SEDL / STP / STP1028-EB / STP18572S

Long-Range Pulselength Scaling of 351 nm Laser Damage Thresholds

Foltyn, SR
Los Alamos National Laboratory, Los Alamos, NM

Jolin, LJ
Los Alamos National Laboratory, Los Alamos, NM

Pages: 8    Published: Jan 1988

Download this paper for $25 PDF (216K)          View License Agreement
Abstract

In a series of experiments incorporating 351-nm pulselengths of 9, 26, 54, and 625 ns, it was found that laser damage thresholds increased as (pulselength)^X, and that the exponent averaged 0.36 and ranged, for different samples, from 0.23 to 0.48. Similar results were obtained when only catastrophic damage was considered. Samples included Al²O³/SiO² in both AR and HR multilayers, HR's of Sc²O³/SiO² and HfO²/SiO², and an Al-on-pyrex mirror; 9-ns thresholds were between 0.2-5.6 J/cm².

When these data were compared with a wide range of other results — for wavelengths from 0.25 to 10.6 μm and pulselengths down to 4 ps — a remarkably consistent picture emerged. Damage thresholds, on average, increase approximately as the cube-root of pulselength from picoseconds to nearly a microsecond, and do so regardless of wavelength or material under test.