Refractive Index Biosensor Using Surface Plasmon Polariton

• Main Authors: Shao-hsi Lu, 呂紹熙
• Other Authors: Shih-hsiang Hsu
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/17756081134465863649

碩士 === 國立臺灣科技大學 === 電子工程系 === 101 === Surface plasmon resonance (SPR) is a highly sensitive technique to detect small perturbation in structures or composition by utilizing interaction between the thin metal layer and analyte under condition for excitation on surface plasmon. To achieve condition for excitation on surface plasmon, several methods have been proposed and among those prism-coupling and waveguide-coupling are two main approaches. Although the structure of prism-coupling is simpler than waveguide-coupling, the bulk of prism limits its potential for integrating on a compact biosensor and promotes the motivation to choose waveguide-coupling. To make photonic device integrated on a chip, silicon-on-insulator technology provides a good choice due to its fully compatible process with standard process of complementary metal-oxide-semiconductor (CMOS), which allows a silicon waveguide to be fabricated on a submicron scale to fulfill photonic integrated circuit on a miniature. Besides, the large refractive index difference between silicon dioxide and silicon layers further reduce the device size to form silicon wire waveguide, a good platform accompanying with metal to observe interaction between surface plasmon resonance with analyte. In this thesis, the simulation of hybrid plasmonic waveguides was demonstrated to interfere the waveguide mode in silicon wire waveguide with surface plasmon polariton generated at interface of aluminum (Al). In order to be a sensitive probe for biosensing, an optimization on device structure is necessary on the aluminum thickness, silicon dioxide layer, and silicon wire waveguide width. Simulation results demonstrated sensitivity can be up to 3700 dB/RIU to analyte, giving a good example to apply on biosensing.