Emission Redistribution from a Quantum Dot-Bowtie Nanoantenna

We present a combined experimental and simulation study of a single self-assembled InGaAs quantum dot coupled to a nearby (similar to 25 nm) plasmonic antenna. Microphotoluminescence spectroscopy shows a similar to 2.4x increase of intensity, which is attributed to spatial far-field redistribution of the emission from the quantum dot-antenna system. Power-dependent studies show similar saturation powers of 2.5 mu W for both coupled and uncoupled quantum dot emission in polarization-resolved measurements. Moreover, time-resolved spectroscopy reveals the absence of Purcell enhancement of the quantum dot coupled to the antenna as compared with an uncoupled dot, yielding comparable exciton lifetimes of tau similar to 0.5 ns. This observation is supported by numerical simulations, suggesting only minor Purcell-effects of <2x for emitter-antenna separations >25 nm. The observed increased emission from a coupled quantum dot-plasmonic antenna system is found to be in good qualitative agreement with numerical simulations and will lead to a better understanding of light-matter coupling in such semiconductor-plasmonic hybrid systems. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)