WIDE ANGLE APPLICATION HIGH REFLECTIVE MIRROR

Abstract

Provided is a wide angle application high reflective mirror having a reflection band partially overlapping in a wavelength range of 800-4000 nm. The mirror comprises a film system in which a plurality of high refractive index film layers and a plurality of low refractive index film layers that are alternately stacked, and the material of the high refractive index film layer is one of SiH, SiO.sub.xH.sub.y, or SiO.sub.xN.sub.y, or a mixture thereof. The highly reflective mirror can achieve a reflectance greater than 99% with an incident angle ranging from 0 to 60 degrees over a large angle range.

Claims

1. A wide angle application high reflective mirror having a reflection band partially overlapping in a wavelength range of 800 to 4000 nm, wherein the reflective mirror comprises: a plurality of high refractive index film layers and a plurality of low refractive index film layers alternately stacked; the material of the high refractive index film layer is SiH, SiOxHy, or SiOxNy, or a mixture thereof, and each of the high refractive index film layers has a refractive index of greater than 3 in a wavelength range of 800 to 4000 nm. The reflection band has a reflectance of greater than 99% with an incident angle ranging from 0 to 60 degrees over a large angle range.

2. The wide angle application high reflective mirror according to claim 1, wherein the high refractive index film layer has a refractive index of greater than 3.5 in a wavelength range of 800 to 1100 nm.

3. The wide angle application high reflective mirror according to claim 1, wherein the material of the low refractive index film layer is one or a mixture of two or more of TiO.sub.2, Nb.sub.2O.sub.5, Ta.sub.2O.sub.5, SiO.sub.2, SixNy.

4. The wide angle application high reflective mirror according to claim 1, wherein a reflection band partially overlapping with a wavelength range of 800 to 4000 nm is provided, and the reflection band has a reflectance of greater than 99% in an incident angle range of 0 to 80 degrees.

5. The wide angle application high reflective mirror according to claim 1, wherein the film system further comprises a metal film layer located on the innermost side of the film system, and the metal layer is one or a mixture of two or more of Cr, Ta, Ti, Nb, Ni, Au, Ag, Cu, Al.

6. The wide angle application high reflective mirror according to claim 1, wherein it further comprises a substrate for carrying a film system, and the substrate material is one or a mixture of two or more of a silicon material, silica-based glass, plastic, sapphire, silicon carbide, and tempered glass.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0014] FIG. 1 is a schematic diagram of a structure of the present invention:

[0015] FIG. 2 is a diagram of a relationship between of a reflectance and a wavelength according to Embodiment 1 of the present invention;

[0016] FIG. 3 is a diagram of a relationship between an average reflectance of a reflection band and an incident angle according to Embodiment 1 of the present invention;

[0017] FIG. 4 is a diagram of a relationship between of a reflectance and a wavelength according to Comparative Example 1 of the present invention;

[0018] FIG. 5 is a diagram of a relationship between an average reflectance of a reflection band and an incident angle according to Comparative Example 1 of the present invention:

[0019] FIG. 6 is a diagram of a relationship between of a reflectance and a wavelength according to Comparative Example 2 of the present invention; and

[0020] FIG. 7 is a diagram of a relationship between an average reflectance of a reflection band and an incident angle according to Comparative Example 2 of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0021] The invention will be further described below in combination with embodiments and comparative examples.

[0022] As shown in FIG. 1, a wide angle application high reflective mirror of the present invention has a reflection band partially overlapping in a wavelength range of 800 to 4000 nm, where the reflective mirror includes: a plurality of high refractive index film layers 1 and a plurality of low refractive index film layers 2 alternately stacked; the material of high refractive index film layers 1 is SiH, SiOxHy, or SiOxNy, or a mixture thereof, and each of the high refractive index film layers 2 has a refractive index of greater than 3 in a wavelength range of 800 to 4000 nm. The reflection band has a reflectance of greater than 99% with an incident angle ranging from 0 to 60 degrees over a large angle range.

[0023] The high refractive index film layer 2 has a refractive index of greater than 3.5 in the wavelength range of 800 to 1100 nm.

[0024] The material of the low refractive index film layer 1 is one or a mixture of two or more of TiO.sub.2, Nb.sub.2O.sub.5, Ta.sub.2O.sub.5, SiO.sub.2, SixNy.

[0025] The film layer further includes a metal film layer located on the innermost side of the film system, and the metal layer is one or a mixture of two or more of Cr, Ta, Ti, Nb, Ni, Au, Ag, Cu, Al.

[0026] The high reflective mirror further includes a substrate for carrying a film system, and the substrate material is one or a mixture of two or more of a silicon material, silica-based glass, plastic, sapphire, silicon carbide, and tempered glass.

Embodiment 1

[0027] As shown in one of FIG. 1 to FIG. 3, a wide angle application high reflective mirror has a high reflection band in a range of 850 to 950 nm, and the structure thereof includes: a film system formed by a plurality of high refractive index film layers 1 and a plurality of low refractive index film layers 2 that are alternately stacked.

[0028] The material of the high refractive index film layer is SiH, and the refractive index thereof near 900 nm is 3.6.

[0029] The material of the low refractive index film layer is SiO.sub.2, and the refractive index thereof near 900 nm is 1.48.

[0030] The material of the substrate is a common K9 optical glass.

[0031] The reflection band of the present invention has a reflectance of greater than 99% with an incident angle ranging from 0 to 80 degrees. Furthermore, it can meet the reliability requirements of abrasion resistance, and high temperature and high humidity resistance of communications and automotive products. FIG. 2 is a diagram of a relationship between of a reflectance and a wavelength according to Embodiment 1.

Comparative Example 1

[0032] A wide angle application high reflective mirror has a high reflection band in the range of 850 nm to 950 nm, and the band contains a gold film.

[0033] The material of the substrate is a common K9 optical glass.

[0034] Performance comparison is made between the reflective mirrors of Embodiment 1 and Comparative Example 1:

[0035] As shown in FIG. 4 and FIG. 5, the target reflection band of Comparative Example 1 can satisfy application of an incident angle of approximately 0 to 85 degrees. The high reflection band of Comparative Example 1 has a reflectance of greater than 96% with an incident angle ranging from 0 to 80 degrees.

[0036] The lower reflectance increases the loss of an optical path and reduces the signal-to-noise ratio of an optical system. Moreover, exposing the gold film material to the air will make the reflective mirror less resistant to moisture, humidity, and abrasion, and will not meet the needs of harsh environments.

Comparative Example 2

[0037] A wide angle application high reflective mirror has a high reflection band in the range of 850 nm to 950 nm, and the structure thereof includes a plurality of high refractive index film layers and a plurality of low refractive index film layers which are alternately stacked.

[0038] The material of the high refractive index film layer is TiO.sub.2, and the refractive index thereof near 900 nm is 2.25.

[0039] The material of the low refractive index film layer is SiO.sub.2, and the refractive index thereof near 900 nm is 1.48.

[0040] The material of the substrate is a common K9 optical glass.

[0041] Performance comparison is made between the reflective mirrors of Embodiment 1 and Comparative Example 2:

[0042] As shown in FIG. 6 and FIG. 7, in Comparative Example 2, >99% reflectance at the target reflection band can be achieved, but meeting this reflectance can only limit the application angle from 0 to about 50 degrees. As the incident angle increases, the overall shape of the film system shift in the short-wavelength direction, and the reflectance deteriorates significantly in the application range of 50-80 degrees.

[0043] The small range of incident angles limits its application to optical systems with great field of view. Systems based on this reflective mirror cannot be used for occasions of large angle incidence.