Optical fiber bend sensor based on fiber Bragg grating in germano-silicate glass optical fiber with depressed-index structure

摘要

An optical fiber bend sensor based on a fiber Bragg grating by using a germano-silicate glass optical fiber with depressed-index structure has been developed and its novel bend sensing characteristics was demonstrated. With the increase of bending, the transmission spectrum was linearly blue-shifted without change of optical transmission loss. Total blue-shift of the Bragg reflection wavelength upon bending in the radius of curvature from 20 m~(-1) to 133 m~(-1) was -0.13nm.