Research On High-sensitivity Cascaded Double-Ring And Biological Detection Technology In SOI

Nowadays people value more health and environment in their life as the rapid development of information technology. It is very essential to design new sensors used for environmental monitoring, but also in the field of medical diagnosis, food industry, life science and so on. The integrated waveguide biosensor with its high sensitivity, low cost and portability, will play an important role in the future.This paper is based on the research of cascaded double-ring waveguide sensor in our lab, and apply it in the biological detection to test its performance.We firstly introduced the basic theory and structure parameters of an optical ring resonant cavity, and then analyzed the propagation and coupling property of the single ring resonant cavity with TMM(transfer matrix method).We also studied the fabrication process of the sensor in silicon-on-insulator platform, including photolithography, development, etch and so on. In addition, we build a precise optical coupling test platform and introduce the relevant method to couple the light into the waveguide.Finally, we made a research on the biosense performance of the sensor. Firstly, the surface of the sensor was modified by PDDA-PSS polyelectrolyte complex and it detected different concentration of biotin through electrostatic adherence successfully. Besides, we experimented to make the biotin immobilized on the surface covalently. It proved to combine streptavidin in a biospecific interaction way.