Propylene Carbonate Based Compact Fiber Mach-Zehnder Interferometric Electric Field Sensor

We demonstrate a compact fiber Mach-Zehnder (MZ) interferometric electric field sensor by splicing a short section of single mode fiber between two sections of single mode fibers with a large lateral offset of 62.5 mu m, where the propylene carbonate is filled into the open arm of the interferometer. Based on the Kerr electro-optic effect of propylene carbonate, the applied intensive transient electric field can change the refractive index of propylene carbonate, which shifts the interferometric fringe. The electrical field intensity could be demodulated by monitoring the fringe shift. In the experiment, high voltages from 10.67 kV to 23.3 kV are applied to our sensor through parallel-plate electrodes. More than 150 kV/cm electrical field intensity in the middle place of the parallel-plate electrodes is measured when the voltage is 23.3 kV, and the sensitivity is similar to 0.1 w (v/m). Such kind of safe sensor has good stability, high reproducibility, compact size, lightweight and easy fabrication, making it attractive for applications in measuring different kinds of electric field, especially when the measurement space is limited or closed.