High-Q ultrasensitive integrated photonic sensors based on slot-ring resonator on a 3C-SiC-on-insulator platform

We demonstrate, to the best of our knowledge, the first high- Q silicon carbide (SiC) integrated photonic sensor based on slot-ring resonators on a 3C-SiC-on-insulator (SiCOI) platform. We experimentally demonstrate an intrinsic Q of 17,400 at around 1310 nm wavelength for a slot-ring resonator with 40 µm radius with water cladding. By applying different concentrations of a sodium chloride (NaCl) solution that covers the devices, measured bulk sensitivities of 264–300 nm/RIU (refractive index unit) are achieved in the slot-ring resonator with a 400–450 nm rail width and a 100–200 nm slot width. The device performance for biomolecular layer sensing (BMLS) is proved by the detection of the cardiac biomarker troponin with 248–322 pm/nm surface sensitivity. The reported slot-ring resonators can be of great interest for diverse sensing applications from visible to infrared wavelengths.