On the use of Purcell factors for plasmon antennas

Opt Lett. 2010 Dec 15;35(24):4208-10. doi: 10.1364/OL.35.004208.


The Purcell factor is the standard figure of merit for spontaneous emission enhancement in microcavities and has also been proposed to describe emission enhancements for plasmonic resonances. A comparison of quality factor, mode volume, and Purcell factor for single and coupled plasmon spheres to exact calculations of emission rates shows that a Purcell factor derived from quality factor and mode volume does not describe emission changes due to plasmon antennas.