Efficient excitation of dye molecules for single photon generation

TL;DR

This paper presents a model and experimental validation for efficiently exciting dye molecules to generate single photons, achieving over 99% excitation probability at cryogenic temperatures, advancing practical quantum photon sources.

Contribution

The paper introduces a simple model for excitation efficiency of dye molecules and demonstrates its validity through experiments, showing high photon generation efficiency with modest cooling.

Findings

Maximum excitation probability is 75% at room temperature.

Cooling to liquid nitrogen temperature increases efficiency to over 99%.

Model accurately predicts excitation efficiency in experimental conditions.

Abstract

A reliable photon source is required for many aspects of quantum technology. Organic molecules are attractive for this application because they can have high quantum yield and can be photostable, even at room temperature. To generate a photon with high probability, a laser must excite the molecule efficiently. We develop a simple model for that efficiency and discuss how to optimise it. We demonstrate the validity of our model through experiments on a single dibenzoterrylene (DBT) molecule in an anthracene crystal. We show that the excitation probability cannot exceed 75\% at room temperature, but can increase to over 99\% if the sample is cooled to liquid nitrogen temperature. The possibility of high photon generation efficiency with only modest cooling is a significant step towards a reliable photon source that is simple and practical.