Abstract

An optical antenna can be used to control the radiation properties of a quantum emitter such as single fluorescent molecules [1]. The antenna modifies local density of optical states (LDOS), when brought in near-field of such emitters, changing the ease at which they emit photons. This effect is realized as change in the excited state lifetime of the molecule. The LDOS and thus lifetime is sensitive to both orientation of the molecule dipole and its position with respect to electromagnetic field around the antenna. In past, several studies have been performed to map the LDOS, but were focused on a particular molecule orientation, and positioned within the antenna hotspot [2-4]. Here, we show the LDOS mapping of a resonant optical dipole antenna at all the positions over a resonant antenna, probed using various molecule orientations.

© 2015 IEEE