Microchip-level light beam shaping method and system
By employing a microchip-level beam shaping method, combined with a light source and metasurface devices, the problems of large size and high cost of infrared supplementary lighting equipment have been solved. This approach achieves high integration and free beam shaping, reducing system size and optimizing costs.
Patent Information
- Application Number
- CN202410623767.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-20
- Publication Date
- 2025-11-21
AI Technical Summary
Existing infrared illumination equipment is large in size, expensive, and has low integration, making it difficult to achieve efficient integration and free beam shaping.
A microchip-level beam shaping method is adopted, which combines a light source and metasurface devices, and uses simulation software to model and design the phase distribution to achieve efficient beam shaping. This includes a combination of microlens arrays, array superposition of diffraction phases and cylindrical lens phases, to generate uniform rectangular beams with small or large angles.
It improves the integration of infrared illumination equipment, reduces system size and cost, and enables free beam shaping design.
Smart Images
Figure CN120993609A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the field of beam shaping, and particularly relates to a micro-chip-level beam shaping method and system. BACKGROUND
[0002] Near-infrared imaging has a wide range of applications in modern industry, security, military and other fields. Using special infrared light sources to supplement light can expand the detection capability of existing equipment. Typical examples such as floor cleaning robots, security monitoring equipment and other equipment are equipped with active light sources. The existing infrared light supplementing equipment on the market has the problems of large size, high cost and low integration. SUMMARY
[0003] The present application provides a micro-chip-level beam shaping method and system to at least solve the above technical problems in the prior art.
[0004] The present application provides a micro-chip-level beam shaping method and system to at least solve the above technical problems in the prior art.
[0005] The method comprises: obtaining lamp hole arrangement related information of a light source, modeling the light source in simulation software, and determining the phase distribution of the light source; sequentially splicing all the obtained phases into a complete phase distribution according to the arrangement order of the lamp holes; and one-to-one corresponding the phase distribution of the light source with the phase distribution of the metasurface device, and performing full-wave simulation verification in cooperation with the light source model.
[0006] In an implementable manner, the intensity distribution of the light source is close to Gaussian light.
[0007] In an implementable manner, the phase of the metasurface device can realize multiple beam shaping functions.
[0008] In an implementable manner, the metasurface device can generate small-angle or large-angle uniform rectangular light spots.
[0009] In an implementable manner, when a small-angle uniform rectangular light spot is needed, the phase distribution is set to a microlens array form, and each lens corresponds to a lamp hole, and the phase distribution is represented as:
[0010]
[0011] wherein represents the phase distribution of the entire metasurface, i represents the lens phase corresponding to the i-th lamp hole, λ represents the central wavelength of the light source, f represents the focal length of the superlens array, and Δx represents the pitch of the vcsel lamp hole.
[0012] In an implementable manner, when a large-angle uniform rectangular light spot is needed, an array superposition diffraction phase is used, and the phase distribution is represented as:
[0013]
[0014]
[0015]
[0016] wherein represents the phase of the lens array, i represents the lens phase corresponding to the i-th aperture, λ represents the center wavelength of the light source, f represents the focal length of the superlens array, Δx represents the pitch of the vcsel aperture, represents the uniform light modulation phase at different positions on the phase plane, mod represents the modulo operation of the summed phase on 2*π.
[0017] In an embodiment, a cylindrical lens phase is superimposed on the basis of the lens array, and the phase distribution of the cylindrical lens is represented as:
[0018]
[0019] wherein represents the phase of the lens array, λ represents the center wavelength of the light source, f represents the focal length of the superlens array
[0020] Another aspect of the embodiment of the present application provides a micro-chip-level light beam shaping system, comprising a light source and a metasurface device arranged above the light source.
[0021] In an embodiment, the light source comprises a base and a light-emitting region arranged above the base, and the metasurface device comprises a substrate and nanocolumns arranged above the substrate, and the substrate is attached above the light-emitting region.
[0022] In an embodiment, a protective layer is further included, and the protective layer is arranged above the nanocolumns.
[0023] Compared with the prior art, the present application has the following advantages:
[0024] 1. The light beam shaping system of the present application can improve the integration of infrared light supplementing equipment, reduce the system size and cost;
[0025] 2. The light beam shaping system of the present application has high integration and can realize free light beam shaping effect design. BRIEF DESCRIPTION OF DRAWINGS
[0026] Figure 1 is a structural schematic diagram of a micro-chip-level light beam shaping system in the embodiment of the present application;
[0027] Figure 2 is a schematic diagram of VCSEL lamp plate arrangement in the embodiment of the present application;
[0028] Figure 3 is a phase distribution map of a metasurface in an embodiment of the present application;
[0029] Figure 4 is a phase and transmittance curve of a nanocolumn with respect to radius in an embodiment of the present application;
[0030] Figure 5 is a schematic diagram of light beam shaping effect 1 in an embodiment of the present application;
[0031] Figure 6 is a schematic diagram of light beam shaping effect 2 in an embodiment of the present application;
[0032] Legend of reference signs:
[0033] 11, base; 12, light emitting area; 13, substrate; 14, nanocolumn; 15, protective layer. DETAILED DESCRIPTION
[0034] The present application will be further described below in conjunction with the drawings.
[0035] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.
[0036] To improve the integration of infrared light supplementing equipment and reduce the system size and cost, the present application proposes a high integration superlens light beam shaping system, which can realize free light beam shaping effect design.
[0037] Reference Figure 1 The present application discloses a micro chip-level light beam shaping system, which comprises a light source, a metasurface device placed above the light source and a protective layer 15.
[0038] The intensity distribution of the light source is close to Gaussian light, and a VCSEL light source can be selected, which has a typical center wavelength of 810 nm, 850 nm or 940 nm. The light source is composed of a base 11 and a light emitting area 12, and the light emitting area 12 is placed above the base 11. One of the typical arrangement modes of the light emitting area 12 is shown in FIG. 1, in which the white color represents the array arrangement of the VCSEL. Figure 2
[0039] The super surface device is composed of a substrate 13 and nano pillars 14 arranged above the substrate. The substrate 13 is attached above the light emitting area 12, and its thickness needs to be modulated according to the phase distribution of the super surface. The nano pillars 14 are above the substrate 13. The material of the nano pillars 14 is polysilicon, and its core parameters are between 100 nm and 300 nm in diameter, between 400 nm and 1000 nm in height, and the arrangement period is set to 300 nm to 500 nm according to the actual needs of phase modulation. The overall size of the super surface device is within 4 mm, which can realize direct modulation of the VCSEL, and compared with the modulation of the EEL, the volume of the existing device can be greatly shortened. The protective layer 15 is wrapped above the nano pillars 14, which plays a protective role for the nano pillars.
[0040] The phase of the super surface device can realize various beam shaping functions, and it can generate small-angle or large-angle uniform rectangular light spots.
[0041] When a small-angle uniform rectangular light spot is needed, the phase distribution can be set in the form of a microlens array, and the phase distribution is represented as:
[0042]
[0043] wherein represents the phase distribution of the entire super surface. Each lens corresponds to a vcsel aperture, and i represents the lens phase corresponding to the ith aperture. λ represents the central wavelength of the light source, f represents the focal length of the super lens array, and Δx represents the pitch of the vcsel aperture.
[0044] When a large-angle light spot is needed, an array superposition diffraction phase can be used to generate a large-angle uniform diffraction light spot. As shown in the following formula:
[0045]
[0046]
[0047]
[0048] wherein represents the phase of the lens array, which is used to convert the divergent light emitted by the vcsel into parallel light. i represents the lens phase corresponding to the ith aperture. λ represents the central wavelength of the light source, f represents the focal length of the super lens array, and Δx represents the pitch of the vcsel aperture. represents the uniform light modulation phase at different positions on the phase plane. Mod represents the mixed phase obtained by taking the remainder of the summed phase with respect to 2*π When a specific pattern is needed, the distribution of can be adjusted to achieve it.
[0049] Line laser projection can be achieved by superimposing the phase of a cylindrical lens on a lens array. The phase of a cylindrical lens can be expressed as:
[0050]
[0051] in Let λ represent the phase of the lens array, λ represent the center wavelength of the light source, and f represent the focal length of the superlens array. Combining the phase of the cylindrical lens with the phase of the array lens achieves the desired function.
[0052] The shaping method for any of the above devices is as follows:
[0053] Obtain information about the lamp hole arrangement of the light source, model the light source in simulation software, and determine the phase distribution of the light source; stitch all the obtained phases together in the order of the lamp holes to form a complete phase distribution; make a one-to-one correspondence between the phase distribution of the light source and the phase distribution of the metasurface device, and perform full-wave simulation verification in conjunction with the light source model.
[0054] Specifically, taking VCSEL array light source and Zemax software as examples, the steps include the following:
[0055] The lighting control layout coordinates p(x,y), lamp hole size Ф=16um, divergence angle θ=25° and wavelength of 940nm were obtained for the VCSEL lamp board.
[0056] In Zemax software, model the VCSEL array light source and optimize the phase distribution required for each light source's aperture, using the following formula:
[0057]
[0058] All the obtained phases are then sequentially pieced together according to the arrangement of the lamp holes to form a pattern as shown below. Figure 3 The complete phase distribution is shown, where the black area represents the absence of nanopillar structures and the gray area represents different phase values. To ensure seamless splicing of each phase region, the phases of a single region are arranged in a regular hexagonal pattern.
[0059] Phase and transmittance scans were performed on polycrystalline silicon nanopillars with fixed height and refractive index to obtain results such as Figure 4 The transmittance and phase distribution curves are shown. The left axis represents the phase distribution, the right axis represents the transmittance distribution, and the horizontal axis represents the nanopillar radius. Nanopillars with transmittance higher than 90% are selected, while those with transmittance lower than 90% are excluded. This ensures that the phase variation of the nanopillars covers the range of 0-2π.
[0060] The obtained phase φ(x,y) was mapped one-to-one with the nanopillar, and a full-wave simulation was performed using the light source model to verify the overall beam shaping effect. Figure 5The uniform rectangular light spot is generated, and the divergence angle of the light spot is about 5°.
[0061] On this basis, more complex light spot distribution needs to be generated, and the second phase distribution needs to be designed, and the formula is as follows:
[0062]
[0063] As Figure 6 shown, a uniform linear laser needs to be generated, and the parameters in the formula are first adjusted to optimize the exit angle of each single hole to be close to 0° exit.
[0064] The Fourier iterative algorithm is used to solve the phase φ2(x, y) under the condition that the wavelength is 940 nm and the phase period is consistent with the first phase plane. The first phase and the second phase are superimposed according to the following formula:
[0065] φ(x, y) = mod[φ1(x, y) + φ2(x, y), 2 * π]
[0066] The phase and transmittance of the polycrystalline silicon nanometer column with fixed height and refractive index are scanned, and the transmittance and phase distribution curves are shown in Figure 4 The left axis of the figure is the phase distribution, the right axis is the transmittance distribution, and the horizontal axis is the nanometer column radius value. Among them, the nanometer column with a transmittance higher than 90% is selected, and the nanometer column with a transmittance lower than 90% is excluded and not used. The phase change of the nanometer column is ensured to cover 0-2π. The mixed phase nanometer column arrangement is brought into the nanometer column to do full-wave simulation, and the simulation effect is shown in Figure 6 .
[0067] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present disclosure, which should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.
Claims
1. A microchip-scale beam shaping method, characterized by, The shaping system comprises a light source and a metasurface device placed above the light source. The method comprises: Obtaining the information related to the arrangement of the lamp holes of the light source, modeling the light source in simulation software, and determining the phase distribution of the light source; Splicing all the obtained phases into a complete phase distribution in the order of the arrangement of the lamp holes; Corresponding the phase distribution of the light source with the phase distribution of the metasurface device, and performing full-wave simulation verification in cooperation with the light source model.
2. The method of claim 1, wherein: The intensity distribution of the light source is close to Gaussian light.
3. The method of claim 1, wherein: The phase of the metasurface device can realize multiple beam shaping functions.
4. The method of claim 3, wherein: The metasurface device can generate small-angle or large-angle uniform rectangular light spots.
5. The method of claim 4, wherein the microchip-level beam shaping method is characterized by, When a small-angle uniform rectangular light spot is needed, the phase distribution is set to a microlens array form, each lens corresponds to a lamp hole, and the phase distribution is represented as: wherein represents the phase distribution of the entire super surface, i represents the lens phase corresponding to the i-th lamp hole, λ represents the central wavelength of the light source, f represents the focal length of the super lens array, and Δx represents the pitch of the vcsel lamp hole.
6. The method of claim 4, wherein the microchip-level beam shaping method is characterized by, When a large-angle uniform rectangular light spot is needed, an array superposition diffraction phase is used, and the phase distribution is represented as: wherein represents the phase of the lens array, i represents the lens phase corresponding to the i-th aperture, l represents the center wavelength of the light source, f represents the focal length of the superlens array, and Ax represents the pitch of the vcsel apertures, represents the homogenization modulation phase at different positions on the phase plane, and mod represents the modulo operation of the summed phase with respect to 2*π.
7. The method of claim 6, wherein the microchip-level beam shaping method is characterized by, On the basis of the lens array, a cylindrical lens phase is superimposed, and the phase distribution of the cylindrical lens is represented as: wherein represents the phase of the lens array, λ represents the central wavelength of the light source, and f represents the focal length of the superlens array.
8. A microchip-scale optical beam shaping system, characterized by: The shaping system comprises a light source and a metasurface device placed above the light source.
9. The microchip-scale optical beam shaping system of claim 8, wherein: The light source comprises a base and a light-emitting area arranged above the base, and the metasurface device is composed of a substrate and nanometer columns arranged above the substrate, and the substrate is attached above the light-emitting area.
10. The microchip-scale optical beam shaping system of claim 9, wherein: It also comprises a protective layer arranged above the nanometer columns.