Structural design of active region in resonant-phonon Terahertz QCL

The transmission coefficients and wave function of electron in single period of resonant phonon (RP) Terahertz Quantum Cascade Laser active region were calculated with bias by Airy function substitution and transmission matrix methods, distribution of the electron wave function and relationship curve of quasi-bound level (Subband) and bias were obtained. Based on simulation results, a RP Terahertz Quantum Cascade Laser active region structure was designed. The simulation results showed that THz lasing appeared when bias of SP structure was 51.67mV. The wave function corresponding with E₂ and E₁ energy level could overlap at lasing region and related lasing wave which wavelength was 90.0μm and frequency was 3.2 THz was within THz frequency. At population inversion region, the transition energy from E₁ to E₀ was 38.62meV, which was approximate to the energy of longitudinal optical (LO) phonon. It was good for achieving large population inversions.