calculated and optimized based on the divergence angle and aperture size of the light source.
[0010] In one possible implementation, a form of the collimation phase is expressed as follows:
[0011]
[0012] Where λ is the wavelength of the light source, x and y are the position coordinates on the metasurface, and f is the focal length.
[0013] In one possible implementation manner, the deflection phase is calculated from a final required chief light ray deflection angle.
[0014] In one possible implementation, a form of the deflection phase is expressed as follows:
[0015]
[0016] Here, θ is the deflection angle.
[0017] In one possible implementation manner, the metasurface is composed of a microstructure array, and the phase distribution of the metasurface can be changed by the type, size and arrangement of the microstructures, and the phase change range is within 0-2π.
[0018] In one embodiment, the microstructure is in the shape of a nanorod or a nanohole.
[0019] In one possible implementation, the light source is a VCSEL array light source or an LED array light source.
[0020] Another aspect of an embodiment of the present application provides a beam shaping system, comprising any one of the above-mentioned beam shaping elements. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic diagram of the VCSEL array shaping principle in Example 1 of the present application;
[0022] Figure 2 This is a schematic diagram of the VCSEL array shaping principle in Example 1 of the present application;
[0023] Figure 3 is a schematic diagram of the structure of the metasurface device in the embodiment of the present application;
[0024] Figure 4 It is a schematic diagram of the structure of the super surface unit in the embodiment of the present application.
[0025] Figure 5 is a schematic diagram of phase and transmittance obtained by scanning microstructure parameters in an embodiment of the present application;
[0026] Figure 6 This is a schematic diagram of VCSEL array shaping ray tracing in Example 1 of the present application;
[0027] Figure 7 This is a schematic diagram of the VCSEL array-shaped light spot in Example 1 of the present application;
[0028] Figure 8 This is a schematic diagram of the LED array light source shaping principle in Example 2 of the present application;
[0029] Fig. 9 is a schematic diagram of LED array ray tracing in Example 2 of the present application;
[0030] Fig.10 This is a schematic diagram of the LED array light spot in Example 2 of the present application; DETAILED DESCRIPTION
[0031] The present application is further described in detail below in conjunction with the accompanying drawings.
[0032] In the description of the present application, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0033] This application discloses a beam shaping element based on a metasurface, which can realize the collimation and deflection of a light beam in a single layer, and finally realize the shaping of the light beam of a light source. The volume of the beam shaping element based on the metasurface is greatly reduced compared with the traditional optical solution, and the monolithic structure is simple, which reduces the difficulty of assembly.
[0034] One purpose of the present application is to provide a device for shaping a metalens into a specific shape, which can collimate and deflect light from a light source without the need for additional beam deflection elements such as prisms.
[0035] Specifically, the beam shaping element includes a light source and a metasurface device, and the metasurface device is located downstream of the light source. The metasurface device includes a substrate and a metasurface placed on the substrate. The light source can be a VCSEL array light source or an LED array light source.
[0036] The metasurface is composed of an array of microstructures, and the phase distribution of the metasurface can be changed by the type, size and arrangement of the microstructures, with the phase change range being 0-2π. The material of the substrate is a material that is transparent to near-infrared wavelengths. The shape of the microstructure of the metasurface can be a nanocolumn or a nanohole, and the material is a material that is transparent to near-infrared wavelengths and has a high refractive index.
[0037] The phase distribution of the metasurface is a superposition of two parts: the collimation phase and the deflection phase. The collimation phase can be calculated and optimized based on the divergence angle and aperture size of the light source, while the deflection phase is calculated based on the final required main light deflection angle.
[0038] Example 1
[0039] Beam shaping based on VCSEL arrays:
[0040] This embodiment provides a shaping method for a VCSEL array light source, wherein the VCSEL array is collimated and deflected by a superlens, so that two rows of VCSEL arrays arranged at intervals are shaped into a non-displaced light spot at a position of 3 mm.
[0041] like Figure 1As shown, after the light emitted by the VCSEL array light source 1 is modulated and shaped by the metasurface 2, the generated light spots 3 are seamlessly spliced into a row.
[0042] Another shaping method is Figure 2 As shown, a row of VCSEL array light sources 1 are arranged at intervals in the same direction. After being collimated and deflected by the metasurface 2, the light spots 3 will form a seamless row.
[0043] refer to Figure 3 , the phase design process of the metasurface is as follows:
[0044] 1. Calculate the phase distribution required by the metasurface. The phase distribution of the metasurface can be expressed by the following formula:
[0045]
[0046] in is the collimation phase, is the deflection phase.
[0047] Collimation Phase It can be optimized by ray tracing, one form of which can be expressed as:
[0048]
[0049] Where λ is the wavelength of the light source, x and y are the position coordinates on the metasurface, and f is the focal length.
[0050] Deflection Phase The deflection angle can be calculated through geometric relationships, one of which can be expressed as:
[0051]
[0052] Where θ is the deflection angle.
[0053] 2. Select appropriate metasurface unit structures and arrange them in a specific way to form a metasurface. Figure 4 As shown in Figure 2, by changing the radius of the microstructure, different phase values can be obtained, some of which are shown in Figure 2. Figure 5 By matching the phase value with the desired metasurface phase distribution, the phase arrangement of the metasurface can be obtained.
[0054] 3. Figure 6 The effect of assembling each VCSEL array with the metasurface is shown. The light spot at 3mm is as follows Figure 7 As shown, it can be seen that the light spot has no up-down misalignment and no gap in the middle.
[0055] Example 2
[0056] Beam shaping for LED arrays:
[0057] This embodiment provides a shaping method for an LED array light source, such as Figure 8 As shown, after being collimated and deflected by the metasurface 5, the LED light sources 4 converge to the same position at 3 mm, forming a light spot 6 with higher brightness.
[0058] Fig. 9 is a schematic diagram of the light path, and the light spot effect is as follows Fig.10 shown.
[0059] The present application also discloses a beam shaping system, which comprises any one of the above-mentioned beam shaping elements.
[0060] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.
Claims
1. A beam shaping element based on a metasurface, characterized in that: comprising a light source and a metasurface device, wherein the metasurface device is located downstream of the light source; The metasurface device comprises a substrate and a metasurface arranged on the substrate, and the phase distribution of the metasurface comprises a collimated phase and a deflected phase.
2. A beam shaping element according to claim 1, characterized in that: The phase distribution of the metasurface is expressed by the following formula: in, is the collimation phase, is the deflection phase.
3. A beam shaping element according to claim 1, characterized in that: The collimation phase is calculated and optimized according to the divergence angle and aperture size of the light source.
4. A beam shaping element according to claim 3, characterized in that: One form of the collimation phase is expressed as follows: Where λ is the wavelength of the light source, x and y are the position coordinates on the metasurface, and f is the focal length.
5. The beam shaping element according to claim 1, characterized in that: The deflection phase is calculated based on the final required main light ray deflection angle.
6. A beam shaping element according to claim 5, characterized in that: One form of the deflection phase is expressed as follows: Here, θ is the deflection angle.
7. The beam shaping element according to claim 1, characterized in that: The metasurface is composed of a microstructure array, and the phase distribution of the metasurface can be changed by the type, size and arrangement of the microstructures, and the phase change range is within 0-2π.
8. The beam shaping element according to claim 7, characterized in that: The microstructure is in the shape of nanorods or nanoholes.
9. The beam shaping element according to claim 1, characterized in that: The light source is a VCSEL array light source or an LED array light source.
10. Beam shaping system, characterized in that: The invention comprises a beam shaping element according to any one of claims 1 to 9.