Permanent matching of coupled optical bottle resonators with better than 0.16 GHz precision

TL;DR

This paper demonstrates the fabrication of two coupled optical bottle microresonators with a resonance matching precision better than 0.16 GHz, significantly surpassing previous post-processing methods and enabling more precise photonic circuits.

Contribution

The authors achieve a record-level permanent resonance matching precision of better than 0.16 GHz in coupled microresonators, improving fabrication accuracy beyond existing post-processing techniques.

Findings

Resonance matching precision better than 0.16 GHz achieved

Corresponds to 0.17 Å in fiber radius variation

Precision limited only by spectrum analyzer resolution

Abstract

The fabrication precision is one of the most critical challenges on the way to the creation of practical photonic circuits composed of coupled high Q-factor microresonators. While very accurate transient tuning of microresonators based on local heating has been reported, the record precision of permanent resonance positioning achieved by post-processing is still within 1-5 GHz. Here we demonstrate two coupled bottle microresonators fabricated at the fiber surface which resonances are matched with a better than 0.16 GHz precision. This corresponds to a better than 0.17 angstrom precision in the effective fiber radius variation. The achieved fabrication precision is only limited by the resolution of our optical spectrum analyzer and can be potentially improved by an order of magnitude.