Optical fiber sensor for leakage detection based on side-thrown defect structure

On the basis of optical fiber communication, the side polishing technology forms a "leakage window" for transmitting the light field by removing a length of cladding, and uses the interaction between the light field and matter to excite, control and detect the fiber core.In this paper, the defect structures of fiber fibers of different shapes are obtained by CO2 laser, wheel polishing and reciprocating linear polishing, and we detect the refractive index changes caused by the liquid leakage between the defect structures and LEDs. Experiments have verified that the cylindrical structure side coupling effect of wheeled polishing with a diameter of 0.6mm and a depth of 0.3mm is better, and the rate of change caused by liquid leakage can reach 45%