Stimulated scattering and lasing of intersubband cavity polaritons

TL;DR

This paper develops a microscopic theory for intersubband polariton scattering in microcavities, revealing conditions for ultralow threshold lasing via stimulated phonon emission in semiconductor systems.

Contribution

It introduces a novel microscopic model for polariton scattering induced by optical phonons, accounting for deviations from bosonic behavior at high densities, and predicts conditions for lasing without inversion.

Findings

Final-state stimulation is possible for intersubband polaritons.

Ultralow threshold lasing can be achieved without population inversion.

Predicted regimes for quantum degeneracy in GaAs systems.

Abstract

We present a microscopic theory describing the stimulated scattering of intersubband polariton excitations in a microcavity-embedded two-dimensional electron gas. In particular, we consider the polariton scattering induced by the spontaneous emission of optical phonons. Our theory demonstrates the possibility of final-state stimulation for the scattering of such composite excitations, accounting for the deviations from perfect bosonicity occurring at high excitation densities. By using realistic parameters for a GaAs semiconductor system, we predict how to achieve a quantum degenerate regime, leading to ultralow threshold lasing without population inversion.