Optical fiber strain sensor with double S-tapers

Abstract

An optical fiber Mach–Zehnder interferometer based on double S-tapers is proposed for strain sensing. The double S-taper strain sensor is formed by two steps. The fiber is pulled during arc discharging, and a second arc discharge is performed while the fixtures are misaligned to form a S-taper. The transmission spectra were collected with different structural parameters, including the axial offset, taper region diameter, and transition region length. The transmission spectra of each group of parameters are compared and analyzed. This work is meaningful for further research on double S-taper strain sensors. When the axial offset is 60 μm, the S₂-taper region diameter is 54 μm, the transition region length is 0.7 cm, the strain experiment is tested from 0 με to 800 με, and the strain sensitivity is 6.63 pm/με. In addition, the stability, reversibility, and temperature sensitivity were experimentally characterized.

Keywords:

• Double S-tapers
• Mach–Zehnder interferometer
• optical fiber strain sensor

Acknowledgements

This work was supported in part by the National Natural Science Foundation of China under Grants 61933004 and 61773102, and in part by the State Key Laboratory of Synthetical Automation for Process Industries under Grant 2013ZCX09.