SYMPOSIA PAPER Published: 01 January 1985

Defect Damage Precursors in Visible-Wavelength Mirrors


Video monitoring of pulsed visible-wavelength mirror damage has led to observation of illuminated defects as a precursor to observable microscopic damage. The blue-green illuminating radiation is produced in individual 0.5 μs pulses by a tunable flashlamp-pumped dye laser. The laser light is focused on multilayer dielectric or metal surfaces in an ⋍ 0.5 mm (D − 1/32) spot with a reproducible, flat-top spatial profile. An area slightly larger than the focal spot is viewed with a close-focusing Questar telescope equipped with a highly sensitive video camera. Typically, at nondamaging energy densities, defect sites within the focal spot area appear to be brightly illuminated at the laser wavelength. In dielectric mirrors, the illumination pattern depends on the laser wavelength, suggesting a sensitivity to defect position with respect to the standing wave field. At higher energy densities, laser damage originates only at certain defect sites, while other areas fail to damage even after many laser pulses. This paper presents results of an experimental characterization of the described phenomena.

Author Information

Marrs, CD
Porteus, JO
Palmer, JR
Price: $25.00
Contact Sales
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Developed by Committee: E13
Pages: 378–384
DOI: 10.1520/STP28992S
ISBN-EB: 978-0-8031-4956-4
ISBN-13: 978-0-8031-0930-8