Reflective miniature optical electric field sensor

The theoretical sensing model of reflective optical electric field sensor based on the Pockels effect was established based on the calculation of Jones matrix, in order to measure the direct current, alternating and transient electric field. The effects of lithium niobate crystal length, crystal cutting type, temperature and external applied stress on the sensing performance of the probe were analyzed. A reflective miniature optical electric field sensor probe, with the size of Φ5 mm×80 mm and the theoretical measurement range of ±439.2 kV/m, was prepared. A sensing system was built to characterize the probe under 10~5000 Hz alternating, direct current and 8.2 GHz to 12.4 GHz high frequency microwave electric field. Results show that the probe performs well in response to electric field in the frequency range of DC-12.4 GHz, with long-time signal drifting no more than 0.08‰, the resolution for at least 3 V/m, and the actual measurement range for 10−3 kV/m to 102 kV/m. This optical electric field sensor can be practical for DC, ms and ns transient electric field monitoring in high-power microwave detection and power systems. © 2021, Zhejiang University Press. All right reserved.