Simulation of saturation and relaxation of intersubband absorption in doped quantum wells

Abstract

We have simulated the saturation and relaxation of intersubband absorption in doped GaAs quantum wells, in which radiation excites electrons between the ground and higher subbands. Screened longitudinal optic (LO) phonon, hot LO phonon, acoustic phonon, intrasubband scattering, conduction-band nonparabolicity, and intervalley scattering were included in our simulation. We find that the change in absorption relaxes with a time constant of about 5 ps after pulsed excitation. Under continuous excitation the absorption saturates as a nearly homogeneously broadened system.