Excitation of whispering gallery modes with a "point-and-play," fiber-based, optical nano-antenna

Opt Lett. 2019 Jul 1;44(13):3386-3389. doi: 10.1364/OL.44.003386.

Abstract

We demonstrate the excitation and detection of whispering gallery modes in optical microresonators using a "point-and-play," fiber-based, optical nano-antenna. The coupling mechanism is based on cavity-enhanced Rayleigh scattering. Collected spectra exhibit Lorentzian dips, Fano shapes, or Lorentzian peaks, with a coupling efficiency around 13%. The spectra are characterized by the coupling gap, polarization, and fiber tip position. The coupling method is simple, low-cost and, most importantly, the Q-factor can be maintained at 108 over a wide coupling range, thereby making it suitable for metrology, sensing, or cavity quantum electrodynamics experiments.