C-band Operating Plasmonic Sensor with High Q-factor/Figure of Merit (FOM) Based on Silicon Nano-Ring

Abstract In this paper, we take advantage of the high refractive index property of silicon to design a practical and sensitive plasmonic sensor on a Photonic Integrated Circuit (PIC) platform. It has been shown that by employing a concentric silicon nano-ring with a hexagonal plasmonic cavity, a label-free refractive index sensor with sensitivity as high as 1124 nm/RIU, a Q-factor of 307 and an FOM of 234 RIU− 1 can be achieved with optimal structural parameters. In addition, the resonance mode of the hexagonal cavity with Si nano-ring (HCS) sensor can be adjusted to operate in the c-band, which is a highly desirable wavelength range in terms of compatibility with devices in PIC technology.