Polarization Dependent Intra-Band Dynamics in Semiconductor Optical Amplifiers

The polarization dependence of gain dynamics in a bulk semiconductor optical amplifier has been investigated using a 2.5 ps pump-probe set-up in a counter-propagation configuration. A theoretical model based on the carrier density rate equation has been developed to simulate the experiment. Comparison of experimental and computational results highlights the dependence of the intra-band dynamics on both the energy of the injected pump pulse and the polarization orientation of the pump and probe signals. The power dependence of the saturation energy and gain compression factor are extracted and seen to be a function of polarization.