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

作者：Wang Xu^*; Flueckiger Jonas; Schmidt Shon; Grist Samantha; Fard Sahba T; Kirk James; Doerfler Matt; Cheung Karen C; Ratner Daniel M; Chrostowski Lukas

来源：Journal of Biophotonics, 2013, 6(10): 821-828.

DOI：10.1002/jbio.201300012

<jats:title>Abstract</jats:title><jats:p>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<jats:sup>4</jats:sup>, enabling a low intrinsic limit of detection of 3 × 10<jats:sup>–4</jats:sup> 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.

• 出版日期2013-10