NONLINEAR ABSORPTION IN (CD,ZN)SE ZNSE SINGLE QUANTUM-WELLS/

Room-temperature measurement of nonlinear transmission in (Cd,Zn)Se/Zn Se single quantum wells is reported. Changes in absorption near the ba nd edge due to optically excited carriers were measured for two sample s with different well widths as a function of wavelength and intensity . The change in absorption occurred at the n = 1 and n = 2 heavy-hole excitons, as well as in the continuum states above the band edge. The peak values for change in absorption are -7000 cm-1 at 10 kW/cm2 for t he narrow well and -8000 cm-1 at 50 kW/cm2 for the wide well. Change i n refractive index was calculated from the absorption results. Saturat ion intensities for the excitonic absorption were 13.3 kW/cm2 for the 7.5 nm well and 2.7 kW/cm2 for the 15 nm well. The data show spectra a nd carrier densities that are consistent with phase-space filling as t he predominant mechanism for absorption change, in agreement with low- temperature results.