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$\mu \mathrm{m}$ 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.

References in corpus (13)

• Fiber Fabry-Perot cavity with high finesse
• A single ion coupled to an optical fiber cavity
• A Quantum Network Node with Crossed Optical Fibre Cavities
• A small mode volume tunable microcavity: development and characterization
• Frequency splitting of polarization eigenmodes in microscopic Fabry-Perot cavities
• Room-temperature quantum optomechanics using an ultra-low noise cavity
• Cavity-induced anti-correlated photon emission rates of a single ion
• Laser cooling a membrane-in-the-middle system close to the quantum ground state from room temperature
• Direct laser-written optomechanical membranes in fiber Fabry-Perot cavities
• Dynamical backaction in an ultrahigh-finesse fiber-based microcavity
• Coherent Coupling of a Diamond Tin-Vacancy Center to a Tunable Open Microcavity
• Profile control of fibre-based micro-mirrors using adaptive laser shooting with $\text{in situ}$ imaging
• Motional sideband asymmetry of a solid-state mechanical resonator at room temperature