Topic: Broadband super-resolution and energy transport in a metallo dielectric lens
Speaker: Dr. Giuseppe D’Aguanno, Senior Research Associate (NRC), Charles M. Bowden Research Center, U.S. Army, RDECOM
Date & Time: Thursday, April 5, 2007
Place: Room 140 VMC (Chambers Hall)
We present a theoretical analysis of a super-resolving lens based on 1-dimensional metallo-dielectric photonic crystals composed of Ag/GaP multilayers. The lens contains a total of 10 optical skin depths of Ag, yet maintains a normal incidence transmittance of ~50% for propagating waves over the super-resolving wavelength range of 500-650 nm. The individual Ag layers are 22 nm thick and can be readily fabricated in conventional deposition systems. The importance of anti-reflection coatings for the transmission of evanescent and propagating waves is illustrated by comparison to periodic and symmetric structures without the coatings. In addition, the reflection for propagating waves is reduced to ~5% across the super-resolving wavelength band diminishing the interference between the object and the lens. We also study the energy transport during the super-resolution process. In particular we put into evidence the role played respectively by the evanescent and propagative modes. Our analysis shows that the presence of evanescent modes causes strong energy circulation outside the lens. Moreover we discuss the influence of the evanescent modes on the ohmic losses and on the local power transported through the lens.
Dr. Giuseppe D’Aguanno received his PhD in “Applied Electromagnetism and Electro-Physical Sciences” from the University of Rome “La Sapienza” (Italy) in the year 2000. From 2001 to 2003, he has been a research associate with the National Institute for the Physics of Matter (INFM-Italy) and temporary professor at the University of Rome “La Sapienza”. From 1999-2002, he has also been a visiting scholar at Redstone Arsenal (U.S. Army) in close collaboration with the group of the late Dr. Chuck Bowden. From 2003 to 2005, he has been a research physicist for Time Domain Corporation (Huntsville-Alabama). He is currently a National Research Council senior research associate at the Charles M. Bowden Research Facility of the U.S. Army (Redstone Arsenal). His main research interests include nano-structures, photonic crystals, meta-materials, non-hermitian electromagnetic problems, tunneling problems in dispersive and absorbing materials, guided propagation, diffraction and super-resolution, ultra-short pulse propagation in linear and nonlinear materials and dispersion-free propagation, nonlinear interactions in quadratic and cubic materials, Green’s function and density of modes for finite structures. He is coauthor of more than 50 publications in peer reviewed journals and 5 book contributions. Dr. D’Aguanno is a member of the Optical Society of America.
Refreshments will be served at 12:45 PM