Relationship between discharge current and torsional characteristics of LPFG based on micro taper structure

In this paper, a long-period fiber grating based on microconical structure was proposed, which uses arc discharge technology to perform periodic discharge in ordinary single-mode fiber, so that the refractive index between the fiber core and the cladding is periodically modulated, thus forming LPFG. In this paper, three kinds of current were used to prepare samples. The experimental results show that, with a moderate increase in the discharge current, the sensor exhibits good directional discrimination within a torsion range of −360° to +360°. The wavelength and intensity torsional sensitivity reached −0.1805 nm/(rad/m) and 0.04199 dB/(rad/m), respectively, indicating that such sensors are expected to be candidates for high-performance torsional sensors.