Temporally and spatially resolved plasma emission and stimulated Raman-scattering profiles of water droplets are simultaneously recorded at two selectable wavelengths corresponding to the emission of the resonant and nonresonant sodium, the plasma continuum, the Balmer hydrogen, and the stimulated Raman scattering of water. The propagation speed of the breakout plasma from the droplet shadow face (in the form of a packet) and from the illuminated face is determined. The relative heating of the atoms in the plasma is extracted from the differences between the emission profiles of sodium and hydrogen, which have different electronic energy levels. The plasma response to the multipulse structure of the input laser radiation provides information on plasma shedding and heating for the subsequent pulses and an additional check of the validity of the onedimensional electrohydrodynamic model, which includes a multipulse input.
© 1991 Optical Society of America
Jia-biao Zheng, Wen-Feng Hsieh, Shu-chi Chen, and Richard K. Chang, "Laser-induced breakout and detonation waves in droplets. I. Experiments," J. Opt. Soc. Am. B 8, 319-328 (1991)