I. Introduction
At present, traditional voltage transformers in power systems have disadvantages such as large size, small dynamic range, complex insulation structure, and poor transient performance [1]–[2], which is not conducive to the development of multi-dimensional, broadband and miniaturization of electric field measurement the commonly used electric field measurement sensors mainly include optical sensors. Optical sensors are mainly divided into two categories, One is the Pockels effect sensor [3]–[6] and Kerr electric field sensor [7]–[8] based on the photoelectric effect.