Open AccessInhibition and Enhancement of the Spontaneous Emission of Quantum Dots in Micropillar Cavities with Radial-Distributed Bragg Reflectors
Author(s) -
Tomasz Jakubczyk,
Helena Franke,
T. Smoleński,
Maciej Ściesiek,
W. Pacuski,
A. Golnik,
Rüdiger SchmidtGrund,
Marius Grundmann,
C. Kruse,
D. Hommel,
P. Kossacki
Publication year - 2014
Publication title -
acs nano
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.554
H-Index - 382
eISSN - 1936-086X
pISSN - 1936-0851
DOI - 10.1021/nn5017555
Subject(s) - distributed bragg reflector , spontaneous emission , quantum dot , purcell effect , photonics , photon , optoelectronics , materials science , blueshift , resonance (particle physics) , amplified spontaneous emission , photonic crystal , optics , perpendicular , laser , physics , atomic physics , photoluminescence , wavelength , geometry , mathematics
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 15-31% 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.