| Fiber Bragg grating (FBG) has the potential to be widely used as sensors in environmental applications, chemical industry, construction industry, air plane, and so on, for its advantages such as immunity to electromagnetic interference, high sensitivity, small size. In order to the high temperature resistance protect, gaining good bonding with metal material, the fiber Bragg grating should be metalized. Because of the small optical and thermal coefficient of the fiber-optic materials, the fiber grating temperature sensitivity is very low. So for using FBG as the temperature sensor, the temperature sensitivity should be increased. With the metal coat for packaging and protection, the temperature sensitivity of FBG can be effectively increased. This dissertation shows the method for FBG high temperature resistance protection and the temperature-sensitivity enhancing of FBG after protection. The main works are as follows:(1) A pretreatment process for electroless plating on the surface of optical fiber was presented, including removing of organic coating, grease removing, coarsening, sensitization, activation and heat treatment.(2) The compositions of electroless plating solutions were optimized, based on the systemic analysis of electroless plating experiments for nickel and copper.(3) Using a thin copper coat as the conductive layer the nickel plating was carried out, after experiments and analysis the optimized composition of plating solution was acquired.(4) The temperature sensing performance of FBGs were studied, including the bare FBG, electroless Ni-plating FBG, electroless Cu-plating FBG, Cu/Ni-plating duplex layers coating FBG, the temperature sensitivity were acquired. At the same time, the impact of packaging materials over FBG temperature sensitiveness was analyzed.(5) The metallized FBG was embedded into 42CrMo steel successfully and a smart metal part was acquired.The temperature sensitivity of the bare FBG was successfully enhanced after metalized. |
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