The design, modeling, fabrication, and experimental measurements on optical nanobeam cavities that change resonant frequency in response to changes in the
refractive index of the surrounding environment are presented. Nanobeam cavities based on Silicon-On-Insulator (SOI) that work at telecommunication
wavelengths (1550 nm) provide an ideal platform for label-free sensing, due to their features of high resonance Q-factors, high sensitivity and capability for integration with silicon CMOS.
We present the design modelling and fabrication of Silicon-On-Insulator (SOI) nanobeam cavities that are immersed in
a microfluidic system for refractive index sensing. The device has sensitivity value of greater than 200 nm/RIU with a
Q-factor more than 20 000 in water. It was fabricated on a SOI platform and working at telecom wavelengths. The use
of the SOI platform also offers further possibilities of integration with CMOS technologies.