Morphologies of laser-induced damage in hafnia-silica multilayer mirror and polarizer coatings
Hafnium-silica multilayer mirrors and polarizers were deposited by e-beam evaporation onto BK7 glass substrates. The mirrors and polarizers were coated for operation at 1053 nm at 45{degree} and at Brewster`s angle (56{degree}), respectively. They were tested with a single 3-ns laser pulse. Morphology of the laser-induced damage was characterized by optical and scanning electron microscopy. Four distinct damage morphologies were found: pits, flatbottom pits, scalds, and delaminates. The pits and flat bottom pits (<30{mu}m dia) were detected at lower fluences (as low as 5 J/cm{sup 2}). The pits seemed to result from ejection of nodular defects by causing local enhancement of the electric field. Scalds and delaminates could be observed at higher fluences (above 13 J/cm{sup 2}) and seemed to result from the formation of plasmas on the surface. These damage types often originated at pits and were less than 300 {mu}m diameter; their size increased almost linearly with fluence. Finally, effects of the damage on the beam (reflectivity degradation and phase modulations) were measured.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 461389
- Report Number(s):
- UCRL-JC-124879; CONF-9607145-3; ON: DE97051380; TRN: 97:009896
- Resource Relation:
- Conference: 3. Society of Photo-Optical Instrumentation Engineers international workshop on laser beam and optics characterization, Quebec (Canada), 6-10 Jul 1996; Other Information: PBD: Aug 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Growth of laser-induced damage during repetitive illumination of HfO2-SiO2 multilayer mirror and polarizer coatings
Laser conditioning characterization and damage threshold prediction of hafnia/silica multilayer mirrors by photothermal microscopy