Coated laser mirror and method of coating

• US 4,444,467 A
• Filed: 08/10/1981
• Issued: 04/24/1984
• Est. Priority Date: 08/10/1981
• Status: Expired due to Fees

• Current Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Shuskus, Alexander J., Cowher, Melvyn E.
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Gallivan, Richard F.
• Application Number:
  US06/291,851
• Time in Patent Office: 988 Days
• Field of Search: 350/310, 427/39, 427/140, 427/142, 427/162, 427/166, 427/167
• US Class Current: 359/846
• CPC Class Codes: C03C 17/09 by deposition from the vapour phase
• CPC Class Codes: C03C 17/22 with other inorganic material C03C17/34, C03C17/44 take precedence
• CPC Class Codes: C03C 2217/268 Other specific metals
• CPC Class Codes: C03C 2217/282 Carbides, silicides
• CPC Class Codes: C03C 2217/29 Mixtures
• CPC Class Codes: C03C 2218/153 by plasma-enhanced cvd
• CPC Class Codes: G02B 5/08 Mirrors vehicle mirrors involving special optical features B60R1/08
• CPC Class Codes: G02B 7/182 for mirrors
• CPC Class Codes: H01S 3/08059 Constructional details of the reflector, e.g. shape mirrors in general G02B5/08; mountings for mirrors G02B7/18
• CPC Class Codes: Y10S 359/90 Methods

Abstract

A method of applying an intermediate bond coat on a laser mirror substrate is described comprising surface polishing the mirror substrate followed by depositing a layer of amorphous silicon, amorphous germanium, or mixtures thereof on the mirror surface, and polishing the thus coated mirror surface to a substantially void-free surface finish. Laser mirror substrates such as graphite fiber reinforced glass, molybdenum and silicon carbide coated by such process are also described.

Claims

1. A laser mirror substrate suitable for subsequent deposition of a laser radiation reflecting outer layer comprising a laser mirror substrate coated with an intermediate bonding layer of plasma enhanced chemical vapor deposited amorphous silicon, amorphous germanium, or mixtures thereof.

2. The article of claim 1 wherein the mirror substrate comprises graphite fiber reinforced glass, silicon carbide or molybdenum.

3. The article of claim 1 wherein the intermediate coating is amorphous silicon.

4. The article of claims 1, 2 or 3 wherein the intermediate coating is overcoated with a laser radiation reflecting outer layer.

5. The mirror of claim 3 wherein the coating is at least 15 microns thick.

6. A method of coating a laser mirror substrate with an intermediate bonding layer comprising surface polishing the mirror surface, baking the polished mirror surface to remove impurities, depositing a layer of amorphous silicon, amorphous germanium, or mixtures thereof on the mirror surface by plasma enhanced chemical vapor deposition, and polishing the coated mirror to a substantially void-free, highly polished surface finish.

7. The mirror of claim 6 wherein after polishing, the surface has a surface finish of about 10 to about 15 Å

rms.

8. The method of claim 6 wherein the coating is at least 15 microns thick.

9. The method of claim 6 wherein after polishing, a laser radiation reflecting outer layer is deposited on the substantially void-free surface finish.

10. The method of claim 6 wherein the mirror substrate comprises graphite fiber reinforced glass, silicon carbide or molybdenum.

11. The method of claim 6 wherein the intermediate coating is amorphous silicon.