Time-resolved measurements of elastic scattering and stimulated Raman scattering (SRS) in micrometer-sized water and carbon tetrachloride droplets irradiated with a pulsed, frequency-doubled Nd:YAG laser (pulse width 8 nsec, λ = 532 nm, peak intensity ~1 GW cm-2) are reported. Elastic scattering of light is instantaneous within our measurement error, estimated to be <±3 nsec. On the other hand, the first Stokes shift in water and multiple-order (through ninth-order) Stokes shifts in carbon tetrachloride are delayed from the elastically scattered light by 5–7 nsec. The delay in SRS is apparently a consequence of structure resonances within the droplet, which acts as an optical cavity with relatively high Q. Quasi-periodic peaks in SRS spectra of water droplets are shown to be associated with elastic-scattering structure resonances having the same mode order.
© 1988 Optical Society of America
R. G. Pinnick, A. Biswas, P. Chyălek, R. L. Armstrong, H. Latifi, E. Creegan, V. Srivastava, M. Jarzembski, and G. Fernández, "Stimulated Raman scattering in micrometer-sized droplets: time-resolved measurements," Opt. Lett. 13, 494-496 (1988)