Vertical silicon nanowire-based racetrack resonator optical sensor

Abstract

We propose a highly sensitive optical sensor which is built from silicon nanowires. The silicon nanowires are arranged to form a ring resonator. The silicon nanowires cladding and voids are filled with the analyte. The sensor has a small footprint of 16 μm × 16.5 μm. The insertion loss of the sensor is only 0.4 dB, while it is characterized by its high sensitivity of 430 nm/RIU. As a biosensor, our device showed a 100 nm/RIU sensitivity when a thin biolayer of 10 nm thickness is attached to the silicon nanowire structures.