Purcell factor enhanced scattering efficiency in optical microcavities
Scattering processes in an optical microcavity are investigated for the case of silicon nanocrystals embedded in an ultra-high Q toroid microcavity. Using a novel measurement technique based on the observable mode-splitting, we demonstrate that light scattering is highly preferential: more than 99.8% of the scattered photon flux is scattered into the original doubly-degenerate cavity modes. The large capture efficiency is attributed to an increased scattering rate into the cavity mode, due to the enhancement of the optical density of states over the free space value and has the same origin as the Purcell effect in spontaneous emission. The experimentally determined Purcell factor amounts to 883.
Additional InformationWe thank Prof. S. Roorda (Université de Montréal) for Si ion implantation. This work was funded by the DARPA, the NSF, and the Caltech Lee Center. The Dutch part of this work is part of the research program of FOM, which is financially supported by NWO. A.T. is grateful to the Fonds NATEQ (Québec, Canada) for a postdoctoral scholarship. T.J.K. acknowledges a postdoctoral scholarship from the IST-CPI. The authors acknowledge Dr. Oskar Painter for valuable discussions.
Submitted - 0505106.pdf