Tuning of resonant doublets in coupled optical cavities

TL;DR

This paper introduces a new technique for tuning and stabilizing the frequency splitting of resonant doublets in strongly coupled optical cavities, addressing challenges in controlling such systems for advanced sensing applications.

Contribution

A novel method for simultaneous frequency stabilization and fine-tuning of resonant doublets in strongly coupled optical cavities is proposed.

Findings

Enables precise control of frequency splitting in coupled cavities

Facilitates improved cavity stabilization in quantum and gravitational sensing

Addresses challenges in strong coupling regimes

Abstract

The mode profile of a coupled optical cavity often exhibits a resonant doublet, which arises from the strong coupling between its sub-cavities. Traditional readout methods rely on setting fields of different frequencies to be resonant in either sub-cavity, which is challenging in the case of strong coupling. In this regime, the coupled cavity behaves as a single resonator, and a field must be resonant in all its parts. Consequently, specialized sensing schemes are necessary to control strongly coupled cavities. To address this issue, we propose a novel technique for the relative measurement of the degrees of freedom of a strongly coupled cavity. Our approach enables simultaneous frequency stabilization and fine-tuning of frequency splitting in the resonant doublet. Overall, our proposed technique offers a promising solution to control the properties of coupled cavities, facilitating advanced applications in the fields of gravitational-wave detection, quantum cavity optomechanics, and other related areas.