Study on Electric Field Sensing Performance of Barium Titanate Optical Waveguide

At present, some basic progress has been achieved in measuring or sensing weak radiation electric field by using sensors. However, the sensitivity of sensors is still affected by the limitation of materials, so it is urgent to study a sensor that can measure weak intensity. In this paper, a Barium titanate crystal thin film waveguide electric field sensor with very high electro-optic coefficient ($r_{51}=r_{42}$) is studied. We find that the dynamic sensitivity of the electrooptic sensor is independent of the sensing length, but on the birefringence of the Barium titanate crystal thin film and the light-microwave velocity mismatch (VMM).