Composition and method of making high-reflection silver mirrors or thin-film optical filters
View Patent ↗An environmentally stable Silver containing mirror or thin-film optical filter having very high reflection values over a large spectral and angular range, and a method for constructing the mirror, or thin-film optical filter, comprising using a substrate that has been exposed to an Argon rich ion stream to prepare the surface. A medium index material is then deposed on the surface with Argon ion bombardment. The Silver is then deposited until it is opaque. A second deposition of the medium index material is next done with the Argon ion bombardment. The coating is then followed with a standard ion assisted deposed optical film to maximize reflection at the desired wavelength and angle of incidence.
1. A method of making a high-reflection mirror or thin-film optical filter comprising:
providing a substrate;
exposing said substrate to an argon rich ion stream;
depositing a first layer of medium index material, or mixture of materials having a combined medium refractive index, on the surface of said substrate with argon ion bombardment to deplete the oxide from said medium index material;
depositing a Silver layer until said Silver layer is maximally reflective;
depositing a second layer of said medium index material, or mixture of materials having a combined medium refractive index, on the surface of said Silver layer with argon ion bombardment to deplete the oxide from said medium index material; and,
depositing one or more optical film layers to maximize reflection at the desired wavelength and angle of incidence.
2. A method according to claim 1 including depositing said one or more optical film layers using an ion assisted procedure.
3. A method according to claim 1 wherein said Silver layer is deposited to a thickness of approximately 2 microns.
4. A method according to claim 1 wherein said first layer of medium index material, or mixture of materials having a combined medium refractive index, and said second layer of said medium index material, or mixture of materials having a combined medium refractive index, are primarily Aluminum Oxide.
5. A method according to claim 4 wherein said first layer of medium index material, or mixture of materials having a combined medium refractive index, and said second layer of said medium index material, or mixture of materials having a combined medium refractive index, are PrAlO3.
6. A method according to claim 1 including cleaning said substrate with an abrasive or chemical cleaning method before applying said first layer of said medium index material, or mixture of materials having a combined medium refractive index.
7. A high-reflection mirror or thin-film optical filter comprising:
a substrate;
a first layer of medium index material, or mixture of materials having a combined medium refractive index, deposited on the surface of said substrate;
said first layer of medium index material, or mixture of materials having a combined medium refractive index, deposited with argon ion bombardment to deplete the oxide from said medium index material;
an opaque Silver layer deposited on the surface of said first layer of medium index material, or mixture of materials having a combined medium refractive index;
a second layer of said medium index material, or mixture of materials having a combined medium refractive index, deposited on the surface of said Silver layer;
said second layer of medium index material, or mixture of materials having a combined medium refractive index, deposited with argon ion bombardment to deplete the oxide from said medium index material; and,
one or more optical film layers deposited on the surface of said second layer of said medium index material, or mixture of materials having a combined medium refractive index.
8. A mirror or thin-film optical filter according to claim 7 including depositing said one or more optical film layers using an ion assisted procedure.
9. A mirror or thin-film optical filter according to claim 7 wherein the material and thickness of said one or more optical film layers is chosen to maximize reflection at the desired wavelength and angle of incidence.
10. A mirror or thin-film optical filter according to claim 7 wherein said Silver layer is deposited to a thickness of approximately 2 microns.
11. A mirror or thin-film optical filter according to claim 7 wherein said first layer of medium index material, or mixture of materials having a combined medium refractive index, and said second layer of said medium index material, or mixture of materials having a combined medium refractive index, are primarily Aluminum Oxide.
12. A mirror or thin-film optical filter according to claim 11 wherein said first layer of medium index material, or mixture of materials having a combined medium refractive index, and said second layer of said medium index material, or mixture of materials having a combined medium refractive index, are PrAlO3.
13. A mirror or thin-film optical filter according to claim 7 wherein said substrate has been cleaned with an abrasive or chemical cleaning method.