title: Field concentration by exciting surface defect modes.
abstract: We propose a design for patterned metal-coated surfaces allowing efficient broadband coupling of radiation to a fully localized surface cavity mode, resulting in a zero-focal-length concentrator. This finite structure exploits the interplay of a defect mode cavity with a coupling grating and is investigated through the modal expansion method and finite-difference time domain calculations.
authors.affiliation: Thales Research and Technology France, RD 128, Palaiseau 91767, France, and Matériaux et Phénomènes Quantiques, Université Paris 7, 2, Place Jussieu, 75251 Paris, France. mathieu.carras@thalesgroup.com
authors.forename: Mathieu
authors.initials: M
authors.lastname: Carras
authors.forename: Alfredo
authors.initials: A
authors.lastname: De Rossi