Wavelength Division Multiplexing Multi-Channel Sensing Circuit Using Si on Insulator Platform

Multi-channel sensing circuit utilizing wavelength division multiplexing is proposed using silicon on insulator platform. The circuit consists of four sections that can be decomposed into a bandpass (BP) filter and a sensing ring resonator (RR). Four different wavelength bands are allocated to four sections by the BP filter so that each signal from four RRs could be distinguished on a single spectrum. In this scheme, multiple sensing RRs can be measured at once with a conventional fiber alignment system including a single light source and detector. Our proposal also realizes the reduction of measurement equipment size and cost, and improves fiber usage efficiencies because multiple sensing signals are superimposed on a spectrum. We fabricated and verified that the designed sensing circuit operated as expected, and four sensing RRs worked as designed by a single measurement. This concept enhances the potential of multiple detections of various substances on a chip