Controlled by an optical switch

a fiber Bragg grating sensing system based on spatial division multiplexing is developed under a broad-band source illumination. With an isosceles triangle cantilever beam to realize linear tuning of Bragg wavelength of fiber grating without chirping

the system employs an unbalanced Mach-Zehnder interferometer to translate the FBG wavelength signal into phase signal. The strain can be recovered by measuring the phase change with signal processing circuit. With a high resolution characteristic and wide measurement range

this sensor system has the capability of measuring static strain as well as dynamic strain. Experiment demonstrates that the sensing sensitivity of this system is resolution of 7.3/με

and experimental sensitivity of 0.82°/με.