Thin THz QCL active regions for improved continuous-wave operating temperature

We compare the performance of 10 and 5 μm thick metal–metal waveguide terahertz quantum-cascade laser ridges operating around 2.7 THz based on a 4-well phonon depopulation active region design. Thanks to reduced heat dissipation lower thermal resistance, material shows an 18 K increase in continuous wave temperature compared material, despite maximum pulsed-mode larger input power density. A 129 is achieved using 15 wide ridge waveguide, which lased up 155 pulsed mode. The use thin regions likely become increasingly important address increasing density emerging 2- 3-well designs that show highest temperatures.