WAVELENGTH AND TIME EVOLUTION OF MULTIPLE STIMULATED RAMAN SPECTRA IN CCl4CCl_{4} EXCITED BY AN INTENSE PICOSECOND LASER PULSE

Author Institution: Section Biology, Institut de Radium; Laboratoire de Photosynthese, GIF; P.N. Lebedev Physical Institute, USSRBy focussing a giant laser pulse, delivered by a mode-locked Nd-YAG laser, Into $CCl_{4}$, under specified conditions, a discrete train of stimulated Raman bands was observed. On the anti-Stokes side for instance, using a multichannel spectroscopy method, over 30 bands of very high intensity were recorded, ranging from 1.06 $\mu m$ to below 400 nm. Under the conditions of the experiments, no continuum was detected between the bands. The time evolutions of the various bands were simultaneously examined, using a high speed deflection camera. The following features were observed: 1) the durations of the stimulated Raman bands are always less than that of the excitation laser pulse (either $1.06\mu m$ or 532 nm), 2) the durations of the individual, stimulated Raman bands decrease steadily, as the bands are more distant from the excitation line, 3) the durations of the bands which are far away from the excitation line are below the time resolution capability of the camera used, i.e., $\sim$6 ps