Scanning planar Yagi-Uda antenna for fluorescence detection

Year: 2021

Authors: Soltani, Navid; Esfahany, Elham Rabbany; Druzhinin, Sergey, I; Schulte, Gregor; Mueller, Julian; Sledz, Florian; Flatae, Assegid Mengistu; Butz, Benjamin; Schoenherr, Holger; Markesevic, Nemanja; Agio, Mario

Autors Affiliation: Laboratory of Nano-Optics, University of Siegen, Siegen 57072, Germany; Research Center for Micro and Nano-Chemistry and Engineering (Cμ), Siegen 57076, Germany; Physical Chemistry I, University of Siegen, Siegen 57076, Germany; Micro- and Nanoanalytics Group, University of Siegen, Siegen 57076, Germany; Currently with Nanoscience Center, University of Jyväskylä, Jyväskylä 40014, Finland; National Institute of Optics (INO), National Research Council (CNR), Florence 50125, Italy

Abstract: An effective approach to improve the detection efficiency of nanoscale light sources relies on a planar antenna configuration, which beams the emitted light into a narrow cone. Planar antennas operate like optical Yagi-Uda antennas, where reflector and director elements are made of metal films. Here we introduce and investigate, both theoretically and experimentally, a scanning implementation of a planar antenna. Using a small ensemble of molecules contained in fluorescent nanobeads placed in the antenna, we independently address the intensity, radiation pattern, and decay rate as a function of distance between a flat-tip scanning gold wire (reflector) and a thin gold film coated on a glass coverslip (director). The scanning planar antenna changes the radiation pattern of a single fluorescent bead, and it beams light into a narrow cone down to angles of 45∘ (full width at half maximum). Moreover, the collected signal compared to the case of a glass coverslip is larger than a factor of three, which is mainly due to the excitation enhancement. These results offer a better understanding of the modification of light–matter interaction by planar antennas, and they hold promise for applications such as sensing, imaging, and diagnostics.

Journal/Review: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B: OPTICAL PHYSICS

Volume: 38 (9)      Pages from: 2528  to: 2535

KeyWords: optical antennas, fluorescence detection
DOI: 10.1364/JOSAB.434980

Citations: 2
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2022-06-26
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