Nonexponential decay of spontaneous emission from an ensemble of molecules in photonic crystals

R. A. L. Vallée, K. Baert, B. Kolaric, M. Van der Auweraer, and K. Clays

Phys. Rev. B 76, 045113 – Published 19 July 2007

Abstract

Photonic crystals (PCs) with relatively low dielectric contrast (i.e., with pseudogaps) have significant influence on the fluorescence decay of internal emitters. Fluorescence decays of ensembles of dye molecules measured at different positions in the PCs exhibit a nonexponential behavior, which is best fitted by a continuous distribution of decay rates. The most frequent decay rates of these distributions are smaller and their widths are narrower in a PC with a pseudogap acting in the emission range of the emitters than in a PC having the pseudogap out of this range. These experimental results have been well accounted for by calculations of the local density of states and rate constant for spontaneous emission.