We investigate the coherent dynamics at the band edge of GaAs at low temperatures for carrier densities ranging from 4.3 × 1014 cm−3 to 4.4 × 1017 cm−3 by means of spectrally resolved transient four-wave mixing with 14-fs pulses. At large nonequilibrium carrier densities we observe oscillations with an energy-dependent oscillation period related to interference among continuum states. The experimental findings are compared with a simple model. This comparison delivers a weak energy dependence of dephasing in the initial buildup phase of screening.
© 1996 Optical Society of America
M. U. Wehner, D. Steinbach, M. Wegener, T. Marschner, and W. Stolz, "Spectrally resolved four-wave mixing experiments on bulk GaAs with 14-fs pulses," J. Opt. Soc. Am. B 13, 977-980 (1996)