Transient-grating Studies in GaAs/GaAlAs Multiple Quantum Wells

Abstract

We report degenerate four-wave mixing experiments at room temperature, using a three-beam geometry and sub-picosecond laser to study GaAs/GaAlAs multiple quantum well material. Diffraction efficiencies and grating decay times for two samples of different carrier lifetimes have been measured in the spectral region corresponding to excitonic resonances. The measurements provide values of the nonlinear refractive index per carrier pair (n _eh) deriving from the excitonic saturation, and also the recombination times and diffusion coefficients for the samples.