Development of silicon photonics dual disks resonators as chemical sensors

This paper reports a novel whispering gallery mode photonic dual-disk resonator (DDR) with enhanced quality factors. The second disk with the same dimension as the primary disk enhances the coupling efficiency of the bus waveguide and the disk resonators. The compact disk design brings the possibilities of smaller device dimension and large integration of optical circuits on a chip. The measured result shows 25 nm of free spectrum range (FSR) and the data has a good agreement with three dimensional (3-D) finite difference time domain (FDTD) simulation results. Chemical index sensing is demonstrated with a sensing opening hole filled with droplet of different liquid cladding.