Terahertz Lasing in Ensemble of Asymmetric Quantum Dots

Abstract

We propose a scheme of terahertz laser based on an ensemble of asymmetric quantum dots dressed by an intense electromagnetic field. THz emission originates from the transitions at Rabi energy between the neighboring dressed states. For the amplification of the lasing mode, high-Q photonic crystal cavity tuned to terahertz range can be employed. Within the mean field approximation, the system is described by Maxwell–Bloch type equations, which account for inhomogeneous broadening and decoherence processes. The conditions for the onset of the lasing are determined, and emission intensity and quantum efficiency are obtained by numerical solution of the Langevin type stochastic equations, describing the generation of THz pulses. The energy gap between dressed levels is determined by the driving field intensity that implies the ability of flexible control over lasing parameters.