Performance evaluation of a bilayer SPR-based fiber optic RI sensor with TiO2 using FDTD solutions

• Main Authors: Al-Qazwini, Yusser, Muhammad Noor, Ahmad Shukri, Yadav, T. K., Yaacob, Mohd. Hanif, Harun, Sulaiman Wadi, Mahdi, Mohd Adzir
• Format: Article
• Published: SpringerOpen 2014
• Online Access: http://psasir.upm.edu.my/id/eprint/34875/; http://link.springer.com/article/10.1007/s13320-014-0207-y

We proposed a new bilayer surface plasmon resonance-based fiber-optic refractive index sensor with silver and an over-layer of TiO2. We numerically investigated the optimal thickness of TiO2 over-layer in the proposed sensor and compared its performance to that based on typical bimetallic layers of silver-and-gold in the aqueous media using finite-difference time domain approach. We show that the use of TiO2 over-layer greatly improves the sensor performance in terms of sensitivity and signal-to-noise ratio compared to that with gold as the over-layer. Not only does the TiO2 over-layer offer a cost-effective alternative to gold for overcoming the oxidation problem, but also it allows resonance wavelength-tunability.