Current sensing characteristics of the helical long-period fiber grating written in polarization maintaining fiber

An optical fiber current sensor based on helical long-period fiber grating (HLPG) inscribed in polarization-maintaining fiber (PMF) by CO2 laser has been proposed. The PMF-HLPG is put into the solenoids with a direct current (DC) current source, and the value of applied current can be measured by monitoring the rotation angle of the input elliptical polarized light due to the changes of the magnetic field along the grating. The main factors that affect the rotation angle have been investigated experimentally. The experimental results show a good linear relationship between the rotation angle and the applied current, which indicate that the PMF-HLPG can be used as all fiber current sensor. The maximum sensitivity of the current measurement can be achieved by adjusting the parameters of the input elliptical polarized light. The current sensor based on the PMF-HLPG exhibits high sensitivity even for the detection of small electric current.

Automated summary

An optical fiber current sensor based on a helical long-period fiber grating inscribed in a polarization-maintaining fiber by CO2 laser is proposed. The sensor measures the applied current by monitoring the rotation angle of the input elliptical polarized light, showing good linear relationship between rotation angle and current with high sensitivity.