All-optical switching and strong coupling using tunable whispering-gallery-mode microresonators

TL;DR

This paper reviews tunable whispering-gallery-mode microresonators with ultrahigh quality factors, demonstrating their applications in nonlinear and quantum optics, including all-optical switching and progress towards strong atom-cavity coupling.

Contribution

It introduces a tunable microresonator platform with ultrahigh Q factors and demonstrates its use in nonlinear optical switching and atom coupling experiments.

Findings

Achieved Q factors up to 3.6 x 10^8.

Demonstrated efficient all-optical switching via Kerr effect.

Progress towards strong atom-resonator coupling.

Abstract

We review our recent work on tunable, ultrahigh quality factor whispering-gallery-mode bottle microresonators and highlight their applications in nonlinear optics and in quantum optics experiments. Our resonators combine ultra-high quality factors of up to Q = 3.6 \times 10^8, a small mode volume, and near-lossless fiber coupling, with a simple and customizable mode structure enabling full tunability. We study, theoretically and experimentally, nonlinear all-optical switching via the Kerr effect when the resonator is operated in an add-drop configuration. This allows us to optically route a single-wavelength cw optical signal between two fiber ports with high efficiency. Finally, we report on progress towards strong coupling of single rubidium atoms to an ultra-high Q mode of an actively stabilized bottle microresonator.