Digital Library / STP / STP1015-EB / STP18780S

Thresholds Measured With 350-nm Pulses at 25-100 Hz for Bare Polished Crystals of CaF2 and for Silica Sol-gel AR Coatings on Silica Substrates
Staggs, MC
Lawrence Livermore National Laboratory University of California, California

Milam, D
Lawrence Livermore National Laboratory University of California, California

Thomas, IM
Lawrence Livermore National Laboratory University of California, California

Wilder, JG
Lawrence Livermore National Laboratory University of California, California

Pages: 8    Published: Jan 1988

Download this paper for $25 PDF (328K)          View License Agreement
        Click here to download the complete source publication for $77 PDF (14M)

Source: STP1015-EB

Abstract

An XeF laser-damage experiment was used to measure damage thresholds for bare polished crystals of CaF2 and porous silica antireflection coatings on fused silica substrates. Damage was induced by applying 1000 350-nm, 25-ns pulses at repetition rates of 25-100 Hz to small (typically 0.12 × .03 cm) sites on the surfaces of the sample. Eight samples of fluorescence-free CaF2 exhibited both surface and bulk damage at fluences as low as 10 J/cm2. Three samples of UV-grade CaF2 also had surface damage thresholds of 10 J/cm2, and bulk damage was not observed in this material. Thresholds for the porous silica coatings were 17-23 J/cm2.

Keywords:
calcium fluoride, multishot damage testing, porous silica antireflection coatings, ultraviolet laser damage

Paper ID: STP18780S
Committee/Subcommittee: F01.11
DOI: 10.1520/STP18780S
ASTM International is a member of CrossRef.