High Voltage Sensing Based on Fiber Fabry–Perot Interferometer Driven by Electric Field Forces

Based on the mechanism of the liquid flow caused by charged particles and dielectrophoresis under electric field-induced forces, an optical fiber Fabry-Perot interferometer for measuring high voltage is proposed and demonstrated. A second-order equation is established to express the relationship between the voltage signal and the output light signal. In our experiment, both sinusoidal signal with 7 kV, 50 Hz, and instantaneous pulse signal with dozens of kilovolts are employed as testing voltage sources. The results show that when the pulse voltage is applied, the output light signal exhibits a waveform near to the impulse response of a second-order system. A formula is derived to reveal the feature of linear and quadratic voltage effects in the experiment. As for ac voltage response of 50 Hz, the output light waveforms show only ~0.1 ms delay. There is a good agreement between the theory and the experimental result. Moreover, there is no need to use expensive materials and polarization devices in the scheme. Our proposed sensing technique has the potential to measure high pulse voltage or the periodic high voltage.