Abstract

Enhancing and extracting light emission from a fluorescent system is a challenging problem, with applications ranging from light-emitting diodes to quantum optics. In particular, efficient single photon sources with enhanced decay rate and well-defined emission direction and polarization are of great interest for quantum cryptography devices. Coupling the emitter to the plasmon mode of a metallic surface is a way to increase decay rate and ensure emission redirection over a broad spectral range. This was demonstrated in a previous paper with colloidal CdSe/ZnS nanocrystals considered at the single-emitter level and coupled to a plane gold surface [1]. The fluorescence decay rate was increased by a factor 7 at 20 nm from a gold surface, and the overall detected fluorescence per nanocrystal was increased by a factor 2.4 at 80 nm from a gold surface. These results can be dramatically improved as most of the emission is lost in non-radiative surface plasmons. For this purpose, we developed and characterised an hybrid metal-dielectric photonic crystal showing a periodically nanostructured metallic surface to couple the surface plasmon mode to the far-field radiation.

© 2011 IEEE