Paper
27 February 2015 Optical biosensor based on silicon nanowire ridge waveguide
Rania Gamal, Yehia Ismail, Mohamed A. Swillam
Author Affiliations +
Abstract
Optical biosensors present themselves as an attractive solution for integration with the ever-trending lab-on-a-chip devices. This is due to their small size, CMOS compatibility, and invariance to electromagnetic interference. Despite their many benefits, typical optical biosensors rely on evanescent field detection, where only a small portion of the light interacts with the analyte. We propose to use a silicon nanowire ridge waveguide (SNRW) for optical biosensing. This structure is comprised of an array of silicon nanowires, with the envelope of a ridge, on an insulator substrate. The SNRW maximizes the overlap between the analyte and the incident light wave by introducing voids to the otherwise bulk structure, and strengthens the contribution of the material under test to the overall modal effective index will greatly augment the sensitivity. Additionally, the SNRW provides a fabrication convenience as it covers the entire substrate, ensuring that the etching process would not damage the substrate. FDTD simulations were conducted and showed that the percentage change in the effective index due to a 1% change in the surrounding environment was more than 170 times the amount of change perceived in an evanescent detection based bulk silicon ridge waveguide.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Rania Gamal, Yehia Ismail, and Mohamed A. Swillam "Optical biosensor based on silicon nanowire ridge waveguide", Proc. SPIE 9371, Photonic and Phononic Properties of Engineered Nanostructures V, 93711U (27 February 2015); https://doi.org/10.1117/12.2078398
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Cited by 2 scholarly publications.
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KEYWORDS
Waveguides

Silicon

Nanowires

Refractive index

Optical biosensors

Environmental sensing

Sensors

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