An ultra-wide angle penetrating near-infrared light AR film

Abstract

The present invention discloses an ultra-wide-angle near-infrared light (AR) film, comprising a substrate and an AR film coated on the substrate. The AR film comprises, from the inside out, a first high-refractive-index film, a first low-refractive-index film, a second high-refractive-index film, a second low-refractive-index film, a third high-refractive-index film, a third low-refractive-index film, a fourth high-refractive-index film, a fifth high-refractive-index film, a fourth low-refractive-index film, a sixth high-refractive-index film, a seventh high-refractive-index film, a fifth low-refractive-index film, an eighth high-refractive-index film, a ninth high-refractive-index film, and a sixth low-refractive-index film. The present invention has a simple structure and low film layer stress, making it very suitable for industrial mass production.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical coatings, and in particular relates to an AR film that penetrates near-infrared light at an ultra-wide angle. Background Art

[0002] With the development of infrared technology, infrared LEDs and infrared lasers with wavelengths such as 850nm, 905nm, 940nm, 1064nm, and 1550nm are being increasingly widely used in biometrics and automatic ranging.

[0003] Optical glass or plastics with a refractive index of 1.5 to 1.9 experience a reflection loss of approximately 4.0% to 9.6% on each surface. This results in light energy loss within the optical system and multiple reflections from various internal surfaces, causing stray light. To reduce or eliminate reflected light from optical surfaces, thereby increasing light transmission from optical components and reducing or eliminating stray light in the system, an anti-reflection coating (also known as AR coating) is applied to the optical surface. Anti-reflection coatings are widely used in digital, surveillance, astronomy, automotive, and machine vision applications.

[0004] Biometric identification and automatic ranging infrared optical systems often require good light transmittance and low stray light at both 0° and high-angle incidence. Unfortunately, due to the physical properties of optical films, the equivalent refractive index and film thickness of the film layer change significantly for light incident at different angles, and the coating curve will shift. Conventional optical films find it difficult to achieve a reduction in reflectivity at both 0° and high-angle incidence. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings, thereby providing an ultra-wide angle penetrating near-infrared light AR film that solves the large difference in near-infrared light transmittance in different angle ranges in the prior art.

[0006] In order to achieve the above-mentioned design purpose, the technical solution adopted by the present invention is: an ultra-wide-angle penetrating near-infrared light AR film, comprising a substrate and an AR film coated on the substrate, wherein the AR film is composed of a first high refractive index film, a first low refractive index film, a second high refractive index film, a second low refractive index film, a third high refractive index film, a third low refractive index film, a fourth high refractive index film, a fifth high refractive index film, a fourth low refractive index film, a sixth high refractive index film, a seventh high refractive index film, a fifth low refractive index film, an eighth high refractive index film, a ninth high refractive index film, and a sixth low refractive index film from the inside to the outside.

[0007] The first high refractive index film is coated on the substrate layer, and the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 50-103nm; the first low refractive index film is coated on the first high refractive index film, and the film material is SIO2 or MGF2, with a thickness of 30-85nm; the second high refractive index film is coated on the first low refractive index film, and the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 100-200nm; the second low refractive index film is coated on the second high refractive index film, and the film material is SIO2 or MGF2, with a thickness of 80-150nm m; the third high refractive index film is coated on the second low refractive index film, the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, Ta2O5, and the thickness is 65-120nm; the third low refractive index film is coated on the third high refractive index film, the film material is SIO2 or MGF2, and the thickness is 70-140nm; the fourth high refractive index film is coated on the third low refractive index film, the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, Ta2O5, and the thickness is 90-170nm; the fifth high refractive index film is coated on the fourth high refractive index film, the film material is H4, TIO2, ZrO2, Hf O2, Nb2O3, Ta2O5, with a thickness of 55-120nm; the fourth low refractive index film is coated on the fifth high refractive index film, the film material is SIO2 or MGF2, with a thickness of 270-540nm; the sixth high refractive index film is coated on the fourth low refractive index film, the film material is H4, TIO2, ZrO2, HfO2, Nb2O3, Ta2O5, with a thickness of 100-220nm; the seventh high refractive index film is coated on the sixth high refractive index film, the film material is H4, TIO2, ZrO2, HfO2, Nb2O3, Ta2O5, with a thickness of 70-170nm; the fifth low refractive index film It is coated on the seventh high refractive index film, and the film layer material is SIO2 or MGF2, with a thickness of 20-60nm; the eighth high refractive index film is coated on the fifth low refractive index film, and the film layer material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 14-30nm; the ninth high refractive index film is coated on the eighth high refractive index film, and the film layer material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 90-190nm; the sixth low refractive index film is coated on the ninth high refractive index film, and the film layer material is any one of SIO2 or MGF2, with a thickness of 180-340nm.

[0008] The refractive index of the low-refractive-index film is between 1.35 and 1.6.

[0009] The refractive index of the high refractive index film is between 1.7 and 2.65.

[0010] The substrate is any one of optical plastic and optical glass.

[0011] When the substrate is optical glass, the AR film has a maximum reflectivity of less than 0.2% at an incident angle of 0°-30° in the near-infrared band, a maximum reflectivity of less than 0.6% at an incident angle of 50°, and a maximum reflectivity of less than 0.8% at an incident angle of 60°.

[0012] When the substrate is optical plastic, the AR film has a maximum reflectivity of less than 0.2% at an incident angle of 0°-30° in the near-infrared band, a maximum reflectivity of less than 0.8% at an incident angle of 50°, and a maximum reflectivity of less than 1.6% at an incident angle of 60°.

[0013] The AR film can achieve a near-infrared spectrum with an incident angle of 0-60° and a maximum reflectivity of <1.6%. The near-infrared light includes but is not limited to 905nm, 940nm, 1064nm, and 1550nm.

[0014] The present invention provides an ultra-wide-angle near-infrared (AR) film system. By utilizing the wide-angle matching concept of the optical admittance of two or more common film materials, the system achieves extremely low reflectivity at 0-60° incidence in near-infrared bands such as 905nm, 940nm, 1064nm, and 1550nm. When the substrate is optical glass, the maximum reflectivity is less than 0.2% at an incident angle of 0°-30°, less than 0.6% at an incident angle of 50°, and less than 0.8% at an incident angle of 60°. When the substrate is optical plastic, the AR film system achieves maximum reflectivity of less than 0.2% at an incident angle of 0°-30°, less than 0.8% at an incident angle of 50°, and less than 1.6% at an incident angle of 60° in the four aforementioned near-infrared bands. This effectively reduces stray light in the system and mitigates the effects of ghosting. The present invention's design scheme offers a simple structure and low film stress, making it ideal for industrial mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic structural diagram of an AR film system according to an optional embodiment of the present invention;

[0016] Figure 2 A schematic diagram comparing the 0°-60° reflectivity of an AR film system on an optical plastic substrate according to an optional embodiment of the present invention and the 0°-60° reflectivity of a conventional film system;

[0017] Figure 3 A schematic diagram comparing the 0°-60° reflectivity of an AR film system on an optical glass substrate according to an optional embodiment of the present invention and the 0°-60° reflectivity of a conventional film system;

[0018] Figure 4 Schematic diagram comparing the admittance diagram of an AR film system according to an optional embodiment of the present invention and the admittance diagram of a conventional film system;

[0019] Figure 5 Schematic diagram of the reflectivity curves at 0°-60° in the near-infrared light bands of 905nm, 940nm, 1064nm, and 1550nm when the substrate of the present invention is an optical plastic;

[0020] Figure 6 The figure shows a schematic diagram of the reflectivity curves of 0°-60° in infrared light bands such as 905nm, 940nm, 1064nm, and 1550nm when the substrate of the present invention is optical glass. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Figure 1-6 As shown: An ultra-wide-angle penetrating near-infrared light AR film, comprising a substrate and an AR film coated on the substrate, wherein the AR film is composed of, from the inside to the outside, a first high refractive index film (H1), a first low refractive index film (L1), a second high refractive index film (H2), a second low refractive index film (L2), a third high refractive index film (H3), a third low refractive index film (L3), a fourth high refractive index film (H4), a fifth high refractive index film (H5), a fourth low refractive index film (L4), a sixth high refractive index film (H6), a seventh high refractive index film (H7), a fifth low refractive index film (L5), an eighth high refractive index film (H8), a ninth high refractive index film (H9), and a sixth low refractive index film (L6).

[0022] The first high refractive index film (H1) is coated on the substrate layer, and the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 50-103nm. The material has excellent mechanical properties and low loss absorption, and can improve the bonding strength of subsequent film layers; the first low refractive index film (L1) is coated on the first high refractive index film (H1), and the film material is SIO2 or MGF2, with a thickness of 30-85nm, and is used to increase adhesion and reduce reflectivity; the second high refractive index film (H2) is coated on the first low refractive index film (L1), and the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 100-2 00nm, used to increase transmittance; the second low refractive index film (L2) is plated on the second high refractive index film (H2), the film material is SIO2 or MGF2, the thickness is 80-150nm, used to increase adhesion and reduce reflectivity; the third high refractive index film (H3) is plated on the second low refractive index film (L2), the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, Ta2O5, the thickness is 65-120nm, used to increase transmittance; the third low refractive index film (L3) is plated on the third high refractive index film (H3), the film material is SIO2 or MGF2, the thickness is 70-140nm, used to increase adhesion and reduce reflectivity; the The fourth high refractive index film (H4) is plated on the third low refractive index film (L3), and the film layer material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 90-170nm, and is used to increase the transmittance; the fifth high refractive index film (H5) is plated on the fourth high refractive index film (H4), and the film layer material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 55-120nm, and is used to increase the transmittance; the fourth low refractive index film (L4) is plated on the fifth high refractive index film (H5), and the film layer material is SIO2 or MGF2, with a thickness of 270-540nm, and is used to increase the adhesion and reduce the reflectivity; The sixth high refractive index film (H6) is plated on the fourth low refractive index film (L4), and the film layer material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 100-220nm, and is used to increase transmittance; the seventh high refractive index film (H7) is plated on the sixth high refractive index film (H6), and the film layer material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 70-170nm, and is used to increase transmittance; the fifth low refractive index film (L5) is plated on the seventh high refractive index film (H7), and the film layer material is SIO2 or MGF2, with a thickness of 20-60nm, and is used to increase adhesion and reduce reflectivity;The eighth high-refractive-index film (H8) is deposited on the fifth low-refractive-index film (L5). The film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 14-30 nm, and is used to increase transmittance. The ninth high-refractive-index film (H9) is deposited on the eighth high-refractive-index film (H8). The film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 90-190 nm, and is used to increase transmittance. The sixth low-refractive-index film (L6) is deposited on the ninth high-refractive-index film (H9). The film material is either SIO2 or MGF2, with a thickness of 180-340 nm, and is used to increase film hardness and reduce reflectivity.

[0023] The refractive index of the low-refractive-index film is between 1.35 and 1.6.

[0024] The refractive index of the high refractive index film is between 1.7 and 2.65.

[0025] The substrate is any one of optical plastic and optical glass.

[0026] When the substrate is optical glass, the AR film has a maximum reflectivity of less than 0.2% at an incident angle of 0°-30° in the near-infrared band, a maximum reflectivity of less than 0.6% at an incident angle of 50°, and a maximum reflectivity of less than 0.8% at an incident angle of 60°.

[0027] When the substrate is optical plastic, the AR film has a maximum reflectivity of less than 0.2% at an incident angle of 0°-30° in the near-infrared band, a maximum reflectivity of less than 0.8% at an incident angle of 50°, and a maximum reflectivity of less than 1.6% at an incident angle of 60°.

[0028] The AR film can achieve a near-infrared spectrum with an incident angle of 0-60° and a maximum reflectivity of <1.6%. The near-infrared light includes but is not limited to 905nm, 940nm, 1064nm, and 1550nm.

Claims

1. An ultra-wide-angle near-infrared light penetration AR film, comprising a substrate and an AR film coated on the substrate, wherein the AR film is composed, from inside to outside, of a first high-refractive-index film, a first low-refractive-index film, a second high-refractive-index film, a second low-refractive-index film, a third high-refractive-index film, a third low-refractive-index film, a fourth high-refractive-index film, a fifth high-refractive-index film, a fourth low-refractive-index film, a sixth high-refractive-index film, a seventh high-refractive-index film, a fifth low-refractive-index film, an eighth high-refractive-index film, a ninth high-refractive-index film, and a sixth low-refractive-index film; the first high-refractive-index film is coated on the substrate layer, and the film layer material is one of H4, TiO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 50-103 nm; the first low-refractive-index film is coated on the first high-refractive-index film, and the film layer material is SiO2 or MGF2 , thickness 30-85nm; the second high refractive index film is coated on the first low refractive index film, the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, Ta2O5, and the thickness is 100-200nm; the second low refractive index film is coated on the second high refractive index film, the film material is SIO2 or MGF2, and the thickness is 80-150nm; the third high refractive index film is coated on the second low refractive index film, the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, Ta2O5, and the thickness is 65-120nm; the third low refractive index film is coated on the third high refractive index film, the film material is SIO2 or MGF2 , thickness 70-140nm; the fourth high refractive index film is coated on the third low refractive index film, and the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 90-170nm; the fifth high refractive index film is coated on the fourth high refractive index film, and the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 55-120nm; the fourth low refractive index film is coated on the fifth high refractive index film, and the film material is SIO2 or MGF2 , thickness 270-540nm; the sixth high refractive index film is coated on the fourth low refractive index film, the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, and the thickness is 100-220nm; the seventh high refractive index film is coated on the sixth high refractive index film, the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, and the thickness is 70-170nm; the fifth low refractive index film is coated on the seventh high refractive index film, the film material is SIO2 or MGF2, and the thickness is 20-60nm; the eighth high refractive index film is coated on the fifth low refractive index film, the film material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, and the thickness is 14-30nm;The ninth high-refractive-index film is deposited on the eighth high-refractive-index film, and the film layer material is one of H4, TIO2, ZrO2, HfO2, Nb2O3, and Ta2O5, with a thickness of 90-190 nm. The sixth low-refractive-index film is deposited on the ninth high-refractive-index film, and the film layer material is either SIO2 or MGF2, with a thickness of 180-340 nm. When the substrate is optical glass, the AR film has a near-infrared wavelength range with a maximum reflectivity of less than 0.2% at an incident angle of 0°-30°, a maximum reflectivity of less than 0.6% at an incident angle of 50°, and a maximum reflectivity of less than 0.8% at an incident angle of 60°.

2. The ultra-wide-angle near-infrared light AR film according to claim 1, wherein: The refractive index of the low-refractive-index film is between 1.35 and 1.

6.

3. The ultra-wide-angle near-infrared light AR film according to claim 1, characterized in that: The refractive index of the high refractive index film is between 1.7 and 2.

65.

4. The ultra-wide-angle near-infrared light AR film according to claim 1, wherein: The substrate is any one of optical plastic and optical glass.

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