Mode matching for Optical Antennas

The emission rate of a point dipole can be strongly increased in presence of a well designed optical antenna. Yet, optical antenna design is largely based on radio frequency rules, ignoring e.g. ohmic losses and non negligible field penetration in metals at optical frequencies. Here we combine reciprocity and Poynting s theorem to derive a set of optical frequency antenna design rules for benchmarking and optimizing the performance of optical antennas driven by single quantum emitters. Based on these findings a novel plasmonic cavity antenna design is presented exhibiting a considerably improved performance compared to a reference two wire antenna. Our work will be useful for the design of high performance optical antennas and nanoresonators for diverse applications ranging from quantum optics to antenna enhanced single emitter spectroscopy and sensin