Design and optimization of a low frequency electric field sensor using Pockels effect

The present paper proposes an optical device for measuring low frequency (50-60 Hz) high electric fields (0-200 kV.cm^-1) using a LiNbO₃ crystal as sensing medium without any contacting electrode. Thus a good galvanic insulation of material and person is obtained. An experimental set-up is developed in the laboratory by using the electrooptical effect or Pockels effect and several measurements are realized. Simulations are performed with Finite Element Method to optimize the sensing medium of the device. Experimental and simulation results are presented and discussed. The sensor induces a weak disturbance of the local electric field to be measured. A good linearity and reproducibility are obtained, the sensibility of the sensor being about 3 μA/(kV.cm^-1)