Free-Carrier Grating Diffraction from Quantum Well Fabry-Perots

摘要

This effort investigated the possibility of replacing the electroabsorption quantum wells with the strong absorption bleaching nonlinearities of high peak-power pulses. Free carrier absorption bleaching was investigated in GaAs epilayers and AlGaAs/GaAs multiple quantum wells for excitation from above bandgap 10 ns pulses. Grating diffraction was also measured. The presence of thermal gratings, due to heating from the high- intensity pump pulse, contributed significantly to the observed diffraction. The lower than expected observed diffraction efficiency was attributed to a reduction in the internal writing efficiency due to the comparable sizes of the diffusion lengths and the grating space.