An optically pumped GaN/AlGaN quantum well intersubband terahertz laser

Abstract

We propose an optically pumped nonpolar GaN/AlGaN quantum well (QW) active region design for terahertz (THz) lasing in the wavelength range of 30 µm ∼ 40 µm and operating at room temperature. The fast longitudinal optical (LO) phonon scattering in GaN/AlGaN QWs is used to depopulate the lower laser state, and more importantly, the large LO phonon energy is utilized to reduce the thermal population of the lasing states at high temperatures. The influences of temperature and pump intensity on gain and electron densities are investigated. Based on our simulations, we predict that with a sufficiently high pump intensity, a room temperature operated THz laser using a nonpolar GaN/AlGaN structure is realizable.

Material growth and device fabrication of terahertz quantum-cascade laser based on bound-to-continuum structure

“…There is a broad range of applications associated with the terahertz (THz) technology. [1,2] But it has historically been characterized by a relative lack of convenient radiation sources and detectors. The THz quantum cascade laser (QCL) is a compact and coherent source in THz region, which is a unipolar device based on inter-subband transitions in the conduction band of a specifically engineered semiconductor heterostructure.…”

Binding energies of impurity states in strained wurtzite GaN/AlxGa1−xN heterojunctions with finitely thick potential barriers

“…In recent years, the physical properties of wurtzite Al-GaN/GaN heterostructures have been widely studied due to their promising applications in devices such as the heterostructure field-effect transistor with high electron mobility, laser device with high frequency, etc. [1][2][3][4][5] A great number of experimental and theoretical studies indicate that there exists a strong built-in electric field (BEF) in nitride heterostructure due to the spontaneous and strain-induced piezoelectric polarization [6][7][8][9] since the lattice mismatch between AlN and GaN and their large piezoelectric coefficients. Bernardini et al [10,11] studied ab initio the spontaneous polarization and piezoelectric constants of the III-V nitrides AlN, GaN, and InN.…”