抄録
Terahertz quantum cascade lasers (THz QCLs) are semiconductor-based promising high output power THz
sources with narrow bandwidth and wide operation frequency. Here we report the progress on high-power
THz QCLs based on optimization of the active region simulated using the non-equilibrium Green’s
function (NEGF) method. The simulations reveal a horizontal parasitic carrier leakage channel via high
energy states in the neighboring period. Through tuning these levels by modifying the Al1-xGaxAs barriers
and wells, the carrier population at these parasitic high energy levels is reduced and the leakage current
significantly is suppressed, resulting in higher output power. Peak power of > 400 mW and average power
> 0.4 mW with 3.8 THz emission at 20 K are routinely obtained. Moreover, we developed a compact
THz source unit with the QCL device installed inside a 77 K Dewar condenser.
