Optimization of periodic composite structures for sub-wavelength focusing
| dc.creator | Dobson, David C. | |
| dc.creator | Simeonova, Lyubima B. | |
| dc.date | 2008-03-10 | |
| dc.date.accessioned | 2026-07-07T09:25:58Z | |
| dc.date.available | 2026-07-07T09:25:58Z | |
| dc.description | Recently, there has been plenty of work in designing and fabricating materials with an effective negative refractive index. Veselago realized that a slab of material with a refractive index of -1 would act as a lens. Pendry suggested that the Veselago lens would act as a superlens, providing a perfect image of an object in contrast to conventional lenses which are only able to focus a point source to an image having a diameter of the order of the wavelength of the incident field. Recent work has shown that similar focusing effects can be obtained with certain slabs of ``conventional'' periodic composite materials: photonic crystals. The present work seeks to answer the question of what periodic dielectric composite medium (described by dielectric coefficient with positive real part) gives an optimal image of a point source. An optimization problem is formulated and it is shown that a solution exists provided the medium has small absorption. Solutions are characterized by an adjoint-state gradient condition, and several numerical examples illustrate both the plausibility of this design approach, and the possibility of obtaining smaller image spot sizes than with typical photonic crystals. | |
| dc.description | 15 pages, 6 figures | |
| dc.identifier | https://arxiv.org/abs/0803.1474 | |
| dc.identifier | http://arxiv.org/abs/0803.1474 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/156592 | |
| dc.subject | Optimization and Control | |
| dc.subject | 78-02, 35J20, 49S05 | |
| dc.title | Optimization of periodic composite structures for sub-wavelength focusing | |
| dc.type | text |