Temperature Dependence of Laser Induced Breakdown
Final rept. 24-27 Jan 1994
ARMSTRONG LAB BROOKS AFB TX OCCUPATIONAL AND ENVIRONMENTAL HEALTH DIRECTORATE
Pagination or Media Count:
The physical properties of laser-induced optical breakdown LIB in highly transparent, dispersive media, like that found in the eye, are of great interest to the ophthalmic community. We examined the temperature dependent characteristics of LIB thresholds in media with a temperature range of 20 deg C to 80 deg C using nanosecond, picosecond, and femtosecond pulses produced in the visible and near infrared spectral regions. Media used for these studies included high purity water, tap water, physiological 0.9 saline solution, and bovine vitreous. 10ns pulses at 532 nm and 60 ps and 90 fs pulses at 580 nm were focused into a sample to produce LIB. Probit analysis was used to determine the 50 probability threshold value ED50 as the temperature of the media was varied. Additional data was obtained by keeping pulse energy constant and varying temperature. ED50 values for LIB showed no consistent dependence on the temperature of the medium. The theory of the temperature dependence of LIB and experimental observations for all pulse durations and their implications for retinal damage are discussed. Laser Induced Breakdown, Temperature dependence, Threshold valve, Nanosecond, Picosecond, Femtosecond, laser pulses.
- Anatomy and Physiology
- Medicine and Medical Research
- Lasers and Masers