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arXiv · 2601.19799

Widely tunable SNAP microresonators via translation of side-coupled optical fibers

Isha Sharma·Misha Sumetsky
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Abstract

We demonstrate free spectral range (FSR) tunable Surface Nanoscale Axial Photonics (SNAP) microresonators induced by side-coupled parallel optical fiber segments. By translating one segment relative to the other, we tune the coupling length from $900~\mu$m to $100~\mu$m and thereby tune the microresonator FSR from $5$ pm to $50$ pm, with an estimated precision of better than $0.003$ pm. The microresonator Q-factor exceeds $10^5$ and can potentially be significantly increased in a clean lab environment. Possible applications of the demonstrated device include miniature and low-loss tunable delay lines and optical frequency comb generators, as well as ultraprecise tunable optical sensors.

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Isha Sharma, Misha Sumetsky. 2026-01-27. Widely tunable SNAP microresonators via translation of side-coupled optical fibers. https://arxiv.org/abs/2601.19799

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