Optimized intervalence band transitions and population inversion patterns in k-space induced by femtosecond infrared pulses

Optimized intervalence band transitions of holes in p-type semiconductors subjected to femtosecond infrared optical fields are considered. The genetic algorithm is used to find minimal energy femtosecond pulses which maximize the transition probability of a heavy-mass hole to either light-mass or split-off band. Inversion of distribution of holes in wave vector k-space induced by such femtosecond pulses is studied. The distribution of coherently excited holes in both light-mass and split-off bands is shown to exhibit characteristic patterns in two-dimensional sections of k-space. The character of the patterns depends on the driving femtosecond pulse shape, energy and valence band properties. Examples of the optimized transitions and inversion patterns are presented for p-type GaAs.