Dynamical calculation of third harmonic generation in a semiconductor quantum well

TL;DR

This paper develops a dynamic model to study third harmonic generation in semiconductor quantum wells, revealing how excitation frequency influences the nonlinear intensity dependence due to carrier saturation effects.

Contribution

It introduces a comprehensive model combining carrier dynamics with light field evolution, specifically applied to third harmonic generation in quantum wells within photonic structures.

Findings

Off-resonant pulses exhibit cubic intensity dependence.

Resonant pulses show reduced exponent due to saturation.

The model enhances understanding of nonlinear carrier-light interactions.

Abstract

Non-linear phenomena in optically excited semiconductor structures are of high interest. We here develop a model capable of studying the dynamics of the photoexcited carriers, including Coulomb interaction on a Hartree-Fock level, on the same footing as the dynamics of the light field impinging on an arbitrary photonic structure. Applying this method to calculate the third harmonic generation in a semiconductor quantum well embedded in a Bragg mirror structure, we find that the power-law exponent of the intensity dependence of the third harmonic generation depends on the frequency of the exciting pulse. Off-resonant pulses follow the expected cubic dependence, while the exponent is smaller for resonant pulses due to saturation effects in the induced carrier density. Our study provides a detailed understanding of the carrier and light field dynamics during non-linear processes.