Femtosecond-pump, continuum-probe nonlinear absorption in GaAs

Abstract

We present calculations of femtosecond-pump, continuum-probe nonlinear absorption in GaAs, including effects of electrons and heavy, light, and split-off holes. To account for hole-band nonparabolicity and anisotropy, a 30×30 k⋅p Hamiltonian is diagonalized. Carrier dynamics are determined using an ensemble Monte Carlo method. Differential transmission spectra are obtained from the carrier distributions and directly compared with experiments. Our results show that pump–continuum-probe experiments provide the first direct evidence for a redistribution of holes on a femtosecond scale.