A New Design for Enhancing Highly Sensitive Interferometer Biosensor Using a Silicon Rib Waveguide

In this paper, we have proposed a new design, to enhance and simulate a Highly Sensitive Mach-Zehnder Interferometer (MZI) Biochemical sensing platform using a Silicon Rib Waveguide. We considered two different MZI configurations: the first one with an S-bend & Y-junction and the second with an angular Y-junction. We determined the critical cut-off radius and the critical cut-off angle for the S-bend & Y-junction and the angular Y-junction configurations respectively. Based on the analyses of the evanescent field intensity, the mode polarization and cross section dimensions of the Silicon Rib waveguide are optimized using beam propagation method. The critical parameters of the design are calculated to ensure minimal optical losses and a new sensitivity value of 308 dB/RIU with a detection limit of 10-7, which shows the ability of the structure to produce biosensor.