The response of multilayer dielectric coatings to low fluence uv light exposure
An experiment was conducted to determine the damaging effects of low fluence, ultraviolet light exposure to the performance of various 1-..mu..m multilayer dielectric high-reflector coatings. A multiline, cw, 1.15 ..mu..m He Ne laser was used to measure variations in coating reflectivity as damaging uv light was applied. The coated substrate under test formed one end of the He Ne laser resonator. Coating reflectivity loss was determined by relating changes in He Ne laser circulating power to changes produced by known insertion losses. Coating reflectivity degradation was measured as a function of uv exposure duration and uv fluence for uv wavelengths of 248 and 351 nm. The reflectivity of all dielectric coatings measured was found to degrade in response to 65-min. exposures to 248- or 351-nm light. Measured coating reflectivity loss varied from 0.11% for ZrO/sub 2//SiO/sub 2/ to 1.05% for TiO/sub 2//SiO/sub 2//HfO/sub 2/. Significant reflectivity recovery after termination of 351-nm irradiation was observed, whereas reflectivity degradation induced by 248-nm irradiation was permanent. 6 refs., 9 figs., 2 tabs.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 6415814
- Report Number(s):
- LA-UR-89-269; CONF-8810296-2; ON: DE89006518
- Resource Relation:
- Conference: Boulder damage symposium, Boulder, CO, USA, 26 Oct 1988; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HAFNIUM OXIDES
RADIATION EFFECTS
SILICON OXIDES
TITANIUM OXIDES
ZIRCONIUM OXIDES
DAMAGE
DIELECTRIC MATERIALS
LAYERS
LOSSES
REFLECTIVE COATINGS
REFLECTIVITY
ULTRAVIOLET RADIATION
CHALCOGENIDES
COATINGS
ELECTROMAGNETIC RADIATION
HAFNIUM COMPOUNDS
MATERIALS
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RADIATIONS
REFRACTORY METAL COMPOUNDS
SILICON COMPOUNDS
SURFACE PROPERTIES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
360206* - Ceramics
Cermets
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360204 - Ceramics
Cermets
& Refractories- Physical Properties