Enhancing Fluorescence of Diamond Color Centers near Gold Nanorods via Geometry Optimization

M. Csete [1], A. Szenes [1], L. Zs. Szabó [1], G. Szabó [1], T. Csendes [2], B. Bánhelyi [2],
[1] Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
[2] Institute of Informatics, University of Szeged, Szeged, Hungary

Detecting light emitted by fluorescent molecules with resolution down to single photon is an important problem in various fields of sciences and applications, such as solid-state physics, quantum information processing and medicine. The detection probability can be improved via enhancement of excitation and emission. Enhancement both of these processes can be reached by localized surface plasmon resonance (LSPR) of metal nanoparticles. However, the properties of LSPRs is strongly material and shape dependent. To obtain the optimal geometric parameters of the plasmonic structure – emitter coupled system numerical calculations needed. Our purpose was to determine the optimal configuration of the gold nanorod – emitter coupled system to enhance excitation or emission. At 738 nm and 650 nm emission wavelengths, the two used optimization approaches have found an optimal configuration, in which the nanorod geometry is tuned into the LSPR bands at the wavelengths of interest.