Picosecond Free Electron Laser Studies Recombination in Insb and Inassb Systems

Pump-probe experiments have been performed at room temperature in undoped bulk InSb, near and above the fundamental absorption edge at 180 meV using a far-infrared free electron laser. Significant bleaching was seen near the excitation frequency, with recovery times in the range 0.2-5 ns which were found to be strongly dependent on the pump photon energy, The scattering is dominated by Auger processes, which have rates following quadratic or linear carrier density dependence in low excitation and highly degenerate regimes respectively, The coefficients for Auger recombination in InSb at room temperature were found to be 1.1+/-0.5x10(-26) cm(6)s(-1) and 4.0+/-0.5x10(-9) cm(3)s(-1) in these two regimes, A preliminary bleaching experiment on an undoped strained layer superlattice sample of InAs/InAs0.61Sb0.39 is abo reported, which demonstrates strong inhibition of the recombination process.