Abstract

When an ultra-short and intense laser field propagates inside a dielectric medium, it induces a strong polarization field and, if the intensity is high enough, it produces a high density of electrons and holes. In this paper, we report on an experiment based on a new phase-sensitive technique [1,2] which allows the direct visualization of the polarization and the excitation density with a resolution of 120 femtosecond in time and 5 μm in space. To our knowledge, the very first relaxation events, concerning the photogenerated carriers in the conduction band, remain an unexplored domain in wide band-gap insulators.

© 1994 Optical Society of America