Linewidth broadening of a quantum dot coupled to an off-resonant cavity

TL;DR

This paper investigates how off-resonant coupling affects linewidth broadening in a quantum dot-cavity system, revealing additional incoherent interactions not predicted by simple models.

Contribution

It demonstrates experimentally that the quantum dot linewidth is significantly broadened due to incoherent coupling with the cavity, beyond theoretical expectations.

Findings

Quantum dot linewidth broadening observed experimentally.

Incoherent coupling between quantum dot and cavity identified.

Linewidth broadening exceeds theoretical estimates.

Abstract

We study the coupling between a photonic crystal cavity and an off-resonant quantum dot under resonant excitation of the cavity or the quantum dot. Linewidths of the quantum dot and the cavity as a function of the excitation laser power are measured. We show that the linewidth of the quantum dot, measured by observing the cavity emission, is significantly broadened compared to the theoretical estimate. This indicates additional incoherent coupling between the quantum dot and the cavity.