title: Three-dimensional subwavelength imaging by a photonic-crystal flat lens using negative refraction at microwave frequencies.
abstract: We experimentally demonstrate subwavelength resolution imaging at microwave frequencies by a three-dimensional (3D) photonic-crystal flat lens using full 3D negative refraction. The photonic crystal was fabricated in a layer-by-layer process. A subwavelength pinhole source and a dipole detector were employed for the measurement. By point-by-point scanning, we obtained the image of the pinhole source shown in both amplitude and phase, which demonstrated the imaging mechanism and subwavelength feature size in all three dimensions. An image of two pinhole sources with subwavelength spacing showed two resolved spots, which further verified subwavelength resolution.
authors.affiliation: Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716, USA.
authors.forename: Zhaolin
authors.initials: Z
authors.lastname: Lu
authors.forename: Janusz A
authors.initials: JA
authors.lastname: Murakowski
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Schuetz
authors.forename: Shouyuan
authors.initials: S
authors.lastname: Shi
authors.forename: Garrett J
authors.initials: GJ
authors.lastname: Schneider
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Prather