Polariton amplification in a multiple-quantum-well resonant photonic crystal

TL;DR

This paper predicts that in a multiple-quantum-well resonant photonic crystal, four-wave mixing can cause phase-conjugate oscillation instability, resulting in significant amplification of a weak probe pulse under specific conditions.

Contribution

It introduces a microscopic many-particle theory to analyze polariton amplification in Bragg-spaced quantum wells, revealing instability mechanisms for probe pulse amplification.

Findings

Four-wave mixing induces energy transfer from pump to probe.

Phase-conjugate oscillation causes instability leading to amplification.

Amplification of weak probe pulses can be achieved under certain excitation conditions.

Abstract

Based on a microscopic many-particle theory we study the amplification of polaritons in a multiple-quantum-well resonant photonic crystal. For the Bragg-spaced multiple quantum wells under investigation we predict that in a typical pump-probe setup four-wave mixing processes can lead to an unstable energy transfer from the pump into the probe and the background-free four-wave mixing directions. We find that under certain excitation conditions this phase-conjugate oscillation induced instability can lead to a large amplification of the weak probe pulse.