TOTAL INTERNAL REFLECTION TYPE EXTRINSIC FABRY-PEROT INTERFEROMETRIC FIBER SENSOR AND METHOD FOR MEASURING STRAIN USING THE SAME

摘要

PURPOSE: A total internal reflection type extrinsic fabry-perot interferometric fiber sensor and a method for measuring strain using the same are provided to measure the deformation magnitude of an object to be measured by using generation frequency of interference fringe and distinguish deformation direction. CONSTITUTION: A total internal reflection type extrinsic fabry-perot interferometric fiber sensor includes a single-mode fiber(51) inserted into one side of a capillary glass tube(52), a metal-plated fiber(53) inserted into the other side of the capillary glass tube to be separated from the end of the single-mode fiber, a laser irradiating light to the end of the single-mode fiber which have not inserted into the capillary glass tube, and a light detector sensing an interference fringe of the lights returned to the single-mode fiber by the single-mode fiber and an air gap(54) between the single-mode fiber and the metal-plated fiber, wherein the generation frequency and signal level change tendency are changed by changing the length of the air gap according to the change of the capillary glass tube in magnitude and direction if the change is generated in the capillary glass tube in longitudinal direction.