Abstract
A pilot study is described in which the resonance of the 10.6-μm CO2 laser radiation with the ν3 vibrational level of the SF6 molecule is used to explore the effect of gas density on the time response of fluorescence. A slow increase of the fluorescent decay time with pressure of pure SF6 is found that is interpreted in terms of a degree of equilibrium between vibrational and translational temperatures. In SF6–air mixtures, however, the increase of air pressure from 0 atm to 1 atm produces a proportional increase of the time constant from milliseconds to seconds in a process in which the vibrational–translational relaxation time is very small compared with the bulk cooling time determined by the thermal diffusivity. The results are compared with previous studies using Q-switched pulse excitation.
© 1972 Optical Society of America
Full Article | PDF ArticleMore Like This
Yoram J. Kaufman, Shlomo Ruschin, and Uri P. Oppenheim
Appl. Opt. 16(5) 1187-1191 (1977)
Cheng-Zhi Pan, R. Bruzzese, S. Solimeno, and R. Velotta
J. Opt. Soc. Am. B 4(4) 452-461 (1987)
Lucinda S. Yuen, James E. Peters, and Robert P. Lucht
Appl. Opt. 36(15) 3271-3277 (1997)