Related papers: A negative permeability material at red light
We describe the use of a near-field scanning microwave microscope to image the permittivity and tunability of bulk and thin film dielectric samples on a length scale of about 1 micron. The microscope is sensitive to the linear permittivity,…
This paper presents modelled results for optical absorption in ultra-thin films of nickel, gold and silver across the solar spectrum. It is found in the case of nickel there is an optimum thickness for maximum solar absorption around…
We present an undergraduate lab that investigates weak localization in thin silver films. The films prepared in our lab have thickness, $a$, between 60-200 \AA, a mesoscopic length scale. At low temperatures, the inelastic dephasing length…
Silver nanoparticles embedded in a dielectric matrix are investigated for their potential as broadband-absorbing optical sensor materials. This contribution focuses on the electrical properties of silver nanoparticles at various…
We develop a quantitative description of giant asymmetry in reflectance, recently observed in semicontinuous metal films. The developed scaling-theory based technique reproduces the spectral properties of semicontinuous composites, as well…
We present total and specular reflectance measurements of various materials that are commonly (and uncommonly) used to provide baffling and/or to minimize the effect of stray light in optical systems. More specifically, we investigate the…
We investigate nonlinear transmission in a layered structure consisting of a slab of positive index material (PIM) with Kerr-type nonlinearity and a sub-wavelength layer of linear negative index material (NIM) sandwiched between…
We develop a theory of light transmission through an aperture-type near-field optical probe with a dissipative matter in its semiconducting core described by a complex frequency-dependent dielectric function. We evaluate the near-field…
We show that subwavelength imaging by negative index materials (NIM), related to their "soft" electromagnetic response, is very (and non trivially) sensitive to the surface properties. A minute deviation of dielectric permittivity epsilon…
Noble metals such as gold and silver are the primary metallic building blocks of metamaterial devices. Making subwavelength-sized structural elements from these metals seriously limits the optical performance of a device, however, and…
We present finite-differences time- domain calculations of the effective permitivity of a periodic array of Cu strip wires that are an ingredient needed in metamaterials for obtaining left-handed materials. We use the Cu frequency dependent…
An experimental investigation of sub-wavelength imaging by a wire medium slab is performed. A complex-shaped near field source is used in order to test imaging performance of the device. It is demonstrated that the ultimate bandwidth of…
Recently it has been shown that due to losses the claims on observation of negative refraction using metamaterials are questionable. In this paper we discus an interesting case that is based in almost zero permeability at a given frequency:…
We demonstrate propagation of plasmons in single crystalline silver nanostructures fabricated using a combination of a bottom-up and a top-down approach. Silver nanoplates of thickness around 65 nm and a surface area of about 100 \mu m^2…
Significant changes of the relative permittivity of a silver film have been detected using the surface plasmon resonance (SPR) method when a constant electric field is applied to a MDM (metal-dielectric-metal) nanostructure. The structure…
We show that narrow superconducting strips in superconducting (S) and normal (N) states are universally described by the model presenting them as lateral NSN proximity systems in which the superconducting central band is sandwiched between…
We demonstrate that arrays of split ring resonators (SRR) can have negative refractive index at optical frequencies (~1.4 eV). Our calculations reveal that the electric fields of radiation interact strongly with even symmetric SRR at…
We report the observation of imaging beyond the diffraction limit due to bound surface states in negative refraction photonic crystals. We achieve an effective negative index figure-of-merit [-Re(n)/Im(n)] of at least 380, ~125x improvement…
We analyze the reflection and transmission coefficients calculated from transfer matrix simulations on finite lenghts of electromagnetic metamaterials, to determine the effective permittivity and permeability. We perform this analysis on…
Low-energy reflectivity of electrons from single- and multi-layer graphene is examined both theoretically and experimentally. A series of minima in the reflectivity over the energy range of 0 - 8 eV are found, with the number of minima…