Absorption and damage thresholds of low defect density hafnia deposited with activated oxygen
Motivation for this work included observations of a correlation between increasing laser damage thresholds and both decreasing nodular-defect density and absorption of coatings. We reduced the nodular-defect densities by a factor of over 4x in hafnia coatings deposited by reactive e-beam evaporation from a Hf target source. In order to increase the metal oxidation kinetics at the coated surface, Hf was e-beam deposited reactively with oxygen activated by a {mu}-wave discharge. The effect of using activated oxygen during the evaporation of a hafnia target source was also evaluated. A series of hafnia layers were made with various conditions; we alternated between two {mu}-wave configurations, hafnium and hafnia targets and two reactive oxygen pressures. Laser damage thresholds (1064 nm -10 ns pulses), absorption (at 511 nm) and nodular-defect densities from these coatings are reported. The damage threshold correlated inversely with the coating absorption.
- Research Organization:
- Lawrence Livermore National Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 10157669
- Report Number(s):
- UCRL-JC-111458; CONF-9210356-1; ON: DE93013853
- Resource Relation:
- Conference: Laser-induced damage in optical materials,Boulder, CO (United States),28-30 Oct 1992; Other Information: PBD: Oct 1992
- Country of Publication:
- United States
- Language:
- English
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