5 research outputs found
Coupled T‑Shaped Optical Antennas with Two Resonances Localized in a Common Nanogap
Resonant optical antennas with nanoscale
gaps are of high interest due to their ability to enhance electric
fields in localized subdiffraction-limited volumes. They are especially
attractive for coupling with quantum emitters. One challenge for applications
that exhibit a spectral shift is to fabricate nanoantennas that provide
two distinct resonances at the excitation and emission frequency,
respectively. We propose a coupled T-shaped nanoantenna structure
that provides independently controllable resonances with a common
electromagnetic hot spot in the antenna gap. We demonstrate the fabrication
of such structures and investigate experimentally and theoretically
their spatial, time-integrated spectral- and polarization-dependent
electromagnetic field properties. The nanoantennas exhibit two resonances
with unique spectral and polarization responses. The resonance wavelengths
are independently tailored by varying the geometry of individual T-shaped
antennas