A scanning planar Yagi-Uda antenna for fluorescence detection

Nano-antennas represent a modern approach to enhance the detection of quantum emitters, but they often require sophisticated nanofabrication techniques and great control over the antenna-emitter distance in three dimensions. Recently, we demonstrated that planar antennas can beam light into a narrow cone, hence providing a large collection efficiency even for low numerical-aperture (NA) optics [1] , [2] . Planar antennas operate like optical Yagi-Uda antennas, where the reflector element is a flat mirror and the director element is a thin metal film. Therefore, they are easier to fabricate and require position control in only one dimension.