Spontaneous emission of a nanoscopic emitter in a strongly scattering disordered medium

TL;DR

This study measures fluorescence lifetimes of nanocrystals in a strongly scattering medium, revealing lifetime fluctuations likely due to local density of states changes, and offers a promising method to explore light localization.

Contribution

It demonstrates a novel experimental approach to investigate spontaneous emission in disordered media and links lifetime fluctuations to local density of states variations.

Findings

Fluorescence lifetimes fluctuate in scattering media

Lengthening of lifetimes attributed to reduced local density of states

Method promising for studying 3D light localization

Abstract

Fluorescence lifetimes of nitrogen-vacancy color centers in individual diamond nanocrystals were measured at the interface between a glass substrate and a strongly scattering medium. Comparison of the results with values recorded from the same nanocrystals at the glass-air interface revealed fluctuations of fluorescence lifetimes in the scattering medium. After discussing a range of possible systematic effects, we attribute the observed lengthening of the lifetimes to the reduction of the local density of states. Our approach is very promising for exploring the strong three-dimensional localization of light directly on the microscopic scale.