A high-reflectivity high-Q micromechanical Bragg-mirror

摘要

We report on the fabrication and characterization of a micromechanicaloscillator consisting only of a free-standing dielectric Bragg mirror with highoptical reflectivity and high mechanical quality. The fabrication technique isa hybrid approach involving laser ablation and dry etching. The mirror has areflectivity of 99.6%, a mass of 400ng, and a mechanical quality factor Q ofapproximately 10^4. Using this micromirror in a Fabry Perot cavity, a finesseof 500 has been achieved. This is an important step towards designing tunablehigh-Q high-finesse cavities on chip.