Abstract

The elementary excitations of semiconductors are governed by quantum statistics and Coulomb correlation. Both the amplitude and the phase of their nonlinear optical polarization displays a complex temporal behavior. This was experimentally demonstrated by the observation of nonlinear dynamics of the instantaneous-frequency of coherent wave mixing resonant with excitons.¹ However, the continuum-states, well above the band gap, are much more difficult to study because of the ultrafast relaxation of electrons and holes (e–h).^2,3 In this paper we address for the first time the question of the phase dynamics in the continuum of states of quasi-free e–h.

© 1994 Optical Society of America