Fano lineshapes of 'Peak-tracking chip' spatial profiles analyzed with correlation analysis for bioarray imaging and refractive index sensing (Orale)

Autor: Weisheng Yue, Kristelle Bougot-Robin, Xixiang Zhang, Longqin Chen, Henri Benisty, Weijia Wen, Shunbo Li
Přispěvatelé: Institute for Advanced Studies, Hong Kong University of Science and Technology (HKUST), Department of Physics [Hong Kong University of Science and Technology], King Abdullah University of Science and Technology (KAUST), Laboratoire Charles Fabry / Naphel, Laboratoire Charles Fabry (LCF), Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS), Jean-Marc Fédéli
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: Proc. SPIE
SPIE Microtechnologies, Conference on Integrated Photonics-Materials, Devices, and Applications II
SPIE Microtechnologies, Conference on Integrated Photonics-Materials, Devices, and Applications II, Apr 2013, Grenoble, France. pp.UNSP 876703, ⟨10.1117/12.2018316⟩
Integrated Photonics: Materials, Devices, and Applications II
Integrated Photonics: Materials, Devices, and Applications II, Apr 2013, Grenoble, France. pp.876703
Popis: The asymmetric Fano resonance lineshapes, resulting from interference between background and a resonant scattering, is archetypal in resonant waveguide grating (RWG) reflectivity. Resonant profile shift resulting from a change of refractive index (from fluid medium or biomolecules at the chip surface) is classically used to perform label-free sensing. Lineshapes are sometimes sampled at discretized “detuning” values to relax instrumental demands, the highest reflectivity element giving a coarse resonance estimate. A finer extraction, needed to increase sensor sensitivity, can be obtained using a correlation approach, correlating the sensed signal to a zero-shifted reference signal. Fabrication process is presented leading to discrete Fano profiles. Our findings are illustrated with resonance profiles from silicon nitride RWGs operated at visible wavelengths. We recently demonstrated that direct imaging multi-assay RWGs sensing may be rendered more reliable using “chirped” RWG chips, by varying a RWG structure parameter. Then, the spatial reflectivity profiles of tracks composed of RWGs units with slowly varying filling factor (thus slowly varying resonance condition) are measured under monochromatic conditions. Extracting the resonance location using spatial Fano profiles allows multiplex refractive index based sensing. Discretization and sensitivity are discussed both through simulation and experiment for different filling factor variation, here Δf=0.0222 and Δf=0.0089. This scheme based on a “Peak-tracking chip” demonstrates a new technique for bioarray imaging using a simpler set-up that maintains high performance with cheap lenses, with down to Δn=2×10 -5 RIU sensitivity for the highest sampling of Fano lineshapes.
Databáze: OpenAIRE
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