Analysis of optical sensing behavior of a novel optical bean-shaped resonator biosensor integrated with MZI configuration

Abstract

A novel optical bean-shaped resonator (BR) biosensor integrated with Mach–Zehnder Interferometer structure based on a silicon-on-isolator platform has been proposed and investigated theoretically and numerically. By characterizing and optimizing the structure, our bean-shaped device exhibits a high extinction ratio over 50 dB and a high Q factor of about 5.46 × 10⁴ in a wide wavelength span. The quasi-free spectral range (FSR) is about 469 nm. The sensitivity of 688.6 nm/refractive index unit (RIU) is achieved for bulk changes of refractive index and the detection range varies from 10⁻⁶ to 0.689 RIU. More complex bean-shaped structures can also be cascaded by adding more bending waveguides in BR to obtain wider quasi-FSR range.

Keywords:

• integrated optics devices
• optical sensing and sensors
• Ring resonator
• Vernier effect
• bean-shaped resonator biosensor

Funding

This work was sponsored in part by the National Natural Science Foundation of China [grant number 61107088], [grant number 61107061]; Program for New Century Excellent Talents in University [grant number NCET-12-0092]; the Scientific Research Foundation for the Returned Overseas Chinese Scholars of State Education Ministry [grant number 2012GJ002]; Project of international sci-tech cooperation and exchange research of Sichuan Province [grant number 2012HH0001].