Polarization-dependent bandwidth in low-index plasmonic metamaterials.

We investigate the visible range, less-than-one index bandwidth, n(λ)<1, of an optical metamaterial structure composed of plasmonic gold nanoparticles, and show that it is highly dependent on the polarization of incident light. The full-wave finite element method is used to obtain the spectral characteristics of the structure. We have found spectral bands over which the structure shows the desired low index.

Legacies of the Gerchberg-Saxton algorithm.

To celebrate W. Owen Saxton's 65th birthday, this paper presents some of the impact that the Gerchberg-Saxton algorithm has had over the last 40 years. We explore some of the fundamental concepts underlying the success of the Gerchberg-Saxton algorithm, in the context of how it stimulated many related methods for estimating fields and deepening the understanding of the relationships between complex objects, images and their Fourier transforms.

Selective field localization in random structured media.

We have introduced a method to find optimized structured media exhibiting large internal electric field amplitudes. The method is based on a genetic algorithm in which a spatial fitness function according to the computed field distribution in the interior of media is defined and maximized. The main feature of our method is that it enables localization of light at a desired layer (or more) within the structure.

Internal field distribution measurement in 1-D strongly anisotropic sub-wavelength periodic structures of finite length.

We report measurements of the internal field intensity distribution in finite length one dimensional strongly anisotropic sub-wavelength periodic structures in the vicinity of the photonic band gap (PBG) edge. The strong in-plane anisotropy of more than 10% index contrast is obtained via form birefringent sub-wavelength gratings. The structures have a period of less than half the wavelength.

Surface plasmon laser based on metal cavity array with two different modes.

The phenomenon of surface plasmon (SP) laser based on a square array of rectangular cavities cut into a metal substrate has been investigated. Both main resonant modes of the proposed structure can be used to realize SP laser while the working mechanism is different. We study the origin of these differences and propose an efficient design that exploits them.