Accession Number : ADA309634

Title :   Experimental Investigation of Ultrashort Pulse Laser-Induced Breakdown Thresholds in Aqueous Media,

Corporate Author : ARMSTRONG LAB BROOKS AFB TX OCCUPATIONAL AND ENVIRONMENTAL HEALTH DIRECTORATE

Personal Author(s) : Hammer, Daniel X. ; Thomas, Robert J. ; Noojin, Gary D. ; Rockwell, Benjamin A. ; Kennedy, Paul K.

PDF Url : ADA309634

Report Date : APR 1996

Pagination or Media Count : 11

Abstract : Laser induced breakdown (LIB) thresholds are determined for pulse durations of 2.4 PS, 400 fs, and 100 fs at 580 nm in high purity water, saline and tap water. The dependence of LIB irradiance thresholds on pulse duration, optical wavelength, and focal volume is examined, and the experimental data obtained is compared with a theoretical model. The slopes of the probability curves calculated are compared with mechanisms for LIB, namely avalanche ionization, multiphoton initiated avalanche ionization, and multiphoton ionization. Lastly, the dependence of the peak breakdown electric field on pulse duration and focal volume is empirically determined and compared with previous work.

Descriptors :   *BREAKDOWN(ELECTRONIC THRESHOLD), *LASER TARGET INTERACTIONS, REPRINTS, OPTICAL PROPERTIES, EXPERIMENTAL DATA, HIGH RATE, WATER, PULSE RATE, PURITY, IONIZATION, PHOTOIONIZATION, AVALANCHE EFFECT(ELECTRONICS).

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE