3.8 THz quantum cascade laser grown by metalorganic vapor phase epitaxy

We have demonstrated a quantum cascade laser (QCL) with a generation frequency of about 3.8 THz, grown by metal-organic vapor phase epitaxy. The multilayer heterostructure for QCLs consists of 185 repetitions of an active module containing four GaAs/Al$_{0.15}$Ga$_{0.85}$As quantum wells. The threshold current and threshold voltage of the fabricated QCL were 2.25 kA/cm$^2$ and 19.7 V, respectively. The QCL oscillations were carried out in the multimode regime, and the detection of terahertz radiation continued with an increase in the laser temperature up to 60 K.