A Dispersion sensor using Whispering Gallery Modes in Cylindrical Micro-cavity

作者:Yang Rui; Bao Yang; Yu Wen Hua; Wang Xiang Long; Ren Yi Tao; Pu Xiao Yun*
来源:nternational Conference on Optical Instruments and Technology - Advanced Sensor Technologies and Applications, 2008-11-16 to 2008-11-19.
DOI:10.1117/12.806922

摘要

Whispering gallery modes (WGM) in a cylindrical micro-cavity of a silica optical fiber are excited with a tapered fiber of similar to 7 mu m in diameter by evanescence field, and the WGM spectra of the cylindrical micro-cavity with different diameters (300 mu m, 400 mu m and 500 mu m) are measured. The resonant positions and their separations of the spectra are assigned precisely by an asymptotic formula. Considering the fiber dispersion and the errors induced from it, the values of the resonant position and its separation achieved from assignment within the experimental spectra rang(1290 similar to 1320 nm) match well with a theoretical calculation and a measured accuracy of the refractive index of the micro-cavity can be as high as 10(-5), which indicates that a dispersion sensor can be formed by measuring the dispersive features of WGM in a cylindrical micro-cavity.

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