Laser-damage susceptibility of nodular defects in dielectric mirror coatings: AFM measurements and electric-field modeling
- University of California, Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
Atomic force microscopy (AFM) and electromagnetic field modeling were used to study the influence of nodular coating defects on laser-induced damage of multilayer dielectric coatings. In studies of HfO[sub 2]/SiO[sub 2] mirrors with 1.06 [mu]m illumination, AFM results showed that nodular defects with high dome heights ([gt]0.6 [mu]m) were most susceptible to laser damage. Crater defects, formed by nodules ejected from the coating prior to illumination, were not damaged when illuminated over the same range of fluences. A finite-difference time-domain electromagnetic modeling code was used to study the influence of 3-D nodule defects on the E-field distribution within the interference coating. The modeling results show that E-field enhancements as large as a factor of 4 can be present at the defects. Crater defects, however, result in minimal enhancement of the E-fields within the coating. These modeling results are consistent with the AFM experimental data, indicating that E-field enhancement is a contributing mechanism in defect-dominated laser damage of optical coatings.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5254318
- Report Number(s):
- CONF-9304144-; CODEN: APCPCS; TRN: 94-005385
- Journal Information:
- AIP Conference Proceedings (American Institute of Physics); (United States), Vol. 288:1; Conference: 2. international conference on laser ablation: mechanisms and applications, Knoxville, TN (United States), 19-22 Apr 1993; ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Laser-damage susceptibility of nodular defects in dielectric mirror coatings: AFM measurements and electric-field modeling
Correlation of damage threshold and surface geometry of nodular defects in HR coatings as determined by in-situ atomic force microscopy
Related Subjects
HAFNIUM OXIDES
PHYSICAL RADIATION EFFECTS
SILICON OXIDES
COATINGS
DEFECTS
DIELECTRIC MATERIALS
ELECTRIC FIELDS
LASER RADIATION
MIRRORS
CHALCOGENIDES
ELECTROMAGNETIC RADIATION
HAFNIUM COMPOUNDS
MATERIALS
OXIDES
OXYGEN COMPOUNDS
RADIATION EFFECTS
RADIATIONS
REFRACTORY METAL COMPOUNDS
SILICON COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360206* - Ceramics
Cermets
& Refractories- Radiation Effects