Observation of the Transient Expansion of Heated Surfaces by Picosecond Photothermal Defiection Spectroscopy

Abstract

Recently there has been a considerable amount of work centered on the problem of understanding lattice thermalization of optically excited carriers on the picosecond time scale. A necessary consequence of thermalization of carriers with the lattice is the subsequent lattice expansion. This expansion leads to a propagating elastic stress wave which results in motion of the free surface. In the experiments reported here the technique of photothermal deflection1 has been extended for the first time to the picosecond time domain in order to resolve this surface motion. © 1988 Optical Society of America