Electroless Nickel Plating and Electroplating on FBG Temperature Sensor

Metal-coated fiber Bragg grating(FBG) temperature sensors were prepared via electroless nickel(EN) plating and tin electroplating methods on the surface of normal bare FBG. The surface morphologies of the metal-coated layers were observed under a metallographic microscope. The effects of pretreatment sequence, pH value of EN plating solution and current density of electroplating on the performance of the metal-coated layers were analyzed. Meanwhile, the Bragg wavelength shift induced by temperature was monitored by an optical spectrum analyzer. Sensitivity of the metal-coated FBG(MFBG) sensor was almost two times that of normal bare FBG sensor. The measuring temperature of the MFBG sensor could be up to 280 °C, which was much better than that of conventional FBG sensor.