# Quantum dot resonant-fluorescence linewidth narrowing and enhanced intensity

## TL;DR

This study demonstrates linewidth narrowing and fluorescence enhancement in quantum dots under resonant excitation with weak non-resonant light, supported by experimental observations and Monte Carlo simulations.

## Contribution

It reveals the mechanisms behind linewidth narrowing and fluorescence enhancement, highlighting the role of charge-carrier loss induced by resonant laser excitation.

## Key findings

- Linewidth decreases with resonant excitation and weak non-resonant light.
- Enhanced resonant fluorescence observed and modeled.
- Charge-carrier loss is key to the phenomena.

## Abstract

We study the processes in a quantum dot and its surrounds under resonant excitation with the addition of weak non-resonant light. We observe a decrease in inhomogeneous emission linewidth, as well as previously observed enhancement of resonant fluorescence (RF). Scanning excitation and detection frequencies, we distinguish between homogeneous and inhomogeneous broadening. Monte Carlo simulations model the enhanced RF only if we include charge-carrier loss from the quantum dot induced by the resonant laser. The cause of the linewidth narrowing is predominantly independent of the enhanced RF.