English

Few-MHz bandwidth tunable optical filter based on a fiber-ring resonator

Optics 2025-06-16 v1 Quantum Physics

Abstract

We present a fiber-ring resonator that realizes an ultra-narrowband, high-extinction, low-loss, tunable optical filter. It consists of a pair of commercial variable ratio directional couplers that allow precise adjustment of the filter bandwidth and its on-resonance transmission. This design also grants access to multiple modes of operation, such as a simultaneous band-stop and band-pass filter. Our characterization reveals a bandwidth of less than 2 MHz, together with an extinction exceeding 20 dB. The tunability of the filter properties establishes our device as a versatile platform for selective frequency filtering with sub-natural atomic linewidth resolution.

Keywords

Cite

@article{arxiv.2506.11953,
  title  = {Few-MHz bandwidth tunable optical filter based on a fiber-ring resonator},
  author = {Gabriele Maron and Anton Bölian and Xin-Xin Hu and Luke Masters and Arno Rauschenbeutel and Jürgen Volz},
  journal= {arXiv preprint arXiv:2506.11953},
  year   = {2025}
}

Comments

6 pages, 7 figures

R2 v1 2026-07-01T03:16:12.669Z