Broadband Integrated Optical Waveguide Current Sensor Based on a Magneto-Optical Thin Film

Broadband transient current measurement is a basic research method in many engineering fields. Optical integrated current sensor has the advantages of small size, anti electromagnetic interference and high precision, which has become a major trend of current monitoring. However, the existing optical current sensing methods have great challenges in broadband, wide amplitude and volume miniaturization. In this paper, a new high-performance magneto-optical energy coupling sensing method based on silicon photons and magneto-optical materials is studied, and an integrated optical waveguide current sensor based on a magneto-optical thin film and a double-ring assisted Mach–Zehnder interferometer is proposed. The energy coupling between the micro-ring resonator and the magneto-optical thin film is achieved through the magneto-optical nonreciprocity effect, and the current information is obtained by modulating the output light intensity with the Mach–Zehnder interferometer. The experimental results show that the sensor has a good linearity and a large dynamic measurement range. The measurement frequency range is from10 Hz to 13.56 MHz, and the sensitivity is 2.183 mV/A. This work seeks to promote the development of optical broadband current sensors on chips.