Fabrication of Efficient Single-Emitter Plasmonic Patch Antennas by Deterministic In Situ Optical Lithography using Spatially Modulated Light.

Single-emitter plasmonic patch antennas are room-temperature deterministic single-photon sources, which exhibit highly accelerated and directed single-photon emission. However, for efficient operation these structures require 3D nanoscale deterministic control of emitter positioning within the device, which is a demanding task, especially when emitter damage during fabrication is a major concern. To overcome this limitation, the deterministic room-temperature in situ optical lithography protocol uses spatially modulated light to position a plasmonic structure nondestructively on any selected single-emitter with 3D nanoscale control. Herein, the emission statistics of such plasmonic antennas that embed a deterministically positioned single colloidal CdSe/CdS quantum dot, which highlight acceleration and brightness of emission, are analyzed. It is demonstrated that the presented antenna induces a 1000-fold effective increase in the absorption cross-section, and, under high pumping, these antennas show nonlinearly enhanced emission.