Investigated Solution Concentration Sensors Based on the Etched Phase Shifted Fiber Bragg Grating

Abstract

To remove or reduce the cladding layer thickness of fiber Bragg grating, the refractive index changes in the surrounding environment will affect the fiber Bragg grating effective refractive index of the core, resulting in changes in the Bragg wavelength. Solution concentration changes will cause changes in refractive index of the solution. A new kind of solution concentration sensor is designed with the etched phase shifted fiber Bragg grating, and concentration sensing detection with four kinds of solutions is experimentally demonstrated. With resolution concentration increasing, the phase shifted label wavelength shifts to the red, and the sensor is more sensitive in the case of higher concentration.