Terahertz generation in gallium nitride quantum wells

Terahertz emission spectroscopy was used to characterize InGaN/GaN and GaN/AlGaN quantum well structures grown along the polar $c$-axis and investigate the role of the built-in electrostatic fields in the generation of terahertz radiation. The fields were first calculated using a self-consistent $k ^{*} p$solver and compared to the magnitudes of the transient electric fields generated when the structures were excited in reflection geometry with femtosecond laser pulses.