Collimating superlens and design method, collimating system based on collimating superlens
By designing a collimating superlens with a specific phase distribution and arranging amorphous silicon cylinders, the problem of the curvature radius accuracy limitation of optical convex lenses was solved, achieving higher laser beam collimation performance and less crosstalk, thus improving the collimation effect of laser measurement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI LIGHT-WONDER OPTICS CO LTD
- Filing Date
- 2023-07-18
- Publication Date
- 2026-04-17
AI Technical Summary
Existing optical convex lens manufacturing processes limit the accuracy of the radius of curvature, resulting in limited collimation performance and affecting the collimation effect of laser measurements. In particular, crosstalk is easily generated when measuring micromirror arrays using VCSEL arrays.
A collimating superlens design method with a specific phase distribution is adopted. The arrangement of amorphous silicon cylinders replaces the curved surface distribution of traditional optical convex lenses. Combined with high-precision micro-nano fabrication technology, the radius and position phase of the amorphous silicon cylinders are optimized to improve collimation performance.
It breaks through the limitations of traditional curvature radius processing, improves the collimation performance of laser beams, reduces crosstalk, and enhances the collimation effect of laser measurement.
Smart Images
Figure CN116859491B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of laser measurement technology, specifically to collimating superlenses and their design methods, and collimation systems based on collimating superlenses. Background Technology
[0002] In the field of laser measurement, it is necessary to collimate the laser beam, and the collimation effect directly affects the measurement accuracy. For example, when using a VCSEL array to measure the deflection angle of each mirror in a micromirror array (MMA), if the divergence angle of the emitted light spot from the VCSEL array is large, it will illuminate the adjacent mirrors of the mirror under test, thus generating crosstalk and affecting the measurement result of the deflection angle.
[0003] Optical convex lenses have a collimating effect. Ideally, for a point light source located at the focal point of an optical convex lens, the emitted light beam is converted into parallel light after passing through the lens. In practice, the collimating effect of an optical convex lens is related to its radius of curvature. Current manufacturing processes for optical convex lenses limit the accuracy of the radius of curvature in their fabrication, thus limiting their collimating performance.
[0004] Existing VCSEL beam collimation schemes are prone to crosstalk, which affects the measurement results of the deflection angle. Furthermore, the collimation performance of optical convex lenses is limited by the machining accuracy of the radius of curvature, and with the current level of technology, certain optical convex lenses with specific radii of curvature cannot be manufactured. Summary of the Invention
[0005] To address the shortcomings of existing beam collimation technologies, this application provides a collimating superlens and its design method, as well as a VCSEL array collimation system based on the collimating superlens. By employing a collimating superlens design method with a specific phase distribution, the limitations of traditional curvature radius processing are overcome. The arrangement of amorphous silicon cylinders with specific radius dimensions replaces the curved surface distribution of traditional optical convex lenses. Based on high-precision micro-nano fabrication technology, the collimation performance is improved.
[0006] The technical solution provided by this invention is as follows:
[0007] This invention provides a collimation system for a VCSEL array based on a collimating superlens, comprising: a VCSEL array and a collimating superlens array;
[0008] The VCSEL array comprises several VCSEL units;
[0009] The collimating superlens array includes several collimating superlenses, and each of the collimating superlenses is arranged in a one-to-one correspondence with a number of VCSEL units to collimate the emitted beam of the VCSEL unit.
[0010] The collimating superlens is composed of amorphous silicon cylinders of different radii, wherein the radius of each amorphous silicon cylinder is determined according to the position and phase of each position of the collimating superlens, so that the amorphous silicon cylinders of different radii are arranged according to the position and phase distribution of the collimating superlens.
[0011] More preferably, the position phase of each position of the collimating superlens is optimized based on minimizing the divergence angle of the emitted light spot at that position.
[0012] More preferably, the radius of the amorphous silicon cylinder at each position is determined from the target phase and target transmittance of the transmitted light from the amorphous silicon cylinder at different radii, based on the position phase of each position of the collimating superlens, wherein the target phase is continuous and its range is greater than or equal to 2π, and the target transmittance is greater than or equal to 0.8.
[0013] More preferably, the collimating superlens is disposed within the VCSEL unit.
[0014] More preferably, it also includes a substrate and a beam isolation element;
[0015] The collimating superlens is disposed on one side of the substrate, and the VCSEL unit is located on the other side of the substrate;
[0016] The beam isolation element is disposed on the other side of the substrate in conjunction with the adjacent VCSEL unit to isolate the beam emitted by the adjacent VCSEL unit.
[0017] More preferably, it also includes a light-shielding film, which, in conjunction with the collimating superlens, is disposed on the empty area of the substrate other than the collimating superlens area, so as to block the emitted light beam from the empty area of the substrate other than the collimating superlens area, so that the emitted light beam only passes through the collimating superlens area.
[0018] This invention also provides a method for designing a collimating superlens, wherein the collimating superlens is composed of amorphous silicon cylinders of different radii, and the method for designing the collimating superlens includes the following steps:
[0019] The position and phase of each position of the collimating superlens are optimized to obtain the position and phase of each position of the collimating superlens.
[0020] The phase and transmittance of transmitted light from amorphous silicon cylinders with different radii were simulated to obtain the target phase and target transmittance.
[0021] Based on the position and phase of each position of the collimating superlens, the radius of the amorphous silicon cylinder at each position of the collimating superlens is determined from the target phase and the target transmittance, so as to obtain the structural arrangement of amorphous silicon cylinders with different radii.
[0022] More preferably, the position phase of the collimating superlens at each position is optimized using a phase distribution function to obtain the position phase of the collimating superlens at each position. The phase distribution function is:
[0023]
[0024] Where (x,y) represents the position coordinates on the collimating superlens. R0 represents the position and phase on the collimating superlens, and a represents the radius of the collimating superlens. i The coefficients are for optimization, and n is the parameter to be selected for optimization.
[0025] More preferably, the step of simulating the phase and transmittance of transmitted light from amorphous silicon cylinders at different radii to obtain the target phase and target transmittance specifically includes:
[0026] Simulate the phase and transmittance of transmitted light from an amorphous silicon cylinder at different radii within a preset radius range;
[0027] The simulated phase and transmittance are filtered according to preset filtering conditions to obtain target phase and target transmittance. The preset filtering conditions are: the target phase is continuous and its range is greater than or equal to 2π, and the target transmittance is greater than or equal to 0.8.
[0028] The present invention also provides a collimating superlens, which is composed of amorphous silicon cylinders of different radii, and the structural arrangement of the amorphous silicon cylinders of different radii is designed using the above-mentioned collimating superlens design method.
[0029] The collimating superlens and design method according to the above embodiments, and the VCSEL array collimating system based on the collimating superlens, break through the limitations of traditional curvature radius processing by using a collimating superlens design method with specific phase distribution to design the collimating superlens. The collimating performance is improved by replacing the curved surface distribution of traditional optical convex lenses with the arrangement of amorphous silicon cylinders of specific size. Attached Figure Description
[0030] Figure 1 This is a schematic diagram of a VCSEL array collimation system.
[0031] Figure 2 This is a schematic diagram illustrating the principle of a collimating superlens.
[0032] Figure 3 for Figure 2 Another view;
[0033] Figure 4 A schematic diagram of the optimized position and phase distribution;
[0034] Figure 5 This is a schematic diagram of the target phase and target transmittance distribution. Detailed Implementation
[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.
[0036] VCSEL: Vertical Cavity Surface Emitting Laser.
[0037] This invention provides a collimation system based on a collimating superlens VCSEL array, comprising: a VCSEL array 100 and a collimating superlens array 200;
[0038] The VCSEL array 100 includes several VCSEL units 101;
[0039] The collimating superlens array 200 includes several collimating superlenses 201, which are arranged one-to-one with several VCSEL units 101 to collimate the emitted beam of the VCSEL unit 101.
[0040] The collimating superlens 201 is composed of amorphous silicon cylinders of different radii. The radius of each amorphous silicon cylinder is determined according to the position and phase of each position of the collimating superlens 201, so that the amorphous silicon cylinders of different radii are arranged according to the position and phase distribution of the collimating superlens 201.
[0041] This invention innovatively employs a specific phase distribution design for the collimating superlens structure, breaking through the limitations of traditional curvature radius processing. It replaces the curved surface distribution of traditional optical convex lenses with the arrangement of amorphous silicon cylinders of specific dimensions, thereby improving collimation performance.
[0042] The specific phase distribution is an optimized design of the position phase of each position of the collimating superlens 201 based on minimizing the divergence angle of the outgoing light spot at that position, so as to obtain a specific phase at each position of the collimating superlens 201.
[0043] Based on the specific positional phases of the collimating superlens 201 at each location, the radius of the amorphous silicon cylinder at that location is determined from the target phase and target transmittance of the transmitted light from the amorphous silicon cylinder under different radii. The standard for the target phase is that it is continuous and its range is greater than or equal to 2π, and the standard for the target transmittance is that it is greater than or equal to 0.8. By setting standards for the target phase and target transmittance, the amorphous silicon cylinder radius determined under these standards can achieve a better collimation effect.
[0044] For the specific optimization design process of the position and phase of each position of the collimating superlens 201, please refer to the collimating superlens design method below. The method of obtaining the target phase and target transmittance should also refer to the collimating superlens design method below, and will not be repeated here.
[0045] Since the radius of each amorphous silicon cylinder in the collimating superlens 201 is selected based on the position and phase of the corresponding position in the collimating superlens 201, and the position and phase are obtained through optimization, the radius of the amorphous silicon cylinder is optimized along with the position and phase before it is determined. This indirectly achieves the optimized selection of the radius of the amorphous silicon cylinder. That is, once the radius of the amorphous silicon cylinder is determined, its determined radius value is the optimal value. Thus, the structural distribution of the collimating superlens 201 reaches the optimal distribution, thereby improving the collimating performance of the collimating superlens 201.
[0046] To achieve beam collimation, the collimating superlens 201 and the VCSEL unit 101 are matched. This application provides two matching schemes. In practical applications, one of the schemes can be selected for implementation, or the schemes provided in this application can be modified to achieve the same collimation effect.
[0047] The first approach is to place the collimating superlens 201 inside the VCSEL unit 101. That is, to adopt a bottom-emitting VCSEL structure, the VCSEL unit 101 emits light from the back side, and the collimating superlens 201 is directly etched on the substrate on the back side of the VCSEL unit 101 to achieve collimation of the emitted beam.
[0048] The second option is to separate the collimating superlens 201 from the VCSEL unit 101, such as... Figure 1 As shown, in this structure, the VCSEL array collimation system provided in this application also includes a substrate 300 and a beam isolation element 400;
[0049] The collimating superlens 201 is disposed on one side of the substrate 300, and the VCSEL unit 101 is located on the other side of the substrate 300. The substrate 300 can be a glass substrate; the structural diagram of the collimating superlens 201 disposed on the substrate 300 is shown below. Figure 2 and Figure 3 As shown.
[0050] The beam isolation element 400 is disposed on the other side of the substrate 300 in conjunction with the adjacent VCSEL unit 101 to isolate the beam emitted by the adjacent VCSEL unit 101. For example, the beam isolation element 400 can be a honeycomb panel.
[0051] Furthermore, the above structure also includes a light-shielding film 500. The light-shielding film 500, in conjunction with the collimating superlens 201, is disposed on the empty area of the substrate 300 other than the area of the collimating superlens 201, to block the emitted light beam from the empty area of the substrate 300 other than the area of the collimating superlens 201, so that the emitted light beam only passes through the area of the collimating superlens 201. For example, the light-shielding film 500 can be an opaque chromium film (Cr layer).
[0052] This application also provides a collimating superlens design method. This method performs a specific phase distribution design on the collimating superlens used in the VCSEL array collimation system provided above. The specific structural distribution of the collimating superlens is achieved by designing an amorphous silicon cylinder with a specific radius. The collimating superlens design method specifically includes the following steps:
[0053] S100: Optimize the position and phase of each position of the collimating superlens to obtain the position and phase of each position of the collimating superlens.
[0054] S200: Simulates the phase and transmittance of transmitted light from amorphous silicon cylinders at different radii to obtain the target phase and target transmittance.
[0055] S300: Based on the position and phase of each position of the collimating superlens, determine the radius of the amorphous silicon cylinder at each position of the collimating superlens in terms of the target phase and the target transmittance, so as to obtain the structural arrangement of amorphous silicon cylinders with different radii.
[0056] In step S100, the position and phase of each position of the collimating superlens are optimized. Specifically, the position and phase of each position of the collimating superlens are optimized using a phase distribution function to obtain the position and phase of each position of the collimating superlens. The optimized position and phase distribution is as follows: Figure 4 As shown, the phase distribution function is as follows:
[0057]
[0058] Where (x,y) represents the position coordinates on the collimating superlens. R0 represents the position and phase on the collimating superlens, and a represents the radius of the collimating superlens. i The optimization coefficient is n, which is a parameter selected based on the actual target optimization result. For example, n can be selected as 8 or 4. In this application, n is selected as 4.
[0059] For a traditional collimating lens, its phase distribution satisfies the formula:
[0060]
[0061] Where λ is the incident light wavelength, and f is the lens focal length, i.e., the distance between the collimating superlens and the VCSEL unit. Once the collimation system structure is determined, and the distance between the collimating superlens and the VCSEL unit is determined, the phase is also determined, and the phase cannot be changed or optimized.
[0062] Even if the collimation system structure is determined, the phase distribution function used in this application can be optimized by adjusting the coefficient α. i The phase can be further modified and optimized until the optimal phase is obtained, and finally, the optimal collimating superlens structure distribution is obtained.
[0063] In step S200, the phase and transmittance of transmitted light from an amorphous silicon cylinder at different radii are simulated to obtain the target phase and target transmittance. This specifically includes the following steps:
[0064] S201: Simulates the phase and transmittance of transmitted light from an amorphous silicon cylinder at different radii within a preset radius range.
[0065] For example, the phase and transmittance φ(r) and t(r) of transmitted light from amorphous silicon cylinders with different radii can be simulated using optical simulation software (FDTD, COMSOL, etc.).
[0066] S202: The simulated phase and transmittance are filtered according to preset screening conditions to obtain the target phase and target transmittance. These preset screening conditions are: the target phase is continuous and its range is greater than or equal to 2π, and the target transmittance is greater than or equal to 0.8. The distribution of the obtained target phase and target transmittance is as follows: Figure 5 As shown.
[0067] Furthermore, this application also provides a collimating superlens, which is composed of an arrangement of amorphous silicon cylinders of different radii. The structural arrangement of the amorphous silicon cylinders of different radii is designed using the aforementioned collimating superlens design method. Because this collimating superlens uses a specific phase distribution design to overcome the limitations of traditional curvature radius processing, and replaces the curved surface distribution of traditional optical lenses with an arrangement of amorphous silicon cylinders of specific radius dimensions, the collimation performance is improved.
[0068] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.
Claims
1. A collimation system for a VCSEL array based on a collimating superlens, characterized in that, include: VCSEL array and collimating superlens array; The VCSEL array comprises several VCSEL units; The collimating superlens array includes several collimating superlenses, and each of the collimating superlenses is arranged in a one-to-one correspondence with a number of VCSEL units to collimate the emitted beam of the VCSEL unit. The collimating superlens is composed of amorphous silicon cylinders of different radii, wherein the radius of each amorphous silicon cylinder is determined according to the position and phase of each position of the collimating superlens, so that the amorphous silicon cylinders of different radii are arranged according to the position and phase distribution of the collimating superlens; The position and phase of the collimating superlens at each location are optimized using a phase distribution function, which is: in, Indicates the position coordinates on the collimating superlens. This indicates the position and phase on the collimating superlens. Indicates the radius of the collimating superlens. Here, n represents the optimization coefficients; The position and phase of each position of the collimating superlens are optimized based on minimizing the divergence angle of the emitted light spot at that position. Based on the position and phase of each position of the collimating superlens, the radius of the amorphous silicon cylinder at the position is determined from the target phase and target transmittance of the transmitted light at different radii, wherein the target phase is continuous and its range is greater than or equal to 2π, and the target transmittance is greater than or equal to 0.
8.
2. The VCSEL array collimation system as described in claim 1, characterized in that, The collimating superlens is disposed within the VCSEL unit.
3. The VCSEL array collimation system as described in claim 1, characterized in that, It also includes a substrate and beam isolation elements; The collimating superlens is disposed on one side of the substrate, and the VCSEL unit is located on the other side of the substrate; The beam isolation element is disposed on the other side of the substrate in conjunction with the adjacent VCSEL unit to isolate the beam emitted by the adjacent VCSEL unit.
4. The VCSEL array collimation system as described in claim 3, characterized in that, It also includes a light-shielding film, which, together with the collimating superlens, is disposed on the empty area of the substrate other than the collimating superlens area, so as to block the emitted light beam from the empty area of the substrate other than the collimating superlens area, so that the emitted light beam only passes through the collimating superlens area.
5. A collimating superlens design method, characterized in that, The collimating superlens is composed of amorphous silicon cylinders of different radii arranged together. The design method of the collimating superlens includes the following steps: The position phase of the collimating superlens at each position is optimized by using a phase distribution function to minimize the divergence angle of the emitted light spot at that position, thus obtaining the position phase of the collimating superlens at each position; the phase distribution function is: ； in, Indicates the position coordinates on the collimating superlens. This indicates the position and phase on the collimating superlens. Indicates the radius of the collimating superlens. Here, n represents the optimization coefficients; Simulate the phase and transmittance of transmitted light from amorphous silicon cylinders at different radii to obtain the target phase and target transmittance, specifically including: Simulate the phase and transmittance of transmitted light from an amorphous silicon cylinder at different radii within a preset radius range; The simulated phase and transmittance are filtered according to preset filtering conditions to obtain target phase and target transmittance. The preset filtering conditions are: the target phase is continuous and its range is greater than or equal to 2π, and the target transmittance is greater than or equal to 0.
8. Based on the position and phase of each position of the collimating superlens, the radius of the amorphous silicon cylinder at each position of the collimating superlens is determined from the target phase and the target transmittance, so as to obtain the structural arrangement of amorphous silicon cylinders with different radii.
6. A collimating superlens, characterized in that, The collimating superlens is composed of amorphous silicon cylinders of different radii, and the structural arrangement of the amorphous silicon cylinders of different radii is designed using the method described in any one of claims 5.
Citation Information
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