Inhibition and Enhancement of the Spontaneous Emission of Quantum Dots in Micropillar Cavities with Radial-Distributed Bragg Reflectors

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• 作者：Tomasz Jakubczyk ; Helena Franke ; Tomasz Smole艅ski ; Maciej 艢ciesiek ; Wojciech Pacuski ; Andrzej Golnik ; R眉diger Schmidt-Grund ; Marius Grundmann ; Carsten Kruse ; Detlef Hommel ; Piotr Kossacki
• 刊名：ACS Nano
• 出版年：2014
• 出版时间：October 28, 2014
• 年：2014
• 卷：8
• 期：10
• 页码：9970-9978
• 全文大小：483K
• ISSN：1936-086X

文摘

We present a micropillar cavity where nondesired radial emission is inhibited. The photonic confinement in such a structure is improved by implementation of an additional concentric radial-distributed Bragg reflector. Such a reflector increases the reflectivity in all directions perpendicular to the micropillar axis from a typical value of 15鈥?1% to above 98%. An inhibition of the spontaneous emission of off-resonant excitonic states of quantum dots embedded in the microcavity is revealed by time-resolved experiments. It proves a decreased density of photonic states related to unwanted radial leakage of photons out of the micropillar. For on-resonance conditions, we find that the dot emission rate is increased, evidencing the Purcell enhancement of spontaneous emission. The proposed design can increase the efficiency of single-photon sources and bring to micropillar cavities the functionalities based on lengthened decay times.

Keywords:

micropillar cavity; quantum dot; spontaneous emission inhibition; leaky mode; radial-distributed Bragg reflector; Purcell effect