High-yield fabrication of micromirror templates via feedback-controlled laser ablation
Abstract
We present a high-yield method for fabricating concave micromirror templates in silica using feedback-controlled CO2 laser ablation with precise in situ positioning. Real-time monitoring of the white-light emission generated during ablation is used to terminate laser exposure, thereby reducing shot-to-shot variability in mirror depth and radius of curvature. To ensure reproducible single-shot processing across different substrates, the sample position relative to the laser focus is calibrated using an in situ phase-scanning interferometric microscope integrated into the fabrication workflow. The method enables reliable fabrication of shallow mirror templates with tunable radii of curvature spanning from approximately 20 to several hundred micrometers, with relative geometric variances as low as 3%. The suitability of the fabricated mirrors for optical resonators is verified by realizing a compact plano-concave Fabry--Perot microcavity with a finesse of 37000 at telecom wavelengths. The setup provides a simple and automated route to reproducible micromirror fabrication for applications in cavity quantum electrodynamics and cavity optomechanics.
Keywords
Cite
@article{arxiv.2604.16150,
title = {High-yield fabrication of micromirror templates via feedback-controlled laser ablation},
author = {Daniel Allepuz-Requena and Jonas Schou Neergard-Nielsen and Alexander Huck and Ulrik Lund Andersen},
journal= {arXiv preprint arXiv:2604.16150},
year = {2026}
}