Defect-damage-resistant copper mirrors
Abstract
The calculated threshold for 10.6 micrometer laser induced melting of intrinsic crystalline copper is in excellent agreement with the latest experimental value when the 100 nsec pulse shape and temperature dependent material properties are properly modeled. Melt thresholds of diamond turned copper mirrors recently produced and tested are very nearly intrinsic. However, laser induced pitting related to surface defects often causes failure at a considerably lower level. A well defined inverse relationship between the thresholds for laser induced slip and melting provides a good indication of surface disorder on polished, as well as diamond turned mirrors. Thermal modeling indicates that the premature melting can be avoided by improving the thermal conductivity of the substrate.
- Publication:
-
Laser Induced Damage in Optical Materials
- Pub Date:
- July 1980
- Bibcode:
- 1980nlid.rept..175P
- Keywords:
-
- Copper;
- Mathematical Models;
- Mirrors;
- Pulsed Lasers;
- Silicon Carbides;
- Surface Defects;
- Electropolishing;
- Metal Vapors;
- Substrates;
- Surface Finishing;
- Thermal Diffusivity;
- Vapor Deposition;
- Lasers and Masers