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Light trapping beyond the 4n^2 limit in thin waveguides

Munday, Jeremy N. and Callahan, Dennis M. and Atwater, Harry A. (2012) Light trapping beyond the 4n^2 limit in thin waveguides. Applied Physics Letters, 100 (12). Art. No. 121121. ISSN 0003-6951. doi:10.1063/1.3695156.

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We describe a method for determining the maximum absorption enhancement in thin film waveguides based on optical dispersion relations. For thin film structures that support one, well-confined guided mode, we find that the absorption enhancement can surpass the traditional limit of 4n^2 when the propagation constant is large and/or the modal group velocity is small compared to the bulk value. We use this relationship as a guide to predicting structures that can exceed the 4n^2 light trapping limit, such as plasmonic and slot waveguides. Finally, we calculate the overall absorption for both single and multimode waveguides, and show examples of absorption enhancements in excess of 4n^2 for both cases.

Item Type:Article
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URLURL TypeDescription DOIArticle
Atwater, Harry A.0000-0001-9435-0201
Additional Information:© 2012 American Institute of Physics. Received 6 January 2012; accepted 29 February 2012; published online 23 March 2012. The authors acknowledge helpful discussions with E. Schiff, P. Saeta, M. Leite, S. Burgos, E. Feigenbaum, E. Kosten, J. Fakonas, D. O’ Carroll, J. Grandidier, V. E. Ferry, and K. Aydin. This work was supported by the Energy Frontier Research Center program of the Office of Science of the Department of Energy under Grant DESC0001293 (J.N.M.) and by Department of Energy under Grant DOE DE-FG02-07ER46405 (D.M.C.).
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0001293
Department of Energy (DOE)DE-FG02-07ER46405
Subject Keywords:optical dispersion, optical films, optical waveguides, plasmonics, radiation pressure
Issue or Number:12
Classification Code:PACS: 42.79.Gn; 42.70.-a
Record Number:CaltechAUTHORS:20120502-075256296
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:31264
Deposited By: Tony Diaz
Deposited On:02 May 2012 17:03
Last Modified:09 Nov 2021 19:48

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