Single-pulse pump-probe measurement of optical nonlinear properties in GaAs/AlGaAs multiple quantum wells

摘要

Single-pulse ps-pump and ns-probe nonlinear transmission measurements provide carrier-density-dependent optical nonlinear spectra in GaAs/AlGaAs multiple quantum wells grown by metalorganic chemical vapor deposition. The use of the ps pump eliminates the need to know carrier lifetime to determine carrier density. The saturation behavior of changes in absorption coefficient and refractive index are modeled by a simple saturation equation to obtain saturation carrier density. The saturation spectra for different well thicknesses are obtained. The minimum saturation carrier density appears around 150 /spl Aring/.