Short-period InGaAs/AlInAs THz quantum cascade lasers in thin double metal cavities operating up to 188 K

We present a two-well terahertz (THz) quantum cascade laser designed for high-temperature operation based on the InGaAs/AlInAs material system. The lighter effective mass and higher energy barriers increase the gain at high temperatures (T > 150 K). When processed in copper-based double metal waveguides, the devices show laser action up to a maximum operating temperature of 188 K with a maximum current density of 1.4 kA/cm2. The low Joule heating due to reduced active region thickness and low electrical bias allows operation at 10% duty cycle up to a temperature of 170 K.