Abstract

Absorption of light only becomes irreversible once phase relaxation has occured. On a shorter time-scale, coherent phenomena play a crucial role, and the relative phase of a series of light pulses strongly influences the dynamics even if the pulses do not overlap in time. These experiments are especially interesting in semiconductos which cannot be considered as a simple two-level system but have to be described by the semiconductor Bloch equations [1] to allow for the dominant Coulomb effects. Here we report on recent advances in coherent carrier control [2,3] with pairs of phase- locked 100 fs pulses on low-dimensional semiconductor structures. The dynamics is probed in differential reflection, Faraday rotation, and four wave mixing.

© 1996 Optical Society of America