One kind of fiber Bragg grating displacement sensor using micro-elastic spring

A kind of fiber Bragg grating displacement sensor using micro-elastic spring is proposed and studied in this paper. A type of micro-elastic spring was used as a displacement-wavelength conversion component. According to the sensor package design established, one micro FBG displacement sensor with outer diameter of 1.3mm was constructed. Tests were designed and conducted to study the displacement and temperature sensitivity of the sensor. Results show that there are good linear relationships between wavelength and displacement, as well as between wavelength and temperature. The displacement coefficient and temperature coefficient are 10.97pm/mm, and 21.38pm/°C, respectively. To obtain smaller displacement resolution of the sensor, one kind of sensitivity inhenced FBG displacement sensor is proposed and studied, the displacement coefficient is 110pm/mm.