Tuning of optical resonances in asymmetric microtube cavities
| L. B. Ma, S. Kiravittaya, V. A. Bolaños Quiñones, S. L. Li, Y. F. Mei, O. G. Schmidt Opt. Lett. 36, 3840 (2011) URL PDF | ||
| Abstract | ||
| We tune optical resonances in rolled-up SiO/SiO2 microtube cavities by gradually modifying the tube structure through asymmetrical postdeposition of SiO2. 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. |