User login

A silicon photonic biosensor using phase-shifted Bragg gratings in slot waveguide

Publication Type:

Journal Article


Journal Biophotonics, Volume 6, Issue 10, p.821--828 (2013)



biosensor; silicon photonics; slot waveguide; Bragg grating; microfluidics; limit of detection


We present a novel silicon photonic biosensor using phase-shifted Bragg gratings in a slot waveguide. The optical field is concentrated inside the slot region, leading to efficient light-matter interaction. The Bragg gratings are formed with sidewall corrugations on the outside of the waveguide, and a phase shift is introduced to create a sharp resonant peak within the stop band. We experimentally demonstrate a high sensitivity of 340 nm/RIU measured in salt solutions and a high quality factor of 1.5 × 10^{4}, enabling a low intrinsic limit of detection of 3 × 10^{–4} RIU. Furthermore, the silicon device was fabricated by a CMOS foundry, facilitating high-volume and low-cost production. Finally, we demonstrate the device's ability to interrogate specific biomolecular interactions, resulting in the first of its kind label-free biosensor. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)


This is the pre-peer reviewed version of the following article: Wang, X., Flueckiger, J., Schmidt, S., Grist, S., Fard, S. T., Kirk, J., Doerfler, M., Cheung, K. C., Ratner, D. M. and Chrostowski, L. (2013), A silicon photonic biosensor using phase-shifted Bragg gratings in slot waveguide. J. Biophoton.. doi: 10.1002/jbio.201300012, which has been published in final form at [].

Full Text:

Faculty Member(s): 
Faculty Member(s): 
Research Area(s): 
Biomedical Engineering
Research Area(s): 
Sensors and Actuators
Research Area(s): 
Photonics and Optics