Mode Sensitivity Exploration of Silica-Titania Waveguide for Refractive Index Sensing Applications.

In this paper, a novel and cost-effective photonic platform based on silica-titania material is discussed. The silica-titania thin films were grown utilizing the sol-gel dip-coating method and characterized with the help of the prism-insertion technique. Afterwards, the mode sensitivity analysis of the silica-titania ridge waveguide is investigated via the finite element method. Silica-titania waveguide systems are highly attractive due to their ease of development, low fabrication cost, low propagation losses and operation in both visible and near-infrared wavelength ranges. Finally, a ring resonator (RR) sensor device was modelled for refractive index sensing applications, offering a sensitivity of 230 nm/RIU, a figure of merit (FOM) of 418.2 RIU-1, and Q-factor of 2247.5 at the improved geometric parameters. We believe that the abovementioned integrated photonics platform is highly suitable for high-performance and economically reasonable optical sensing devices.