Abstract

Dipole-Dipole resonant coupling is a common mechanism for short-range energy transfer (ET), typicall occurring over a range of several nm. Surface plasmons (SP) may enhance ET and indeed, it was demonstrated that SP on opposite sides of a thin metallic film may extend the ET range by carrying the donor emission to the acceptor [1,2], when both are located close to the metal. Here we demonstrate that a metallic microcavity, designed to couple plasmonic and intra-cavity photonic modes [3] can further extend the ET range, exceeding 100 nm. Our structure (shown schematically in Fig. 1a) is /2 microcavity made by two silver mirrors separated by a 150 nm thick polymer (PVA, refractive index ~1.5) and it supports cavity-confined photons as well as surface plasmons on the top metal-air interface. When the dispersion curves of the SP and cavity-photon cross, the two modes resonantly-couple due to their field overlap and normal-mode splitting is observed (Fig. 1b). Around that point hybrid modes form, which are linear combinations of both the photonic and the plasmonic modes, with their field distribution residing both outside and inside the cavity, as shown in Fig. 1a.

© 2015 IEEE