Tuning of optical resonances in asymmetric microtube cavities

Institute for Integrative Nanosciences, Leibniz-Institut für Festkörper-und Werkstoffforschung Dresden, Helmholtzstrasse 20, D-01069 Dresden, Germany.
Optics Letters (Impact Factor: 3.18). 10/2011; 36(19):3840-2. DOI: 10.1364/OL.36.003840
Source: PubMed

ABSTRACT We tune optical resonances in rolled-up SiO/SiO(2) microtube cavities by gradually modifying the tube structure through asymmetrical postdeposition of SiO(2). Spectral blueshifts followed by redshifts of the resonant modes are observed in a thin-walled microtube (tube-I), which is attributed to a competition between shape deformation and effective increase of tube wall thickness. In contrast, only a monotonic redshift is detected when asymmetrical deposition is performed on a thick-walled microtube (tube-II). Distinct wavelength-dependent tuning was revealed in both kinds of tubes. Numerical calculations based on perturbation theory are carried out to explain and confirm the experimental results.

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