Study On Preparation And Performance Of Metal-Coated BRAGG Grating Sensor

Bragg fiber grating sensor has the low electromagnetic interference,light quality and high sensitivity special properties.It is a kind of rising basic fiber optic components in the world since the 1990s. When the temperature or stress of the grating has change,it will lead the grating cycle and fiber core refractive index to change,and the FBG wavelength will drift.Through the wavelength drift can measure the change of temperature and stress.This study chooses the naked FBG, and coat a layer of nickel film in the naked fiber surface by the method of chemical nickel plating to make the substrate ingredient mainly for SiO2 optical fiber surface fully metallization. Sn-10Al alloy was prepared with a vacuum induction melt furnace,and metal-based nickel plating Bragg grating sensor composite was obtained with a good resistance to high temperature,increasing sensitive coefficient.With metallographic microscope to observe the surface morphology of nickel plating optical fiber. The bonding force between the film and the optical fiber matrix were measured with thermal vibration test. The adapted temperature of the compound sensor was got by changing the content of Sn in the alloy. The properties of the sensor were marked and measured through changing temperature and three point bending test.Through these experiments, the results of the study show that optical fiber has higher temperature resistant after chemical nickel plating. The fiber and alloy could combine into a new sensor after metallization. The sensor packaged with Sn-10Al alloy could be used under 350℃, and its sensitive coefficient was two times as much as bare optical fiber sensor. At the same time, this metal matrix compound sensor could be joined with the metal components through brazing, therefore, it could be used more widely.