High sensitive silicon optical index sensor based on Ring-assisted Mach-Zehnder interferometer

This paper demonstrated the design and fabrication of Ring-assisted Mach-Zehnder interferometer (RA-MZI) based optical sensor. The measurement result shows a free spectrum range (FSR) of 5 nm and a highest Q-factor of 2000. Finite difference time domain (FDTD) simulation result shows a sensitivity of 137.5 nm/RIU for sensing ambient refractive index (RI) change.