Study of sensing properties of quartz fiber Bragg grating sensor based on metalized encapsulation

Surface of quartz fiber Bragg grating (QFBG) was metalized by means of electroless plating method. Two different encapsulation processes were proposed. Temperature and strain sensing properties were studied based on two different encapsulation of the QFBG. The results indicate that linearity and repeatability of the center wavelength of the QFBG sensor using metalized encapsulation with temperature or strain change are better than that of sensor encapsulated by adhesive, and its linear correlation coefficient at least reaches 0.9996, almost no hysteretic phenomenon. In addition, temperature sensing ability of metalized encapsulation of the QFBG sensor can be improved to 24.4 pm/°C, which is 2.3 times as much as that of the QFBG sensor used adhesive encapsulation. Metalized encapsulation not only improves sensing characteristics of the QFBG sensor, and greatly expands its application scope.