Speaker
Description
We present our recent results on the impact of intersubband absorption in the valence band on the performance of interband cascade lasers (ICLs). We observe a clear performance dependence on the thickness and composition of the Ga$_{1-x}$In$_x$Sb hole-quantum well (QW), reflecting in the characteristic temperature $T_\mathrm{0}$ as well as the threshold current density $J_\mathrm{th}$. By careful design of the active W-QW the intersubband absorption in the valence band can be tailored and even completely avoided, allowing us to enhance ICL performance outside of the sweet spot 3-4 μm region, paving the way towards higher cw operating temperatures and output powers.