Molecular Vibrations in Liquids: Direct Measurement of the Molecular Dephasing Time; Determination of the Shape of Picosecond Light Pulses

Abstract

Molecular vibrations are coherently excited by an intense light pulse of duration $t_p$. The rise and decay of the vibrational amplitude is measured with delayed pulses of the same time dependence. The molecular dephasing time $\tau$ is obtained when $\tau \gtrsim t_p$, while the shape of the light pulse is found for $\tau \ll t_p$.