This PDF file contains the front matter associated with SPIE Proceedings Volume 7353, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

The homogeneous and transport properties of a set of metallic fibers was studied. The existence of a plasma frequency was shown and a precise formula was derived. A homogenized system for finite length ohmic wires was derived. Some numerical simulations were made to study the influence of disorder.

Man made artificial materials or metamaterials have attracted in the recent years a huge amount of interest owing to their potentials applications. Among these, we can cite perfect lens [1], hyper lens [2], electromagnetic cloak [3-7] and applications in non linear and/or guided optics [9-10]. In this paper we present and review some applications of infrared metallo- dielectric metamaterials developed in our group including the design of novel low loss negative index metamaterials, realistic cloaking in the infrared [7], sensing [8-9] and applications in non linear and/or guided optics [9-10] The basic physics of each presented application is reviewed and the use of these applications on functional photonic device is discussed.

Mechanisms of the negative and imaginary parts of the permittivity formation in 2D photonic macroporous silicon structures are investigated. Negative part of permittivity in 2D photonic macroporous silicon structures is determined by the polaritonic and surface electromagnetic mode formation. One of mechanisms of the imaginary permittivity formation is the electro-optical effect realized clearly in 2D photonic macroporous silicon structures in the near-IR area (impurity absorption). We investigated the "out-of-plane" optical absorption of 2D photonic macroporous silicon structures taking into account the optical mode formation and the electro-optical effect. The reflected electromagnetic waves at grazing angle of light incidence onto macropore surface change effectively the local surface electric field.

We present a thorough theoretical study of the optical properties of periodic structures built of silver and silica nanodisks in a sandwich-like configuration, by means of full electrodynamic calculations using the extended layer-multiple-scattering method. The strong coupling of the metallic nanoparticles and the resulting plasmon hybridization lead to collective electric and magnetic resonant modes, which can be tuned by changing the structural parameters, such as nanoparticle size and lattice constant. We analyze the response of single- and multi-layer architectures of ordered arrays of such nanosandwiches on a dielectric substrate to externally incident light and evaluate the corresponding effective permittivity and permeability functions. Our results reveal the existence of optical magnetism, with a strong negative effective permeability over a tunable spectral range at near-infrared and visible frequencies. We introduce the complex photonic band structure as a tool in the study of three-dimensional metamaterials and establish additional criteria for the validity of their effective-medium description. Our work demonstrates the efficiency of the recently developed extended layer-multiple-scattering method in the study of metamaterials of composite metal-dielectric particles of arbitrary shape.

The absorbers usually employed in everyday applications and the ultimate layouts recently proposed in the literature and based on unconventional material loading, are usually backed by a metallic plate. The metallic backing plays two main roles. On one hand, it is used to avoid power transmission on the other side of the absorber. On the other hand, it enables a boundary condition useful to create a reflected component that, combined with the impinging wave, cancels the reflection from the screen. In order to avoid a metallic backing, proper resonant structures may be employed. In this frame, it is possible to make use of metamaterials, that are artificial materials exhibiting properties not readily found in natural materials. The aim of the paper is to present a theoretical investigation relating to the design of compact microwave absorbers, made by a proper combination of two metamaterial slabs. The operation principle of that layout is based on the anomalous surface resonance, arising at the interface between two slabs, characterized by opposite signed values of the real parts of permittivities and/or permeabilities. We show that these bi-layers, when excited by an impinging electromagnetic wave, may support a localized interface resonance, whatever the total thickness of the entire setup is, for any angle of incidence, and no matter what the nature of the backing on the other side of the structure is. We also propose a new class of miniaturized inclusions, in order to be employed in practical layouts of innovative microwave absorbers.

Metamaterials in infrared and optical domain are mainly based on metal-dielectric composite. Collective excitations also called surface plasmons are thus the main mechanism in infrared metamaterials structures. Taking profit of the plasmonic interpretation instead of LC circuit approaches (better suited for microwave experiment) new approaches in understanding and engineering resonances is possible. In this paper we show numerically and experimentally how certain metamaterials can open opportunities in the engineering of plasmonic modes at the nanoscale for application including sensing and SERS (surface enhanced Raman Spectroscopy).

Boundary electrodynamic problem for a layer of effectively uniaxial absorbing metamaterial (MM) is solved. Proper inhomogeneous waves in the layer are neither TM (TE), when the optical axis is non-parallel to the incidence plane, nor purely evanescent. Features of excitation of particular waves with linear amplitude dependence on coordinates in MM are considered. Effect of small dielectric (magnetic) anisotropy and absorption of MM on imaging properties of the Veselago-Pendry lens is analyzed. It is shown that presence of a small anisotropy is a limiting factor much stronger than small losses, and careful account of effective permittivity (permeability) anisotropy for "superlens" devices is required.

A new kind of metamaterials based on hierarchically organized mirror channels with semitransparent walls, metamirror structures (MMS) is investigated theoretically and experimentally. Unusual optical properties of MMS like back reflection, negative refraction and some others are close to that exhibited by left-handed materials though the physical mechanisms are different. Being mechanically solid materials due to relatively small cell sizes (from one to tens microns), the MMS may have abnormal optical properties in wide wavelength range. The ray tracing is considered for different MMS geometries and types. It is shown that one reflection 2D MMS's based on rectangular elementary cells being properly curved possess lens properties and MMS lens generalized law is derived. Also, the MMS membranes may serve as filters of radiation both in reflection and transmission.

We apply the three-dimensional Discontinuous-Galerkin Time-Domain method to the investigation of the optical properties of V-shaped metallic nanostructures on dielectric substrates. In particular, we study in detail the possibility of controlling the spatiotemporal localization of radiation via chirped pulse excitations. Even for rather small structures, we find significant deviations from predictions based on quasi-static theory.

A simple analytical model has been developed within the scopes of the macroscopic Maxwell's equations. In the framework of this model the dispersion relation for plane waves has been calculated for the case of Cut-Wire (CW) and Split Ring Resonator (SRR) geometries. The dispersion relation has been compared with rigorous numerical calculations. A possible way to introduce the electric and magnetic material parameters has been suggested. Validity criteria and applicability limitations of the developed model are discussed. A new type of nonlinearity specific for the metamaterials - Multipole Nonlinearity - is identified based on the developed model, wheras the second harmonic generation (SHG) process is considered in detail

Khoo et al.¹ have introduced the concept of tuning of negative refractive index using nanosphere dispersed nematic liquid crystal (NDLC). Recently,^{2, 3} we have discussed anchoring forces as a new control parameter for negative-positive refraction index tuning in NDLC. In particular, we have calculated3 the phase diagrams in variables electric field - anchoring force for real and imaginary parts of permittivity and permeability for NDLC using averaged (global) value of refractive index for the inhhomogeneous system. In current paper we analyze an influence of anchoring forces and of spatial modulation of electric field on local distribution of negative refraction index in NDLC. The study constitutes a generalization of homogenous isotropic dielectric layer approximation used in papers.1 Inhomogeneous molecular order in planar NLC cells is modeled using Monte Carlo simulations with Lebwohl - Lasher effective hamiltonian and Rapini - Papoular term for anchoring forces.

The results of experimental observation of magneto-optical Kerr effect (MOKE) enhancement caused by surface plasmon-polaritons (SPP) excitation in 1D and 2D magnetoplasmonic crystals are presented. One-dimensional nickel magnetoplasmonic crystals have periodic structure formed by periodic nickel grooves made on nickel surface. The period of the structure is 320 nm and the depth of the grooves is 50 nm. The second group of the samples represents itself a 2D self-assembled hexagonally ordered monolayer of polystyrene (PS) microspheres with diameters from 500 to 760 nm and covered by 100- nm - thick nickel film. MOKE measurements performed in transversal configuration demonstrate that SPP excitation lead to transversal Kerr effect (TKE) enhancement resulting as a sharp peak in TKE spectrum.

We demonstrate the accuracy of the Finite Element Method (FEM) to characterize an arbitrarily shaped crossed-grating in a multilayered stack illuminated by an arbitrarily polarized plane wave under oblique incidence. To our knowledge, this is the first time that 3D diffraction efficiencies are calculated using the FEM. The method has been validated using classical cases found in the literature. Finally, to illustrate the independence of our method towards the shape of the diffractive object, we present the global energy balance resulting of the diffraction of a plane wave by a lossy thin torus crossed-grating.

In this contribution, we present the employment of a Genetic Algorithm (GA) based procedure to retrieve the effective permittivity and permeability of planar metamaterial samples. The approach used here is the same of standard Transmission/Reflection (TR) techniques, consisting in extrapolating the sample properties by inversion of its scattering coefficients. The proposed procedure makes use of parametric models for describing the inherently dispersive behavior of the involved materials. This approach eliminates the anomalous behavior of most of the commonly used inversion techniques, providing a consistent representation of the material in the working frequency range. The transition to bulk effective parameters is also investigated determining a proper sample thickness assuring the validation of the homogenization procedure.

Superfocusing of light, far better than the diffraction limit, is of crucial importance for scanning near-field optical microscopy (SNOM), optical chemical sensing, and nanolithography. For SNOM applications there are two typical geometries. The first are tapered-fiber metal-coated aperture probes, which are being constantly improved. The other are tapered metal or metal-coated apertureless tips, which are continuously brought to perfection. We propose a modification of a metal-coated fiber tip, which has an additional, thin, dielectric coating with refractive index greater than that of air, what leads to higher field enhancement at the tip. The excitation signal is an internal, radially polarized Laguerre-Gauss beam. There is no sound theoretical model to describe nanofocusing of plasmons and we limit the scope of investigations to body-of-revolution finite-difference time-domain (BOR FDTD) simulations using in-house code. We find that with an increase of the refractive index of nanocladdings the maximum enhancement occurs for increasingly longer wavelengths.

We analyze the scattering of the surface plasmon incident at a planar interface between two dielectrics. By using the scattering matrix technique, developed by Oulton et al. [Phys. Rev. B 76, 035408 (2007)], we calculate the transmission, reflection coefficients and radiative losses for oblique incident angles. We found that the transmission of a surface wave through a single interface between two dielectrics may be accompanied with radiation losses of 10-40 per cent of the plasmon energy.

The possibility to achieving the negative refraction by the system of the identical and homogenous spherical particles or porous implanted in the arbitrary ambient medium has been studied. The effective permeability and effective permittivity is investigated applying Mie scattering theory and Clausius-Mossotti expressions. It is shown that the magnetic and electric dipole resonance of the scattering field can not simultaneously occur in such system However, the simultaneous effective negative permittivity and effective negative permeability could be achieved in non resonance case. Possible range of the parameters of the particles, the porous and the media is established for the different frequencies of electromagnetic fields. The existence of the negative refraction for the system with noble metals (gold, silver) as a substance of the particles or of the surrounded medium is considered.

The study of the transmission properties of subwavelength apertures has become a very active area of research in electromagnetism. It is generally accepted that structuring the input surface of the metal film by periodic corrugations is very effective in the process of transmission enhancement through single apertures. Here instead of periodic corrugations, we propose to use periodic nano-strips placed before the input surface of the metal film to enhance the transmission of light through a nano-slit milled in the film. Influences of the structural parameters of periodic nano-strips on the transmission enhancement are investigated. The transmission efficiency through a 25nm-width silver nano-slit can be boosted to be η = 164 when six pairs of nano-strips are placed 50nm distant away from the incident surface of the silver film at λ0 = 1μm, which is originally η = 7.8 without any strips. This indicates that a large part of the incident light can be transformed into the localized guided wave with strong intensity, and then more light can flow through the nano-slit. We emphasize that periodic nano-strips can serve as an efficient receiving antenna to harvest light into the nano-slit.

Strong linear birefringence and dichroism is observed in optical metamaterial consisting of array of subwavelength elliptical holes in a silver film. Spectroscopic polarimetic measurements reveal structure's ability to convert linear polarized light by making it highly elliptical (ellipticity up to 1) and rotating the polarization plane by angles up to 90°. Refractive index difference for two eigenstates of the structure extracted from experimental data varies from 0.4 to 1.8 in the visible. Linear birefringence and dichroism effects together result in metamaterial's ability of separating frequency modes by putting them into different polarization modes.

We optimize the silver-dielectric layered flat lens in terms of three criteria:the variance of modulation transfer function (MTF) phase, the absolute values of the MTF phase, and the variance of this part of the phase spectrum which corresponds to the propagating waves only. All three characterise limited dependence of MTF on the range of spatial frequencies. The structure supports the resonant tunnelling of propagating and evanescent waves at distances of several wavelengths with a high transmission efficiency. Simulations are performed using the transfer matrix method and verified with the FDTD one. The resolution expressed with FWHM of the point spread function normalized with respect to wavelength reaches the value as small as 0.12, for the amplitude transmission of 40% and the thickness of the multilayer equals to 2.4 micrometers. For structures considered, we identify and explain a phenomenon that resembles focusing at a finite distance from the back plane.

In this paper we present technical details of a metal nanolens in the form of a free standing silver film with no hole on the optical axis and double-sided concentric corrugations. In a numerical experiment we analyze the nanolens performance, that is transmission and focusing of radially polarized beams of different full widths at half maximum and wavelengths from the visible range. Corrugations of the front surface couple incident light to surface plasmons and those on the back surface allow efficient reradiation. The silver lens of thickness 100 nm has five concentric corrugations of periodicity 500 nm with groove depth and width equal 40 nm and 100 nm, respectively. Focusing properties of such a structure are analyzed and optimized for wavelengths in the range from 400 to 600 nm. At intensity transmission of 10-25% of incident light achievable focal spot areas reach down to 0.15λ². For different illumination parameters the nanolens has focal lengths from 1 to 2 wavelengths. Without contribution of evanescent waves it focuses a far-field source into a farfield spot. The nanolens acts like a refractive optical system of high numerical aperture close to unity. Nanolenses of this kind can be used as light couplers in nanooptics.

In this work, I propose two methods for extending radiationless intereference to achieve an extreme subwavelength focus in the visible part of the optical spectrum. These methods are based on metal-insulator-metal (MIM) waveguide structures. The first uses the transverse evanescent field from a slit-coupled MIM waveguide. The second uses the highest order mode of a MIM waveguide array. Subwavelength focusing to a tenth of the optical wavelength is demonstrated numerically. Considering recent experiments, the proposed structures are practically viable. Methods to overcome other technical issues associated with this proposal are discussed.

Patterning of deeply subwavelength artificial nanomaterials (photonic crystals, plasmonic metamaterials) for the visible or near-infrared optical spectrum is a challenging task. Electron-beam lithography is often the method of choice thanks to its combination of flexibility, accuracy and availability in many research laboratories. We present an analytical model for large and dense arrays of photonic nanostructures which allows to predict the maximum fill ratio (radius divided by nearest neighbor distance) before the onset of resist shrinkage between the individual elements. The model includes geometrical parameters of the design (lattice constant, lattice symmetry), resist properties (resist contrast) and proximity parameters (beam broadening, backscatter range, backscatter efficiency). It is shown that the resist contrast has a significant impact on the achievable maximum fill ratio even for large nearest neighbor distances and that the beam broadening, i.e. the quality of the EBL equipment, is of paramount importance. The background energy level which is determined by the backscatter efficiency and the lattice symmetry is shown to have a weaker influence on the maximum fill ratio. The derived model can be used as a guideline in the project planning stage to predict achievable fill ratios at a planned lattice constant and consequently an assessment whether a desired functionality at a certain wavelength is possible.

Tb₃Sc₂Al₃O₁₂-TbScO₃ eutectic crystallizes in a rodlike microstructure, and its potential to exhibit photonic bandgap has been presented tentatively. In order to model its optical properties there is a need for precise determination of the optical properties of its component materials in a wide spectral range. Spectroscopic data in the range from 0.6 to 6.5 eV (190-2100 nm) were obtained using spectroscopic ellipsometer UVISEL, Horiba Jobin-Yvon. The measurement was completed with mid infrared reflection data using Bruker FTIR spectrometer in the spectral range from 7500 to 550 cm^-1. Optical functions were obtained using fitting of the data with model dielectric function fulfilling the Kramers-Kronig dispersion relations. Obtained optical functions enable to model the optical properties of self-organized eutectic micro- and nanostructures.

In this paper, the guidelines for the design of compact transmission-line (TL) metamaterial inspired monopole antennas are presented. The main difference between the proposed setup and the ones already present in the literature, based on phase-compensation phenomena enabled by TL-metamaterials, is that the present structure can be realized in fully planar technology. This peculiar feature allows minimizing the non-idealities introduced by vias and parallel plate capacitors used in conventional setups, which need to be soldered on the board. On the other hand, the proposed radiating devices are characterized by relatively low production costs, due to their planar configuration. The operation principles of the proposed radiators are detailed in the paper, giving the reader the necessary information to perform the design. Some examples are finally presented and tested through proper full-wave simulations performed with CST Studio Suite 2009.

We propose a multi-mode refractive index sensor based on split ring resonators (SRRs). By applying thin dielectric layer with varied refractive index on top of planar SRRs, we clarify the relationship among sensitivity, resonant modes and the size of SRRs based on standing-wave plasmonic resonances model. Significant peak shifts are observed in FTIR measurement spectrums, consisting with the simulation results which suggest impressive sensitivities closer to SPR or LSPR for different resonant modes. Next, the corresponding detection lengths of each mode were examined by varying the thickness of the overlaid dielectric layer. Lower modes include 1||, 2⊥ and 3|| show thickness saturation effect within 500 nm while higher modes such as 5||, 6⊥ and 7|| present longer detection length at micron scale, which namely, no saturation effect is observed when the thickness of dielectric layer increased to 2 um. This valuable merit enables the analysis of activation-dependent cellular interactions that other label-free techniques like surface plasmon resonance (SPR) are incapable of. In conclusion, the distinct sensing behavior including sensitivity and detection length of the multi resonant modes in SRRs was investigated, showing SRR-based sensors promise a real-time, operation frequency flexible and multi-mode solution for biological and chemical detection.

We investigate the tunneling of visible light through silver-dielectric superlenses working in the canalization regime. These structures feature high transmission and a sub-wavelength point spread function. They may serve as a novel element for mode coupling between ordinary waveguides, photonic crystal waveguides and plasmonic waveguides. We discuss the accuracy limits of homogenisation originally used in the definition of the canalisation regime. For this purpose we determine the actual anisotropic effective material parameters of the stack and compare them to those predicted by the effective medium theory. Further we optimise the structure with respect to the rigorously calculated transmission properties, rather than using the effective medium theory. Our analysis is based on the transfer matrix method formulated for multilayers with complex and uniaxially anisotropic permittivity and permeability tensors. The method does not assume the quasi-static approximation, retains validity for evanescent waves, and allows for including losses and dispersion into calculations.

We examine quasiperiodic multilayers arranged according to m-bonacci sequences that combine ordinary positive index materials and dispersive metamaterials with negative index in certain frequency ranges. When the averaged refractive index, in volume, of the multilayer equals zero, the structure does not propagate light waves and exhibits a forbidden band. In this contribution we recognize some approximated analytical expressions for the determination of the upper and lower limits of the above mentioned zero-average refractive index band gap.

The rigorous coupled wave theory dealing with optics of discontinuous two-dimensional (2D) periodic structures is reformulated by using the complex Fourier factorization method, which is a generalized implementation of the fast Fourier factorization rules. The modified approach yields considerably improved convergence properties, as shown on three samples of 2D gratingsmade as periodically arranged cylindrical holes on the top of quartz, silicon, and gold substrates. The method can also be applied to the calculation of 2D photonic band-gap structures or nonperiodic cylindrical devices, and can be generalized to elements with arbitrary cross-sections.