Electro-optic/Magneto-optic Energy Coupling Method And Device Preparation Of Micro Optical Waveguide Electric Field/Current Sensor

Smart grid needs full-time,global,comprehensive and real-time perception of the operation status information of key equipment and nodes,so as to provide decision-making basis for health evaluation,safety early warning,fault location and emergency disposal.In recent years,domestic and foreign countries have successively put forward the development strategies of intelligent power equipment and transparent power grid,and also put forward clear requirements for the advanced sensor technology of power grid.The low-power,miniaturized and intelligent sensing technology is the basic support and core link to realize the ubiquitous sensing of information in Smart Grid.As the most critical physical quantity in the power grid,electric field and current are not only important monitoring objects in power equipment,but also important sensing quantities in network nodes and lines.To realize the comprehensive sensing of electric field and current,it is urgent to develop advanced chip sensing methods and technologies.At present,with the development of optical fiber technology,optical electric field/current sensor has become a major trend of power grid monitoring.Its optical fiber transmission and electronic information are easy to be combined with smart grid,but there is a lack of suitable miniaturization technology and methods.Therefore,striving to break through the bottleneck of miniaturization and high-precision optical electric field/current sensor,and studying the electro-optic/magneto-optic energy coupling mode and sensor preparation method of new integrated electric field/current sensor is of great significance to support the in-depth perception of power grid information in the construction of smart grid.Based on the electro-optic effect,magnetothermal effect,magneto-optic nonreciprocal phase shift effect and evanescent field sensing principle,the electro-optic/magneto-optic energy coupling mechanism of micro optical waveguide electric field/current sensor is proposed,and the coupling principle and structure of the following four micro sensors are studied through mathematical models:micro electric field sensors based on electro-optic polymers and micro ring resonators Micro current sensor based on superparamagnetic Fe₃O₄ nanoparticles and micro ring resonator,micro electric field sensor based on electro-optic polymer and double-ring assisted Mach Zehnder interferometer,and micro current sensor based on cerium doped yttrium iron garnet magneto-optic film and double-ring assisted Mach Zehnder interferometer.Based on the finite difference time domain method and finite element method,the physical models of micro electric field/current sensor based on micro ring resonator and micro electric field/current sensor based on double-ring assisted Mach Zehnder interferometer are built.Through simulation and analysis,the optical waveguide structure,key parameters and electro-optic/magneto-optic energy coupling of micro electric field/current sensor are designed.The influence mechanism of main structural parameters on the performance of the sensor is studied,and the key structures and parameter optimization indexes of the electric field/current sensor under the optimal coupling state are obtained.Based on the simulation and optimization results of the sensor,the micro fabrication technology and process parameters of the device are studied,and a micro electric field/current sensor based on silicon based micro ring resonator is designed and fabricated.An electric field/current sensing test platform is built in the laboratory to test the sensing characteristics of the micro electric field/current sensor,study the basic characteristics of the micro electric field/current sensor,such as linearity,sensitivity,measurement range and quality factor,and optimize the performance of the micro current sensor by changing the radius of the micro ring.Based on the optimization results of the simulation model,the appropriate micromachining materials,steps and process parameters are designed,and the micro electric field/current sensor based on double-ring assisted Mach Zehnder interferometer is prepared.The electric field/current sensing test platform is built to test the sensing characteristics of the micro electric field/current sensor,and study the input-output characteristics,time-domain response characteristics and frequency response characteristics of the micro electric field/current sensor.Furthermore,a temperature test platform is built to study the temperature stability of micro electric field sensor.The research results of this paper strive to promote the development of low-power,chip based micro electric field and current sensors,provide precursor technology for the high integration of chip based sensing integrated micro system and power grid equipment,and comprehensively support the sustainable development of electric field and current ubiquitous sensing methods and technologies in smart grid.