A small mode volume tunable microcavity: Development and characterization

作者：Greuter Lukas^*; Starosielec Sebastian; Najer Daniel; Ludwig Arne; Duempelmann Luc; Rohner Dominik; Warburton Richard J

来源：Applied Physics Letters, 2014, 105(12): 121105.

DOI：10.1063/1.4896415

We report the realization of a spatially and spectrally tunable air-gap Fabry-Perot type microcavity of high finesse and cubic-wavelength-scale mode volume. These properties are attractive in the fields of opto-mechanics, quantum sensing, and foremost cavity quantum electrodynamics. The major design feature is a miniaturized concave mirror with atomically smooth surface and radius of curvature as low as 10 mu m produced by CO2 laser ablation of fused silica. We demonstrate excellent mode-matching of a focussed laser beam to the microcavity mode and confirm from the frequencies of the resonator modes that the effective optical radius matches the physical radius. With these small radii, we demonstrate wavelength-size beam waists. We also show that the microcavity is sufficiently rigid for practical applications: in a cryostat at 4 K, the root-mean-square microcavity length fluctuations are below 5 pm.

• 出版日期2014-9-22