Integrated Optical Double Ring Resonators with MEMS for Pressure and Acceleration Sensing

Abstract

Silicon Photonics has become a signi ficant area of research in last three decades because of its high speed operation, low power consumption and the most important feature, resistant to electro-magnetic interferences. Mi- cro ring resonators are an important part of Photonic Integrated circuits. The advantages it posses like compactness, strong optical enhancement and wavelength selectivity. It does not require any kind of gratings for looping backwards. These features make ring resonator reliable for applications like sensing, filtering, optical buffering, loss measurements and non-linear effects. This thesis consists of the design and analysis of double micro ring resonator of radius 5 m and 4 m for the sensing of differential pressure sensor and ac- celerometer using integrated Optical MEMS. The single micro ring resonator has been analyzed thoroughly detailing its characteristics and properties. All the simulations are performed on MATLAB R2017b. To achieve higher Q- factor, higher sensitivity, higher FSR than that of a Single ring, the Double Ring Resonator is designed and analyzed. The Vernier effect is responsi- ble for higher FSR in Double Ring. A detailed study on Vernier effect on Double Ring is done followed by the characteristics and properties of Double ring resonator. To design the mechanical sensors, the role of Optical MEMS is very crucial. The micro-cantilever beam is studied w.r.t the position of straight waveguide and ring and stress distribution in each case is plotted. The analysis of micro-cantilever beam and ring resonator is done using Finite Element Method (FEM). The sensors designed in this thesis are differential pressure sensor and accelerometer. The differential pressure sensor achieved a sensitivity of 15:54pm=kPa whereas the accelerometer was designed using a non-uniform cantilever beam. Here two con figrations were proposed in order to acheive higher Dynamic Range and better sensitivity. A step-like proof- mass is used in the second con figration. The first con figuration achieved a sensitivity of 26:6pm=g and Dynamic range of 4g and the second con gu- ration achieved a sensitivity of 30:75pm=g and Dynamic range of 10g.