Vehicle-mounted laser radar window depolarization antireflection film and preparation method thereof
By depositing a multi-layer film structure on the lidar window, the problem of dynamic changes in polarized light caused by changes in the incident angle of the lidar window was solved, achieving depolarization and anti-reflection effects over a wide angle range, thus improving the optical signal stability and environmental perception capabilities of the lidar.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-14
- Publication Date
- 2026-03-10
AI Technical Summary
The dynamic changes in polarization of light caused by the change in the incident angle of the lidar window under different postures lead to unstable transmission energy, affecting the consistency of detection, and the reflection echo of S-polarized light interferes with the perception of the real environment.
A multilayer film structure, including SiO2, TiO2, Al2O3 and antifouling AS film, is deposited on the lidar window. The thickness and refractive index of each film layer are controlled by a vacuum electron beam evaporation coating machine to achieve the antipolarization and antireflection effect.
It effectively eliminates polarization differences within the 0–60° incident angle range, improves the stability of lidar optical signals and environmental perception capabilities, and enhances detection consistency and real-world environmental perception capabilities.
Smart Images
Figure CN121634355A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of antireflection films, in particular to a vehicle-mounted laser radar window depolarization antireflection film and a preparation method thereof. BACKGROUND
[0002] The laser radar determines the distance by measuring the time difference and phase difference of the laser signal, and draws a clear 3D image of the target by using the multi-spectrometer imaging technology. The laser radar transmits and receives laser beams, analyzes the return time of the laser after encountering a target object, calculates the relative distance to the target object, and obtains the three-dimensional model and related data of the measured target by using the three-dimensional coordinates, reflectivity and texture of a large number of dense points on the surface of the target object collected in this process, establishes a three-dimensional point cloud map, and draws an environmental map to achieve the purpose of environmental perception. The laser radar window, as an important component of the laser radar, not only protects the internal structure, but also transmits and receives laser beams. According to the Fresnel reflection principle, near a certain angle (Brewster angle), the reflectivity of P-polarized light becomes very low and almost all transmits; while S-polarized light always has a high reflectivity.
[0003] When the laser radar angle of incidence (AOI) gradually increases from 0 to 60°, the difference between S-polarized light and P-polarized light gradually increases. If the radar is moving (such as being mounted on a moving vehicle), its own attitude (pitch, rotation) will change constantly, which causes the angle of incidence and the polarization direction of the laser beam relative to the laser radar window to change in real time, causing the laser beam to dynamically change between P and S polarization states, resulting in the transmitted energy through the window being large and small, making the light power transmitted to the outside unstable, affecting the detection consistency under different attitudes; at the same time, the part of S-polarized light reflected by the inner surface of the window when incident will not disappear, but will directly form a false echo signal inside the radar, seriously interfering with the perception of the real environment by the laser radar. SUMMARY
[0004] The purpose of the present application is to provide a vehicle-mounted laser radar window depolarization antireflection film and a preparation method thereof, which can achieve good depolarization effect when the angle of incidence (AOI) is in the range of 0-60°.
[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme:
[0006] The present application provides a vehicle-mounted laser radar window depolarization antireflection film, which comprises a first SIO2 film layer for being plated on the vehicle-mounted laser radar window, and a first TIO2 film layer, a second SIO2 film layer, an Al2O3 film layer, a second TIO2 film layer, a third SIO2 film layer and an anti-fouling AS film layer are sequentially plated on the first SIO2 film layer.
[0007] Further, the thickness of the first SIO2 film layer is 228.64±0.1nm, the thickness of the first TIO2 film layer is 30.41±0.1nm, the thickness of the second SIO2 film layer is 59.76±0.1nm, the thickness of the Al2O3 film layer is 213.82±0.1nm, the thickness of the second TIO2 film layer is 92.71±0.1nm, the thickness of the third SIO2 film layer is 324.85±0.1nm, and the thickness of the anti-fouling AS film layer is 10.00±0.1nm.
[0008] Further, under the condition that the test wavelength is 550nm and the light incidence angle is 0-60°, the refractive index of the first SIO2 film layer, the second SIO2 film layer and the third SIO2 film layer is 1.43-1.47; the refractive index of the first TIO2 film layer and the second TIO2 film layer is 2.35-2.45; the refractive index of the Al2O3 film layer is 1.65-1.69; and the refractive index of the anti-fouling AS film layer is 1.48-1.5.
[0009] The application also includes a preparation method of the anti-fouling film, which comprises the following steps: sequentially depositing the first SIO2 film layer, the first TIO2 film layer, the second SIO2 film layer, the Al2O3 film layer, the second TIO2 film layer, the third SIO2 film layer and the anti-fouling AS film layer on the surface of the vehicle-mounted laser radar window by using a vacuum electron beam evaporation coating machine.
[0010] The deposition rate of the first SIO2 film layer is 10 angstroms per second; the deposition rate of the first TIO2 film layer is 3.5 angstroms per second; the deposition rate of the second SIO2 film layer is 10 angstroms per second; the deposition rate of the Al2O3 film layer is 3 angstroms per second; the deposition rate of the second TIO2 film layer is 3.5 angstroms per second; the deposition rate of the third SIO2 film layer is 10 angstroms per second; and the deposition rate of the anti-fouling AS film layer is 8 angstroms per second.
[0011] Further, in the process of depositing the film layer by using the vacuum electron beam evaporation coating machine, a crystal oscillator film thickness controller is used to control the thickness of each film layer, and the thickness of the first SIO2 film layer is 228.64±0.1nm; the thickness of the first TIO2 film layer is 30.41±0.1nm; the thickness of the second SIO2 film layer is 59.76±0.1nm; the thickness of the Al2O3 film layer is 213.82±0.1nm; the thickness of the second TIO2 film layer is 92.71±0.1nm; the thickness of the third SIO2 film layer is 324.85±0.1nm; and the thickness of the anti-fouling AS film layer is 10.00±0.1nm.
[0012] Further, the vacuum degree in the process of depositing the film layer by using the vacuum electron beam evaporation coating machine is 2×10 -3Pa, the vacuum chamber environment heating temperature is 80℃.
[0013] Further, the first SIO2 film layer, the first TIO2 film layer, the second SIO2 film layer, the Al2O3 film layer, the second TIO2 film layer and the third SIO2 film layer are deposited by using ions generated by an ion source to bombard the growing film layer, and the ion source is turned off before the deposition of the anti-fouling AS film layer.
[0014] Further, before the deposition of the surface of the vehicle-mounted laser radar window, the vehicle-mounted laser radar window is cleaned by using an ultrasonic cleaning machine, and then baked, the baking temperature is 80±5℃, and the baking time is 1 hour.
[0015] Compared with the prior art, the application has the advantages of simple structure, good elimination of deviation effect (reduction of P-polarized light and S-polarized light difference) in the AOI=0-60° incident angle range, and also realizes the effect of antireflection and anti-reflection, solves the interference of the polarization phenomenon of 0-60° incident light on the laser radar, and improves the optical signal stability of the laser radar system and the perception ability to the real environment. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 The film layer arrangement diagram of the application.
[0017] Figure 2 The reflectivity of the application at an incident angle of 0°.
[0018] Figure 3 The transmittance of the application at an incident angle of 0°.
[0019] Figure 4 The reflectivity of P light and S light of the application at an incident angle of 30°.
[0020] Figure 5 The reflectivity of P light and S light of the application at an incident angle of 60°.
[0021] 00-vehicle-mounted laser radar window; 1-first SIO2 film layer; 2-first TIO2 film layer; 3-second SIO2 film layer; 4-Al2O3 film layer; 5-second TIO2 film layer; 6-third SIO2 film layer; 7-anti-fouling AS film layer. DETAILED DESCRIPTION
[0022] The technical solutions of the application will be further described below in combination with specific embodiments. It should be understood that the following embodiments are only illustrative and explanatory of the application, and should not be interpreted as limiting the scope of protection of the application. Any technology realized based on the above description of the application is covered within the scope of protection intended by the application.
[0023] As Figure 1As shown, in an embodiment of the present application, a vehicle-mounted laser radar window depolarization antireflection film, comprising a first SIO2 film layer 1 for being plated on the vehicle-mounted laser radar window 00, a first TIO2 film layer 2, a second SIO2 film layer 3, an Al2O3 film layer 4, a second TIO2 film layer 5, a third SIO2 film layer 6 and an anti-fouling AS film layer 7 are sequentially plated on the first SIO2 film layer 1; the interference of the laser radar window 0-60° incident light polarization phenomenon on the laser radar is solved, and the perception performance of the laser radar to the real environment is improved.
[0024] In an embodiment of the present application, the material of the vehicle-mounted laser radar window 00 is PC.
[0025] In an embodiment of the present application, the thickness of the first SIO2 film layer 1 is 228.64±0.1nm, the thickness of the first TIO2 film layer 2 is 30.41±0.1nm, the thickness of the second SIO2 film layer 3 is 59.76±0.1nm, the thickness of the Al2O3 film layer 4 is 213.82±0.1nm, the thickness of the second TIO2 film layer 5 is 92.71±0.1nm, the thickness of the third SIO2 film layer 6 is 324.85±0.1nm, and the thickness of the anti-fouling AS film layer 7 is 10.00±0.1nm.
[0026] In an embodiment of the present application, under the condition that the test wavelength is 550nm and the light incident angle is 0-60°, the refractive index of the first SIO2 film layer 1, the second SIO2 film layer 3 and the third SIO2 film layer 6 is 1.43-1.47; the refractive index of the first TIO2 film layer 2 and the second TIO2 film layer 5 is 2.35-2.45; the refractive index of the Al2O3 film layer 4 is 1.65-1.69; and the refractive index of the anti-fouling AS film layer 7 is 1.48-1.5.
[0027] The present application provides another embodiment: a preparation method of an antireflection film, wherein a vacuum electron beam evaporation coating machine is used to sequentially deposit the first SIO2 film layer 1, the first TIO2 film layer 2, the second SIO2 film layer 3, the Al2O3 film layer 4, the second TIO2 film layer 5, the third SIO2 film layer 6 and the anti-fouling AS film layer 7 on the surface of the vehicle-mounted laser radar window 00.
[0028] The deposition rate of the first SIO2 film layer 1 is 10 angstroms per second; the deposition rate of the first TIO2 film layer 2 is 3.5 angstroms per second; the deposition rate of the second SIO2 film layer 3 is 10 angstroms per second; the deposition rate of the Al2O3 film layer 4 is 3 angstroms per second; the deposition rate of the second TIO2 film layer 5 is 3.5 angstroms per second; the deposition rate of the third SIO2 film layer 6 is 10 angstroms per second; and the deposition rate of the anti-fouling AS film layer 7 is 8 angstroms per second.
[0029] In an embodiment of the present application, during the process of depositing the film layers by using the vacuum electron beam evaporation coating machine, the thickness of each film layer is controlled by using the crystal oscillator film thickness controller, the thickness of the first SIO2 film layer 1 is 228.64±0.1 nm, the thickness of the first TIO2 film layer 2 is 30.41±0.1 nm, the thickness of the second SIO2 film layer 3 is 59.76±0.1 nm, the thickness of the Al2O3 film layer 4 is 213.82±0.1 nm, the thickness of the second TIO2 film layer 5 is 92.71±0.1 nm, the thickness of the third SIO2 film layer 6 is 324.85±0.1 nm, and the thickness of the anti-fouling AS film layer 7 is 10.00±0.1 nm. The film layer thickness is controlled by using the crystal oscillator film thickness controller to achieve high precision.
[0030] In an embodiment of the present application, when the film layers are deposited by using the vacuum electron beam evaporation coating machine, the vacuum degree is 2×10 -3 Pa, and the environmental heating temperature of the vacuum chamber is 80℃.
[0031] In an embodiment of the present application, when the first SIO2 film layer 1, the first TIO2 film layer 2, the second SIO2 film layer 3, the Al2O3 film layer 4, the second TIO2 film layer 5, and the third SIO2 film layer 6 are deposited, the ion source is used to bombard the growing film layer, and the ion source is turned off before the anti-fouling AS film layer 7 is deposited, so as to improve the adhesion and density of the film layer.
[0032] In an embodiment of the present application, before the surface of the vehicle-mounted laser radar window 00 is deposited, the vehicle-mounted laser radar window is cleaned by using an ultrasonic cleaning machine, and then is baked, the baking temperature is 80±5℃, and the baking time is 1 hour; the internal moisture of the vehicle-mounted laser radar window is removed, the adhesion of the film layer is improved, the baking temperature is too low, the moisture is not easy to remove, and too high is easy to cause the deformation of the vehicle-mounted laser radar window.
[0033] In an embodiment of the present application, the preparation method of the depolarization and anti-reflection film of the vehicle-mounted laser radar window comprises the following steps:
[0034] (1) the vehicle-mounted laser radar window 00 is cleaned by using an ultrasonic cleaning machine, and then is baked, the baking temperature is 80±5℃, and the baking time is 1 hour;
[0035] (2) the baked vehicle-mounted laser radar window is placed into a vacuum electron beam evaporation coating machine, the vacuum degree of the vacuum electron beam evaporation coating machine is set to 2×10 -3 Pa, the environmental heating temperature of the vacuum chamber is 80℃, the ion source is turned on, and the following six film layers are sequentially deposited on the surface of the baked vehicle-mounted laser radar window, and the thickness of each film layer is controlled by using a crystal oscillator film thickness controller:
[0036] A. Plating the first film layer (i.e. the first S1O2 film layer 1) :
[0037] The electron gun filament of the vacuum electron beam evaporation coater is kept in a heated, vacuum state, and the electron stream forms a fine beam and bombards the silicon dioxide material, causing the silicon dioxide material to evaporate in a molecular state and adhere to the surface of the vehicle-mounted laser radar window 00, so as to plate the first S1O2 film layer 1 with a thickness of 228.64 ± 0.1 nm on the surface of the vehicle-mounted laser radar window 00 at a deposition rate of 10 angstroms per second;
[0038] B. Plating the second film layer (i.e. the first T1O2 film layer 2) :
[0039] The electron gun filament of the vacuum electron beam evaporation coater is kept in a heated, vacuum state, and the electron stream forms a fine beam and bombards the titanium dioxide material, causing the titanium dioxide material to evaporate in a molecular state and adhere to the surface of the first S1O2 film layer 1 on the surface of the vehicle-mounted laser radar window 00, so as to plate the first T1O2 film layer 2 with a thickness of 30.41 ± 0.1 nm on the surface of the first S1O2 film layer 1 at a deposition rate of 3.5 angstroms per second;
[0040] C. Plating the third film layer (i.e. the second S1O2 film layer 3) :
[0041] The electron gun filament of the vacuum electron beam evaporation coater is kept in a heated, vacuum state, and the electron stream forms a fine beam and bombards the silicon dioxide material, causing the silicon dioxide material to evaporate in a molecular state and adhere to the surface of the first T1O2 film layer 2 on the surface of the vehicle-mounted laser radar window 00, so as to plate the second S1O2 film layer 3 with a thickness of 59.76 ± 0.1 nm on the surface of the first T1O2 film layer 2 at a deposition rate of 10 angstroms per second;
[0042] D. Plating the fourth film layer (i.e. the Al2O3 film layer 4) :
[0043] The electron gun filament of the vacuum electron beam evaporation coater is kept in a heated, vacuum state, and the electron stream forms a fine beam and bombards the aluminum trioxide material, causing the aluminum trioxide material to evaporate in a molecular state and adhere to the surface of the second S1O2 film layer 3 on the surface of the vehicle-mounted laser radar window 00, so as to plate the Al2O3 film layer 4 with a thickness of 213.82 ± 0.1 nm on the surface of the second S1O2 film layer 3 at a deposition rate of 3 angstroms per second;
[0044] E. Plating the fifth film layer (i.e. the second T1O2 film layer 5) :
[0045] The electron gun wire of the vacuum electron beam evaporation coating machine is kept in a heated and vacuum state. The electron beam forms a fine beam and bombards the titanium dioxide material, causing the titanium dioxide material to evaporate into a molecular state and adhere to the surface of the Al2O3 film layer 4 on the surface of the vehicle lidar window 00. At a deposition rate of 3.5 Å / s, a second TiO2 film layer 5 with a thickness of 92.71±0.1nm is deposited on the surface of the Al2O3 film layer 4.
[0046] F. Deposit the sixth film layer (i.e., the third SiO2 film layer 6 mentioned above):
[0047] The electron gun wire of the vacuum electron beam evaporation coating machine is kept in a heated and vacuum state. The electron beam forms a fine beam and bombards the silicon dioxide material, causing the silicon dioxide material to evaporate into a molecular state and adhere to the surface of the second TiO2 film layer 5 on the surface of the vehicle-mounted lidar window 00. At a deposition rate of 10 Å / s, a third SiO2 film layer 6 with a thickness of 324.85±0.1nm is deposited on the surface of the second TiO2 film layer 5.
[0048] (3) Turn off the ion source and deposit the seventh film layer (i.e., the antifouling AS film layer 7 mentioned above):
[0049] The ion source is turned off, and the electron gun wire of the vacuum electron beam evaporation coating machine is kept in a heated and vacuum state. The electron beam forms a fine beam and bombards the anti-fouling AS material, causing the anti-fouling AS material to evaporate into a molecular state and adhere to the surface of the third SiO2 film layer 6 on the surface of the vehicle-mounted LiDAR window 00. At a deposition rate of 8 Å / s, an anti-fouling AS film layer 7 with a thickness of 10.00±0.1nm is deposited on the surface of the third SiO2 film layer 6.
[0050] The anti-polarization anti-reflection film for the vehicle-mounted lidar window of this invention can achieve ultra-low reflection when the incident light angle AOI = 0°, such as... Figure 2 As shown, the average reflectivity of the vehicle-mounted lidar in the 1520-1580nm operating band is less than 0.02%, such as... Figure 3 As shown, the average transmittance of the vehicle-mounted lidar in the 1520-1580nm operating band is higher than 99%, which has a good anti-reflection and anti-reflection effect and can improve the optical performance of the lidar.
[0051] It can also eliminate the polarization phenomenon of light when incident at large angles, avoiding interference from the polarization problem of light incident at large angles with the lidar's perception of the real environment. For example... Figure 4 As shown, when the incident angle AOI = 30°, the average reflectivity of S-ray is 0.046%, and the average reflectivity of P-ray is 0.127%, with a difference of <0.1% between P-ray and S-ray. Figure 5 As shown, when the incident angle AOI = 60°, the average reflectivity of S-ray is 3.0%, the average reflectivity of P-ray is 3.0%, and the difference between P-ray and S-ray is <0.1%.
[0052] Different incident angle light rays can achieve P light and S light difference of less than 0.1% after passing through the laser radar window, the depolarization and anti-reflection film of the vehicle-mounted laser radar window provided by the application not only has good anti-reflection effect, but also can achieve excellent depolarization effect, which can greatly improve the perception ability of the laser radar to the real environment and improve the driving safety.
[0053] Although the specific embodiments of the application are described above, those skilled in the art should understand that the specific examples described are only illustrative, and are not intended to limit the scope of the application, and the modifications and changes made by those skilled in the art in accordance with the spirit of the application should be covered within the scope of the claims of the application.
Claims
1. A vehicle-mounted laser radar view window depolarization antireflection film, characterized by: The first SIO2 film layer is coated on the vehicle-mounted laser radar window, and the first SIO2 film layer is sequentially coated with a first TIO2 film layer, a second SIO2 film layer, an Al2O3 film layer, a second TIO2 film layer, a third SIO2 film layer, and an anti-fouling AS film layer.
2. The polarization-uncompensating antireflection film for a lidar window of a vehicle according to claim 1, characterized by: The thickness of the first SIO2 film layer is 228.64±0.1nm, the thickness of the first TIO2 film layer is 30.41±0.1nm, the thickness of the second SIO2 film layer is 59.76±0.1nm, the thickness of the Al2O3 film layer is 213.82±0.1nm, the thickness of the second TIO2 film layer is 92.71±0.1nm, the thickness of the third SIO2 film layer is 324.85±0.1nm, and the thickness of the anti-fouling AS film layer is 10.00±0.1nm.
3. The polarization-uncompensating antireflection film for a lidar window of a vehicle according to claim 1, characterized by: The refractive index of the first SIO2 film layer, the second SIO2 film layer, and the third SIO2 film layer is 1.43-1.47 at a test wavelength of 550nm and an incident angle of 0-60°; the refractive index of the first TIO2 film layer and the second TIO2 film layer is 2.35-2.45; the refractive index of the Al2O3 film layer is 1.65-1.69; and the refractive index of the anti-fouling AS film layer is 1.48-1.
5.
4. The method of claim 1-3, wherein: The first SIO2 film layer, the first TIO2 film layer, the second SIO2 film layer, the Al2O3 film layer, the second TIO2 film layer, the third SIO2 film layer, and the anti-fouling AS film layer are sequentially deposited on the surface of the vehicle-mounted laser radar window by using a vacuum electron beam evaporation coating machine. The deposition rate of the first SIO2 film layer is 10 angstroms per second; the deposition rate of the first TIO2 film layer is 3.5 angstroms per second; the deposition rate of the second SIO2 film layer is 10 angstroms per second; the deposition rate of the Al2O3 film layer is 3 angstroms per second; the deposition rate of the second TIO2 film layer is 3.5 angstroms per second; the deposition rate of the third SIO2 film layer is 10 angstroms per second; and the deposition rate of the anti-fouling AS film layer is 8 angstroms per second.
5. The method of claim 4, wherein: In the process of depositing the film layer by using the vacuum electron beam evaporation coating machine, a crystal oscillator film thickness controller is used to control the thickness of each film layer, the thickness of the first SIO2 film layer is 228.64±0.1nm; the thickness of the first TIO2 film layer is 30.41±0.1nm; the thickness of the second SIO2 film layer is 59.76±0.1nm; the thickness of the Al2O3 film layer is 213.82±0.1nm; the thickness of the second TIO2 film layer is 92.71±0.1nm; the thickness of the third SIO2 film layer is 324.85±0.1nm; and the thickness of the anti-fouling AS film layer is 10.00±0.1nm.
6. The method of claim 4, wherein: The vacuum degree during the deposition of the film layer by the vacuum electron beam evaporation coating machine is 2x10 -3 Pa, and the environmental heating temperature of the vacuum chamber is 80°C.
7. The method of claim 4, wherein the method further comprises: The ion source generated ion is used to bombard the growing film layer when the first SIO2 film layer, the first TIO2 film layer, the second SIO2 film layer, the Al2O3 film layer, the second TIO2 film layer, and the third SIO2 film layer are deposited, and the ion source is turned off before the anti-fouling AS film layer is deposited.
8. The method of claim 4, wherein: Before the surface of the vehicle-mounted laser radar window is deposited, the vehicle-mounted laser radar window is cleaned by using an ultrasonic cleaning machine, and then is baked, the temperature of the baking is 80±5 DEG C, and the time length is 1 hour.