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Surface-wave-enabled darkfield aperture for background suppression during weak signal detection

Zheng, Guoan and Cui, Xiquan and Yang, Changhuei (2010) Surface-wave-enabled darkfield aperture for background suppression during weak signal detection. Proceedings of the National Academy of Sciences of the United States of America, 107 (20). pp. 9043-9048. ISSN 0027-8424. PMCID PMC2889114.

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Sensitive optical signal detection can often be confounded by the presence of a significant background, and, as such, predetection background suppression is substantively important for weak signal detection. In this paper, we present a novel optical structure design, termed surface-wave-enabled darkfield aperture (SWEDA), which can be directly incorporated onto optical sensors to accomplish predetection background suppression. This SWEDA structure consists of a central hole and a set of groove pattern that channels incident light to the central hole via surface plasmon wave and surface-scattered wave coupling. We show that the surface wave component can mutually cancel the direct transmission component, resulting in near-zero net transmission under uniform normal incidence illumination. Here, we report the implementation of two SWEDA structures. The first structure, circular-groove-based SWEDA, is able to provide polarization-independent suppression of uniform illumination with a suppression factor of 1230. The second structure, linear-groove-based SWEDA, is able to provide a suppression factor of 5080 for transverse-magnetic wave and can serve as a highly compact (5.5 micrometer length) polarization sensor (the measured transmission ratio of two orthogonal polarizations is 6100). Because the exact destructive interference balance is highly delicate and can be easily disrupted by the nonuniformity of the localized light field or light field deviation from normal incidence, the SWEDA can therefore be used to suppress a bright background and allow for sensitive darkfield sensing and imaging (observed image contrast enhancement of 27 dB for the first SWEDA).

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URLURL TypeDescription DOIArticle CentralArticle Information
Yang, Changhuei0000-0001-8791-0354
Additional Information:© 2010 National Academy of Sciences. Freely available online through the PNAS open access option. Edited by F. Javier García de Abajo, University of the Basque Country, Spain, and accepted by the Editorial Board March 17, 2010 (received for review November 2, 2009). Published online before print May 3, 2010. We are grateful for the constructive discussions with and the generous help from Professor Axel Scherer (Caltech); Dr. Xin Heng (BioRad); and Dr. Meng Cui, Dr. Emily McDowell, Ms. Yingmin Wang, Dr. Jigang Wu, Mr. Jian Ren, and Mr. Lap Man Lee (Caltech). We appreciate the assistance of Kavli Nanoscience Institute at Caltech. This work is funded by the Wallace Coulter Foundation, the National Science Foundation Career Award BES-0547657, and the National Institutes of Health Grant R21EB008867-01. Author contributions: G.Z. and C.Y. designed research; G.Z. performed research; G.Z. analyzed data; and G.Z., X.C., and C.Y. wrote the paper. The authors declare no conflict of interest. This article is a PNAS Direct Submission. F.D. is a guest editor invited by the Editorial Board. This article contains supporting information online at
Group:Kavli Nanoscience Institute
Funding AgencyGrant Number
Wallace Coulter FoundationUNSPECIFIED
Subject Keywords:surface plasmon; nanophotonics; cell imaging; biological and chemical sensing
Issue or Number:20
PubMed Central ID:PMC2889114
Record Number:CaltechAUTHORS:20100607-133514272
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Official Citation:Zheng, G., X. Cui, et al. (2010). "Surface-wave-enabled darkfield aperture for background suppression during weak signal detection." Proceedings of the National Academy of Sciences 107(20): 9043-9048.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:18585
Deposited By: Tony Diaz
Deposited On:15 Jul 2010 20:33
Last Modified:09 Mar 2020 13:19

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