Half-Wave Voltage Controllable Optical Voltage Sensor with Arbitrary Electric Field Direction Modulation

An optical voltage sensor with an arbitrary-electrical-field-direction-modulation mode is proposed to increase the half-wave voltage without bringing additional stress and birefringence. The mode is realized by heterogeneous electrodes arranged in a center-symmetric way, and generate an electrical field with a direction at an arbitrary angle to the light propagation direction. The finite element method and coupling wave theory are used to design and optimize the electrodes and field distribution. The experimental results show that heterogeneous electrodes and arbitrary electric field direction modulation mode is able to effectively regulate the Sensor's half-wave voltage and sensitivity, without degrading the accuracy and linearity. Compared to solid voltage divider method, this modulation mode almost do not generate additional temperature drift or measurement errors caused by birefringence, but have more simple structure, less drift and higher precision.