As a possible cavity quantum electrodynamical system, unlike III-V quantum dots, Si-NCs are not considered ideal emitters for emission rate enhancement observations (Purcell effect). Here, we report on direct measurements of spontaneous emission rate enhancement of Si-NCs embedded in a whispering-gallery mode resonator at room temperature. Using time-resolved microphotoluminescence experiments, we demonstrate important lifetime reductions (similar to 70%) for Si-NCs coupled to cavity modes with respect to uncoupled ones. Comparing experiments with the theoretical Purcell enhancement in a bad emitter regime, we estimate effective linewidths of similar to 10 meV through which Si-NC emitters are coupled to cavity photons. Finally, our study provides an alternative method for the estimation of subnatural linewidths of quantum dots at room temperature.
Probing the Spontaneous Emission Dynamics in Si-Nanocrystals-Based Microdisk Resonators
Ghulinyan, Mher;Pucker, Georg;
2010-01-01
Abstract
As a possible cavity quantum electrodynamical system, unlike III-V quantum dots, Si-NCs are not considered ideal emitters for emission rate enhancement observations (Purcell effect). Here, we report on direct measurements of spontaneous emission rate enhancement of Si-NCs embedded in a whispering-gallery mode resonator at room temperature. Using time-resolved microphotoluminescence experiments, we demonstrate important lifetime reductions (similar to 70%) for Si-NCs coupled to cavity modes with respect to uncoupled ones. Comparing experiments with the theoretical Purcell enhancement in a bad emitter regime, we estimate effective linewidths of similar to 10 meV through which Si-NC emitters are coupled to cavity photons. Finally, our study provides an alternative method for the estimation of subnatural linewidths of quantum dots at room temperature.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
