Numerical analysis of effective refractive index sensor based on slot micro-ring and Bragg grating

A novel design of a silicon-on-insulator (SOD-based resonator based on slot micro-ring and Bragg gratings is presented. The corrugated Bragg gratings are structured on both sides of slot micro-ring waveguides. The variation of the effective refractive index is detected by monitoring the shift of the spectral of the resonator. The transmission spectrum and field distribution of the sensor structures are simulated using finite-difference time-domain (FDTD) method. With the combination of the Bragg gratings, the measurement range of the sensor significantly increases without the restriction of a free spectral range (FSR). Our proposed sensor design provides a promising candidate for on-chip integration with other silicon photonic element.