Open AccessSilicon nanocrystals on bottle resonators: Mode structure, loss mechanisms and emission dynamics
Author(s) -
Pablo Bianucci,
X. Wang,
Jonathan G. C. Veinot,
A. Meldrum
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.008466
Subject(s) - whispering gallery wave , materials science , resonator , optics , silicon , optoelectronics , photoluminescence , surface roughness , q factor , composite material , physics
Bottle resonators can support high Q-factor whispering gallery modes (WGMs) and demonstrate a rich mode spectrum. Resonators were fabricated using a fiber tapering apparatus and were coated with a thin, smooth layer of luminescent silicon nanocrystals. The photoluminescence spectrum showed WGM peaks with Q-factors near 2,500; however, evanescent measurements showed that these modes are a composite of many modes with Q-factors exceeding 106, the highest yet seen for a silicon-nanocrystalcoated microresonators. The mode structure showed strong polarization and sensitivity to position within the bottle resonator. An analysis of loss mechanisms establishes surface roughness scattering as the limiting factor in these nanocrystal-coated bottle resonators in the absence of excited carriers.