Transition from induced absorption to saturation of intersubband transitions in GaN/AlGaN quantum well structures

In this paper, we show that different GaN heterostructures exhibit distinct nonlinear optical response. The response is studied using spectrally integrated pump-probe technique. The intersubband (ISBT) relaxation dynamics of excited carriers in GaN quantum well(QW) structures and their nonlinearities is essential for possible ultrafast optoelectronic applications based on these transitions.