Research On Key Technology In MEMS Micro-ring Resonator Sensing For Acceleration Detection

MOEMS is a new technology system which developed in the MEMS technology inrecent years. The MOEMS devices have highly integrated and multi-functional integrationcompared to traditional Micro electro-mechanical devices. MOEMS have become one of themost popular technology systems of the world. The micro-ring resonator depend on itsoutstanding optical properties, reliable stability and high sensitivity, have become one of newways to build novel MOEMS devices.According to the force-optics coupling effect and the stress birefringence effect in themicro-nano scale of the micro-ring resonator, we researched the acceleration sensingapplication of the sensor unit in this paper, which composed of micro-ring resonator couplingsystem and micro-cantilever. The sensing performance is mainly determined by the opticalproperties of the micro-ring resonator, so we conducted in-depth study of the coupling systemin this paper. We also designed the micro-cantilever and conducted a preliminary study for itspreparation process.The optical properties of the micro-ring resonator is researched and a kind of cantilevermicro-accelerometer based on MEMS micro-ring resonator is designed either. The sensortheory model is established by force-optical coupling effect and stress birefringence effectprinciple, and analyzed the relationship between the sensor unit parameters and sensitivity ofthe sensor.Based on effective index method and finite difference time domain method (FDTD),optical properties simulation was carried out for different parameters micro-ring resonatorcoupling system with SOI material. And the coupling system was optimized by previousexperience in the design. Also the cantilever structure was optimal designed based on thefinite element analysis method (ANSYS) and ultimately put forward practical design.According to the final design, we achieved two batches of the structure preparation by MEMS process and mainly introduced the process of the system that contain coupling gratingstructure and discussed the process of the cantilever preparation. Applying Narrow linewidth(30GHz) continuous tunable laser as light source and New Focus 25 GHz photodetector assignal receiver in the test process. Coupling system test platforms were built for end couplingmethod and the plane coupling method respectively. It was found that the vertical couplinggrating can achieve high efficient coupling between the fiber and the system, theexperimental results show: the micro-ring resonator quality factor up to 9·104and the theorysensitivity of the acceleration sensor up to 35.4 mv/g. It provide a solid foundation for therealization of highly sensitive micro-accelerometer.