Nonlinear excitonic optical absorption in GaInAs/InP quantum wells

Abstract

We have studied the saturation of optical absorption in GaInAs/InP quantum wells at room temperature. Using optical excitation from a tunable cw Co:MgF2 laser, we find a saturation intensity of 70 W cm−2 when exciting resonantly at the n=1 heavy-hole exciton, and we deduce values of the nonlinear absorption and refraction coefficients −60 cm W−1 and −0.3 cm2 kW−1, respectively. The saturation intensity in the quantum well is significantly lower than in bulk GaInAs, and also in GaAs quantum wells.