Parallel-Coupled Dual SiOxNy Racetrack Resonators As Biosensors with High Improved Intrinsic Limit of Detection

This study describes a chip-integrated optical biosensor based on dual coupled racetrack resonators. A physical analysis of the device is carried out using conformal transformation and coupled-mode theory. The intrinsic limit of detection is improved by a factor of 100, compared to a conventional single-resonator system, with better dynamic range as well. The proposed sensor could be a promising candidate for analyzing different components of blood samples in medical diagnostics, which is especially important for the early detection of critical cancers, such as prostate cancer.