In-situ Microplastic Detection Sensor based on Cascaded Microring Resonators

Microplastics in the oceans is a growing concern in the recent years as it directly affects the marine life and indirectly affects the health of humans as well. Identifying these microplastics is a laborious process and often involves the bulky equipment for analysis. In this work, we proposed an in-situ microplastics detection sensor by employing the Ge on Si rib waveguide microring resonators as a core sensing element which are arranged in cascaded manner to achieve the Vernier effect thus useful for high sensitivity analysis in near and mid IR regions where the absorption spectra of most of the plastics falls under. As a Mid IR source, Optical Network Analyzer (ONA) has been used which generates source light (in Mid IR) and simulated in Lumerical Interconnect software. Finally, mode profiles, effective indices of waveguides and transmission spectrum, Free Spectral range (FSR) of PIC circuit has been calculated and presented. The simulations have been performed in Lumerical Mode for modal analysis, Lumerical FDTD for compact model generation and S-parameters extraction and Lumerical Interconnect for circuit level simulation.