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An Optimization Framework for Silicon Photonic Evanescent-Field Biosensors Using Sub-Wavelength Gratings Puumala, Lauren S.; Grist, Samantha M.; Wickremasinghe, Kithmin; Al-Qadasi, Mohammed A.; Chowdhury, Sheri Jahan; Liu, Yifei; Mitchell, Matthew; Chrostowski, Lukas; Shekhar, Sudip; Cheung, Karen C.

Abstract

Silicon photonic (SiP) evanescent-field biosensors aim to combine the information-rich readouts offered by lab-scale diagnostics, at a significantly lower cost, and with the portability and rapid time to result offered by paper-based assays. While SiP biosensors fabricated with conventional strip waveguides can offer good sensitivity for label-free detection in some applications, there is still opportunity for improvement. Efforts have been made to design higher-sensitivity SiP sensors with alternative waveguide geometries, including sub-wavelength gratings (SWGs). However, SWG-based devices are fragile and prone to damage, limiting their suitability for scalable and portable sensing. Here, we investigate SiP microring resonator sensors designed with SWG waveguides that contain a “fishbone” and highlight the improved robustness offered by this design. We present a framework for optimizing fishbone-style SWG waveguide geometries based on numerical simulations, then experimentally measure the performance of ring resonator sensors fabricated with the optimized waveguides, targeting operation in the O-band and C-band. For the O-band and C-band devices, we report bulk sensitivities up to 349 nm/RIU and 438 nm/RIU, respectively, and intrinsic limits of detection as low as 5.1 × 10−⁴ RIU and 7.1 × 10−⁴ RIU, respectively. This performance is comparable to the state of the art in SWG-based sensors, positioning fishbone SWG resonators as an attractive, more robust, alternative to conventional SWG designs.

Item Metadata

Title
An Optimization Framework for Silicon Photonic Evanescent-Field Biosensors Using Sub-Wavelength Gratings
Creator
Puumala, Lauren S.; Grist, Samantha M.; Wickremasinghe, Kithmin; Al-Qadasi, Mohammed A.; Chowdhury, Sheri Jahan; Liu, Yifei; Mitchell, Matthew; Chrostowski, Lukas; Shekhar, Sudip; Cheung, Karen C.
Contributor
University of British Columbia. Centre for Blood Research; The Stewart Blusson Quantum Matter Institute
Publisher
Multidisciplinary Digital Publishing Institute
Date Issued
2022-10-08
Description
Silicon photonic (SiP) evanescent-field biosensors aim to combine the information-rich readouts offered by lab-scale diagnostics, at a significantly lower cost, and with the portability and rapid time to result offered by paper-based assays. While SiP biosensors fabricated with conventional strip waveguides can offer good sensitivity for label-free detection in some applications, there is still opportunity for improvement. Efforts have been made to design higher-sensitivity SiP sensors with alternative waveguide geometries, including sub-wavelength gratings (SWGs). However, SWG-based devices are fragile and prone to damage, limiting their suitability for scalable and portable sensing. Here, we investigate SiP microring resonator sensors designed with SWG waveguides that contain a “fishbone” and highlight the improved robustness offered by this design. We present a framework for optimizing fishbone-style SWG waveguide geometries based on numerical simulations, then experimentally measure the performance of ring resonator sensors fabricated with the optimized waveguides, targeting operation in the O-band and C-band. For the O-band and C-band devices, we report bulk sensitivities up to 349 nm/RIU and 438 nm/RIU, respectively, and intrinsic limits of detection as low as 5.1 × 10−⁴ RIU and 7.1 × 10−⁴ RIU, respectively. This performance is comparable to the state of the art in SWG-based sensors, positioning fishbone SWG resonators as an attractive, more robust, alternative to conventional SWG designs.
Subject
silicon photonics; evanescent field biosensor; SOI biosensor; ring resonator; fishbone sub-wavelength grating waveguide; sub-wavelength grating waveguide; SWG-assist waveguide; bridged SWG waveguide; microfluidics
Genre
Article
Type
Text
Language
eng
Date Available
2024-12-17
Provider
Vancouver : University of British Columbia Library
Rights
CC BY 4.0
DOI
10.14288/1.0447522
URI
http://hdl.handle.net/2429/89896
Affiliation
Applied Science, Faculty of; Other UBC; Non UBC; Biomedical Engineering, School of; Electrical and Computer Engineering, Department of
Citation
Biosensors 12 (10): 840 (2022)
Publisher DOI
10.3390/bios12100840
Peer Review Status
Reviewed
Scholarly Level
Faculty
Rights URI
https://creativecommons.org/licenses/by/4.0/
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CC BY 4.0