Research progress in terahertz quantum-cascade lasers and quantum-well photodetectors

Tan Zhi-Yong^{1, 2}, Wan Wen-Jian¹, Cao Jun-Cheng^{1, 2, †}

Schematic conduction band edge profile of a GaAs/AlGaAs terahertz QWP under zero (above) and finite (below) bias.