A Bias Controllable Birefringence Modulation Measurement System for Subnanosecond Pulsed Electric Field

Abstract

This article introduces a bias controllable integrated optics electric field measurement system fabricated by LiNbO3 (LN) that can be used for the measurement of 10-kV/m subnanosecond rise time electromagnetic pulse (EMP). Combined with the structure of birefringence modulation (BRM) and the 1550-nm tunable laser, this probe has simple structure measures 1.5 cm $\times 2$ cm $\times4.5$ cm. It realized the set of bias to any value during $2\pi $ with less than 1-nm change of the wavelength of the tunable laser, despite the influence of the environment. Furthermore, an optimal bias automatic feedback controller based on Newton iteration algorithm is constructed to lock the bias at a fixed point. The statistical result (average ± standard deviation) of the bias under controlled is 90.4 ± 0.8°. Calibrated results show that it shows consistent response to the pulse with rise time of 200 ps, and the minimum and maximum measurement amplitude is 0.3 and 45 kV/m, respectively.