Research On Electric Field Measurement Method Based On BGO Crystal

Electric field measurement has important applications in engineering practice.The optical electric field sensor overcomes the shortcomings of the traditional charge induction electric field sensor and has broad development prospects.This article takes BGO crystal Pockels optical sensor as the research object.With the help of wave coupled theory of linear electro-optic,some design parameters of sensors were simulated and optimized.An optical electric field sensor measurement system was built,the parameters were calibrated,and preliminary electric field measurement experiments were carried out.This article gives some advices for sensor installation.The main research results are as follows:1.The content of the wave coupled theory of linear electro-optic effect has been studied,and some simulation programs have been write by using Matlab software.The sensor device is analyzed and a mathematical model is established.The refractive index ellipsoid theory is used to verify the correctness of the wave coupled theoretical program calculation,which lays a foundation for the simulation of the sensor.2.In different light paths,the position of the transmission axis of the polarizer directly affects the modulation depth of the sensor.We find the best direction of the transmission axis of the polarizer to maximize the modulation depth of the sensor,which improved the sensitivity and resolution of the sensor.We also considered the influence of the deviation angle on the sensor during the calibration of the polarizer.3.The change of direction of the external electric field will affect the output light intensity of the sensor due to environmental factors.According to the analysis results and different application environments,useful suggestions are given.4.The error introduced by the non-normal incidence of light is investigated.Compared with the three sensor modulation structures,when the electric field is along direction the measurement result is more sensitive to the deviation of the incident angle.5.We have developed a three-dimensional electric field direction measurement method.When the intensity of the electric field is constant,we use one crystal and three light paths to measure the direction of the electric field.6.An experimental system was built,the parameters of BGO crystal electric field sensor were calibrated,and preliminary electric field measurement was realized.A good performance of linearity and accuracy is obtained for ac measurements.