Theory of an excitonic THz laser with two-photon excitation

TL;DR

This paper theoretically explores a THz laser system using a quantum well inside coupled microcavities, demonstrating that two-photon excitation induces nonlinear effects like bistability and hysteresis in the THz emission.

Contribution

It introduces a novel theoretical model for a THz laser based on two-photon excitation of excitons in a coupled microcavity system, highlighting nonlinear phenomena.

Findings

Two-photon excitation induces bistability in THz output.

Nonlinearity leads to hysteresis effects.

System stability depends on microcavity parameters.

Abstract

We consider theoretically THz lasing in a system consisting of a quantum well placed inside an optical microcavity and a THz cavity in the regime of two-photon excitation of 2p dark exciton states. The stability of the system with varying parameters of the microcavity under coherent pumping is studied. We show that the nonlinearity provided by two photon absorption can give rise to bistability and hysteresis in the THz output.