Comparison between 355 nm and 1064 nm damage of high grade dielectric mirror coatings

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:552067

Bodemann, A; Kaiser, N ^[1]

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1. Fraunhofer Institut fuer Angewandte Optik und Feinmechanik, Jena (Germany); and others

Advanced reactive e-beam evaporation process was used to deposit HfO{sub 2}/SiO{sub 2} HR coatings for 355 nm high power laser applications. Atomic force microscopy studies and Nomarski microscopy have shown that the defect density of these coatings is extremely low exhibiting nearly no nodular defects known for an increased susceptibility to laser damage in the IR spectral region. Standard damage testing (conditioned and unconditioned) was conducted at LLNL at 355 nm (3 ns) for normal (0{degrees}) and nonnormal-incident designs (45{degrees}). Damage thresholds between 5 J/cm{sup 2} and 8 J/cm{sup 2} were obtained. No significant conditioning effect could be demonstrated. The same evaporation technique was used to manufacture normal incident HfO{sub 2}/SiO{sub 2} HR coatings for 1064 nm wavelength from 2 different types of evaporant grade HfO{sub 2} as well as from a Hf metal source. Damage test results, as well as defect concentrations and conditioning effect, were compared to the 355 nm samples. Moreover, care was taken on the detection of the origin of damage at fluences near the damage thresholds.

• Research Organization: International Society for Optical Engineering, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 552067
• Report Number(s): CONF-9510106--Vol.2714
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CRYSTAL DEFECTS
DAMAGE
HAFNIUM OXIDES
LASER RADIATION
MIRRORS
PHYSICAL VAPOR DEPOSITION
REFLECTIVE COATINGS
SILICON OXIDES