Abstract

THz quantum cascade lasers (QCLs) [1,2] are promising high output power semiconductor THz sources to over Watt order peak power [3] with narrow bandwidth. It is still quite limited for the THz applications caused by the large cryogenic system and low duty cycle with low output power at high operation temperature. Output power is one of the most critical parameters for real applications. We demonstrated a 77 K liquid nitrogen Dewar condenser as a compromised compact portable THz source unit with our fabricated QCLs. They showed a stable few ten mW peak power with sub mW average power operation. Analysis the temperature performance of structures by Non-Equilibrium Green’s Function (NEGF) method are discussed. The improvement of the active region and waveguide fabrication will also be discussed for high output power operation in order to exhibit the best performance of the compact 77 K Dewar system.

© 2017 Japan Society of Applied Physics, Optical Society of America