abstract
- We demonstrate Mach-Zehnder interferometer and ring resonator evanescent field sensors fabricated on the silicon-on-insulator material platform. These devices exploit the strong evanescent field of the transverse magnetic mode of a high index contrast, submicron dimension waveguide to obtain strong interaction of the guided mode with biomolecules adsorbed to the waveguide surface. We utilize the extremely small bend radius achievable with silicon photonic wire waveguides to fabricate spiral and folded waveguide sensors that maintain the high sensitivity of a long waveguide, while providing compact footprint. These devices offer a suitable geometry for the development of sensor arrays and provide compatibility with commercial spotting functionalization systems. We demonstrate sensors containing waveguides of up to 5.5 mm length that are contained within a 150 mum × 150 mum area.