Bottle microresonator with actively stabilized evanescent coupling

TL;DR

This paper demonstrates active stabilization of evanescent coupling and resonator frequency in a bottle microresonator using Pound-Drever-Hall technique, achieving long-term stability and critical coupling control.

Contribution

It introduces a method for actively stabilizing both evanescent coupling and resonator frequency in a bottle microresonator, enhancing stability for practical applications.

Findings

Achieved a control bandwidth of 0.1 Hz for stabilization.

Maintained residual transmission of (9 ± 3) × 10^-3 for over an hour.

Successfully stabilized the resonator mode frequency.

Abstract

The evanescent coupling of light between a whispering-gallery-mode bottle microresonator and a sub-wavelength-diameter coupling fiber is actively stabilized by means of a Pound-Drever-Hall technique. We demonstrate the stabilization of a critically coupled resonator with a control bandwidth of 0.1 Hz, yielding a residual transmission of (9 \pm 3) \times 10^-3 for more than an hour. Simultaneously, the frequency of the resonator mode is actively stabilized.