Terahertz quantum cascade lasers

Abstract

We report our successful development of THz quantum cascade lasers with two unique features. The intersubband gain medium is based on resonant optical phonon scattering to depopulate the lower lasing level, and the THz mode confinement is achieved using a metal-semiconductor-metal waveguide. To date, lasing has been achieved at wavelengths longer than 100 mW and above liquid nitrogen temperature. Maximum peak power levels exceed 10 mW and more than 4 mW of power is still available at liquid nitrogen temperature.