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 cm2 when exciting resonantly at the n=1 heavy‐hole exciton, and we deduce values of the nonlinear absorption and refraction coefficients −60 cm W1 and −0.3 cm2 kW1, respectively. The saturation intensity in the quantum well is significantly lower than in bulk GaInAs, and also in GaAs quantum wells.