Elliptical optical fiber transverse load sensor and its temperature self-compensation research
To solve the problem of low sensitivity and temperature cross-sensitivity of optical fiber trans-verse load sensor,an elliptical structure optical fiber transverse load sensor with temperature self-com-pensation is proposed.The sensor is formed by bending a standard single mode fiber(SMF)into an el-liptical structure and encapsulated in polydimethylsiloxane(PDMS).The temperature self-compensation is realized by paralleling another nearly twin elliptical structure of the measuring element.The core mode and cladding mode interfere in the elliptical bending SMF,and the interference spectrum shifts with the change of applied transverse load.The experimental results show that the characteristic wavelengths of the sensor have a linear relationship to the transverse load in the range of 0.25-0.5 N.In the tempera-ture range of 33.5-44 ℃,the sensitivity after temperature self-compensation can reach 6.6 nm/N,the temperature cross sensitivity is only 0.001 5 N/℃,and the temperature self-compensation error is less than 0.089 nm.The proposed transverse load sensor has high sensitivity,low cost and simple structure.It has certain application reference value.