Design for Stable Lasing of an Indirect Injection THz Quantum Cascade Laser Operating at Less Than 2 THz

Abstract

Abstract:In order to realize high temperature lasing of low frequency (< 2 THz) terahertz quantum cascade lasers (THz QCLs), selective carrier injection into an upper lasing level using an indirect injection (II) scheme is an effective method for inducing population inversion. The II scheme is realized with a four-level system. However, a three-level system that operates at low applied bias voltages causes additional lasing at higher frequencies (4～5 THz). By detuning the wave functions at the three lasing levels operating at low bias voltages, we were able to operate an II scheme THz QCL at a single stable frequency. Utilizing the higher injection selectivity, achieved through an indirect scattering-assisted injection process combined with diagonal emission, we were able to demonstrate stable operation of an AlGaAs/GaAs QCL operating at 1.89 THz at temperatures up to 160 K.

Design and simulation analysis of THz wave parabolic antenna with beam deflection

“…THz wave technology is considered to have great application prospects and application value in the aforementioned fields. From the practical engineering applications point of view, THz wave technology based on electronics also has a wide application foundation and market, including the THz wave quantum cascade laser (QCL) technology, 4 backward wave oscillator (BWO) technology. 5 In the THz wave technology based on electronics, the most feasible and easiest to implement is the technique of doubling the microwave or millimeter wave frequency to THz wave.…”