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Engineering of a refractive index profile is a powerful method for controlling electromagnetic fields. In this paper, we investigate possible realization of isotropic gradient refractive index media at optical frequencies using two-dimensional graded photonic crystals. They consist of dielectric rods with spatially varying radii and can be homogenized in(More)
This paper discusses the fundamentals, applications, potential, limitations, and future perspectives of polarized light reflection techniques for the characterization of materials and related systems and devices at the nanoscale. These techniques include spectroscopic ellipsometry, polarimetry, and reflectance anisotropy. We give an overview of the various(More)
We demonstrate for the first time a fast and easy nanoimprint lithography (NIL) based stacking process of negative index structures like fishnet and Swiss-cross metamaterials. The process takes a few seconds, is cheap and produces three-dimensional (3D) negative index materials (NIMs) on a large area which is suitable for mass production. It can be(More)
Graphene is emerging as a promising material for plasmonics applications due to its strong light-matter interactions, most of which are theoretically predicted but not yet experimentally realized. Therefore, the integration of plasmonic nanoparticles to create metal nanoparticle/graphene composites enables numerous phenomena important for a range of(More)
The design of electromagnetic invisibility cloaks is based on singular mappings prescribing zero or infinite values for material parameters on the inner surface of the cloak. Since this is only approximately feasible, an asymptotic analysis is necessary for a sound description of cloaks. We adopt a simple and effective approach for analyzing electromagnetic(More)
We present a study on relation between the refraction and rightness effects in photonic crystals applied on a 2D square lattice photonic crystal. The plane wave (the band and equifrequency contour analyses) and FDTD calculations for both TM and TE modes revealed all possible refraction and rightness cases in photonic crystal structures in the first three(More)
We report on the fabrication and characterization of silicon-on-insulator (SOI) photonic crystal slabs (PCS) with commensurately embedded germanium quantum dot (QD) emitters for near-infrared light emission. Substrate pre-patterning defines preferential nucleation sites for the self-assembly of Ge QDs during epitaxial growth. Aligned two-dimensional(More)
Gallium (Ga), a group III metal, is of fundamental interest due to its polymorphism and unusual phase transition behaviours. New solid phases have been observed when Ga is confined at the nanoscale. Herein, we demonstrate the stable coexistence, from 180 K to 800 K, of the unexpected solid γ-phase core and a liquid shell in substrate-supported Ga(More)
Lead sulfide quantum dots represent an emerging photovoltaic absorber material. While their associated optical qualities are true for the colloidal solution phase, they change upon processing into thin-films. A detailed view to the optical key-parameters during solid-film development is presented and the limits and outlooks for this versatile and promising(More)