This PDF file contains the front matter associated with SPIE Proceedings Volume 7029, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

The characteristic near-field behavior of electromagnetic fields is open to a variety of interpretations. In a classical sense the term 'near-field' can be taken to signify a region, sufficiently close to some primary or secondary source, that the onset of retardation features is insignificant; a quantum theoretic explanation might focus more on the large momentum uncertainty that operates at small distances. Together, both near-field and wave-zone (radiative) features are fully accommodated in a retarded resonance propagation tensor, within which each component individually represents one asymptotic limit - alongside a third term that is distinctly operative at distances comparable to the optical wavelength. The propagation tensor takes different forms according to the level of multipole involved in the signal production and detection. In this presentation the nature and symmetry properties of the retarded propagation tensor are explored with reference to various forms of electric interaction, and it is shown how a suitable arrangement of optical beams can lead to the complete cancellation of near-fields. The conditions for such behavior are fully determined and some important optical trapping applications are discussed.

Transformation optics^1-5 uses the fact⁵ that optical media alter the geometry of space and time for light. A transformation medium performs an active coordinate transformation: electromagnetism in physical space, including the effect of the medium, is equivalent to electromagnetism in transformed coordinates where space appears to be empty. Some of the most striking applications of transformation optics include invisibility ^1,2,4 or perfect lensing based on negative refraction.⁵ Here we discuss an idea for a superantenna based on coordinate transformations. This device is invisible for most of the rays while it condenses others into a single point. Our device relies on a three-dimensional extension of optical conformal mapping ^2,3 as we describe below.

Up to date, electromagnetic metamaterials (EM₃) have been mostly fabricated by primary pattern generation via electron beam or laser writer. Such an approach is time-consuming and may have limitations of the area filled with structures. Especially, electron beam written structures are typically confined to areas of a few 100×100 μm². However, for meaningful technological applications, larger quantities of good quality materials are needed. Lithography, in particular X-ray deep lithography, is well suited to accomplish this task. Singapore Synchrotron Light Source (SSLS) has been applying its LIGA process that includes primary pattern generation via electron beam or laser writer, X-ray deep lithography and electroplating to the micro/nano-manufacturing of high-aspect ratio structures to produce a variety of EM³ structures. Starting with Pendry's split ring resonators, we have pursued structure designs suitable for planar lithography since 2002 covering a range of resonance frequencies from 1 to 216 THz. More recently, string-like structures have also been included. Latest progress made in the manufacturing and characterization of quasi 3D metamaterials having either split ring or string structures over areas of about ≈1 cm² extension will be described.

We have measured the microwave transmission between 12 and 18 GHz through wire arrays formed into two dimensional square lattices. One array made of copper wire 0.14 mm in radius consisted of five rows by 21 columns having a lattice constant of 5.2 mm. This array exhibited a pass band above 15 GHz, in good agreement with the calculated plasma frequency found from an expression for the permittivity derived in the long wavelength limit. A second array was made with Nichrome wire of radius 18 μm and lattice constant 1.1 mm. This array was filled with dielectric loaded with powdered magnetite. A sample of this metamaterial 5.8 mm thick and with no externally applied magnetic field exhibited a pass band above 17 GHz. Implications for creating metamaterials with a negative index of refraction from wire arrays embedded in a magnetic host are discussed.

A metamaterial designed to have simultaneous negative permittivity and permeability may be built from a cubic lattice of spheres and a three dimensional wire grid embedded in a host medium. Based on reported theory, the spheres must have higher permittivity than the surrounding medium and be smaller than the wavelength of the electromagnetic radiation in the host medium. Metamaterials based on embedded spheres are expected to be isotropic. This paper presents simulated and effective medium theory reflection and transmission parameters of a plane parallel structure of this new metamaterial. The predicted behavior exhibits a pass band structure where the permittivity and permeability are simultaneously negative.

Optical localization in one-dimensional very long disordered photonic bandgap structures is characterized by the upper Lyapunov exponent of the infinite random matrix product model. This upper (and positive) Lyapunov exponent, or localization factor (inverse localization length), is, at least theoretically, calculable from Furstenberg's formula. This formula not only requires the probability density function for the random variables of the random transfer matrix, but also requires the invariant probability measure of the direction of the vector propagated by the long chain of random matrices. This invariant measure is generally only calculable numerically, and when the transfer matrices are in the usual real basis, or even a plane wave basis, the invariant measure takes no consistent form. However, by using a similarity transformation which moves the fixed points of the bilinear transformation corresponding to the long random matrix product, we can put the random matrix product in the so-called real hyperbolic-canonical basis. The aim of this change of basis is to place the attracting fixed point at the origin and the repelling fixed point at infinity. The invariant measure, as a result, is dramatically simplified, approaching a probability mass function with mass concentrated around the angle zero.

The study of the interaction of polarized light with biological materials such as human tissue has applications in medical diagnosis and medicine. Polarized light that is reflected or transmitted through biological specimens can also be used to detect and identify biological and chemical threat agents. The determination of the silent foot prints of the chiral properties of the biological materials on scattered polarized light, is the basis for these investigations. The polarization states of electromagnetic waves which in general are elliptical, are represented by its Stokes vector. Scattered light is completely characterized by the 4 x 4 Mueller matrix that relates the scattered Stokes vector to the incident Stokes vector. It is of primary importance to identify which of the sixteen elements of the Mueller matrix for reflected and for transmitted light are most sensitive to the chiral properties of the biological materials. The explicit analytical dependence of these specific elements of the Mueller matrix, upon the angles of incidence and scatter, upon the wavelength and upon the type of chirality has the potential to provide experimentalists with guidance in determining the optimum use of optical polarimetric scatterometers to detect and identify biological materials through their chiral properties.

A two dimensional design of an ultra-thin, wide-angle perfect absorber for infrared light is proposed. The geometry of the structure is simple enough to be realized with present fabrication techniques, yet it is shown numerically to exhibit nearly 100% absorption at the resonant wavelength that is tunable by adjusting its geometric parameters. The angular dependence of the absorption for different polarizations of the incident radiation is presented, remaining above 95% in P-polarization and 90% in S-polarization (in the orthogonal incidence plane) for the incidence angles up to 45°. The robustness and tunability of the structure with respect to the variations of its geometric parameters is quantified.

By way of examples in vacuum and media, we show that the criterion used widely to determine the occurrence of negative phase velocity propagation is not covariant. A new covariant criterion is presented that reduces to the previous criterion in the rest frame of a medium. The new criterion requires calculation of the plane wave electromagnetic modes of a generalized medium in terms of the four-potential, A_ν. Some of the subtleties of removing the gauge freedom inherent in A_ν are highlighted.

Although a lot of progress has been made in the field of integrated photonics, the integration density of photonic integrated circuits remains much lower than their electronic counterparts, mainly limited by an inherent wavelength condition on the size of their constituents. Only recently, researchers have tried to overcome this wavelength condition, e.g., by the use of plasmonics and left-handed materials. In this contribution, we want to present a waveguide - an essential component in photonic circuits - that has the possibility of confining light in a waveguide with sub-wavelength diameter [Appl. Phys. Lett. 92, 203111, 2008]. This waveguide uses a left-handed material in order to control the phase evolution of an optical mode during propagation through the waveguide. We calculate the contributions to this phase shift from the optical path length and from the reflections at the cladding interface and we show that the control of this phase shift by a left-handed material allows for tailoring the properties of the optical modes. From the calculated mode profile and dispersion relation, we show that the proposed geometry allows for waveguides with a thickness that is at least one order of magnitude smaller than the optical wavelength. This miniaturization does not inversely affect the confinement properties of the propagating modes, i.e., the optical mode diameter remains comparable to the waveguide thickness and the light does not extend far into the cladding.

A new homogenization theory has been proposed by Bouchitte and Felbacq¹ for a bounded obstacle made of periodically disposed parallel high conducting metallic fibers of finite length and very thin section. Although the resulting constitutive law is non local, a cut-off frequency effect can be evidenced when fibers become infinitely long. In this paper we present a very surprising byproduct of this model: by reproducing periodically the same kind of obstacle at small scale and after undergoing a reiterated homogenization procedure, we obtain a local effective law described by a permittivity tensor that we explicit as a function of the frequency. An important issue is that the eigenvalues of this tensor have real part changing of sign and possibly very large within some range of frequencies.

Metamaterials, which maybe the answer to "perfect lensing", are often fabricated as a periodic array of elements which exhibit negative refractive index or negative permeability/permittivity. In this work, we outline and illustrate a framework that can model propagation through a homogeneous and random mixture of positive and negative index materials. We achieve this by using a matrix-based multilayered approach, and a random sequence of positive and negative index materials, and by incorporating all possible combinations of such layers. Plane wave propagation is investigated, and aggregated transmittivity is calculated. We show that near-zero net refractive index maybe achieved through a random homogeneous mixture of positive and negative index materials.

We consider the propagation of surface plasmon polaritons in anisotropic metamaterial systems. It is shown that material anisotropy can be used as an efficient tool to independently control effective modal index and spatial profile of the surface mode. In particular, it is possible to utilize anisotropic media to completely eliminate the out-of-plane scattering of surface plasmons, realizing the paradigm of truly two-dimensional optics where surface modes are completely uncoupled from their volume counterparts. The developed formalism yields a mapping between the familiar laws of 3D optics and the behavior of two-dimensional surface optics. The mapping is illustrated on examples of plasmonic refractor and plasmonic Bragg reflector. The tolerance of the surface optics paradigm with respect to material imperfections is assessed with perturbation theory and with numerical solutions of Maxwell's equations. Practical realizations of dynamical plasmonic circuits and extensions of the developed framework to volume-guiding structures are discussed.

Chemical engineering of metamaterials to reduce optical losses is studied by first principle density functional theory. Contribution of the surface states to optical losses is studied by calculations of the imaginary part of the dielectric function for several organic molecules (water, methanol, and ethanol) adsorbed on the (111) surface of Ag nano-slabs. Substantial modifications of optical functions of metallic nano-slabs in near infrared and visible spectral regions, caused by surface states and molecular adsorption, are predicted, discussed, and compared to experimental data.

A fundamental approach to a slowly varying amplitude formulation for nonlinear waves in metamaterials will be established. The weakly nonlinear slowly varying amplitude approach will be critically examined and some misunderstandings in the literature will be fully addressed. The extent to which negative phase behaviour has a fundamental influence upon soliton behaviour will be exposed. The method will deploy nonlinear diffraction and a special kind of diffraction-management. This is additional to a detailed modulation instability analysis. The examples given involve waveguide coupling and a nonlinear interferometer. In addition, a strongly nonlinear approach will be taken that seeks exact solutions to the nonlinear equations for a metamaterial. A boundary field amplitude approach will be developed that leads to useful eigenvalue equations that expose, in a very clear manner, the possibility that new kinds of waves can be generated.

For inhomogeneous mediums the optical Magnus effect has been derived. The metamaterials fabricated from amorphous ferromagnet Co-Fe-Cr-B-Si microwires are shown to exhibit a negative refractive index for electromagnetic waves over wide scale of GHz frequencies. Optical properties and optical Magnus effect of such metamaterials are tunable by an external magnetic field. Microwave permeability of glass-coated ferromagnetic amorphous microwire exhibiting a weak negative magnetostriction has been studied. The diameter of the microwire was about 20 μm and the diameter of the metal core was about 12 μm. The microwire was wound to comprise a 7/3 washer-shaped composite sample with the volume fraction of magnetic constituent of about 10%. The permeability of the composite sample was measured in a coaxial line in the frequency range from 0.1 to 10 GHz. The composite was found to exhibit a negative permeability within the frequency range from approximately 0.7 to 1.5 GHz, with the permeability being as low as -0.4. Therefore, microwire-based composites, particularly, crossed arrays of microwires may be employed to develop metamaterials for microwave applications. In the composite, the negative microwave permeability is due to the natural ferromagnetic resonance and the negative microwave permittivity is due to the inherent inductance of the wire. Such metamaterials are advantageous in simple design, isotropic in-plane performance, and possible tunability of performance by external magnetic bias. However, for a feasible metamaterial fabricated from microwire arrays, the wires have to exhibit higher magnitude of the ferromagnetic resonance, higher quality factor, and higher resonance frequency.

In this work, we describe the behavior of the electromagnetic field on a Nanostructured interface using the coupled mode theory. The study is performed by associating time-dependent parameters to a set of polarized particles randomly distributed on an dielectric substrate. As a result, we obtain the conditions to generate a negative refractive index as a function of the distance between two particles in harmonic oscillation, in this way we show the possibility to synthetize Metamaterials from the nanoparticles arrays.

In this research an intelligent emotional learning controller, Takagi- Sugeno- Kang (TSK) is applied to govern the dynamics of a novel Ionic-Polymer Metal Composite (IPMC) actuated manipulator. Ionic-Polymer Metal Composites are active actuators that show very large deformation in existence of low applied voltage. In this research, a new IPMC actuator is considered and applied to a 2-dof miniature manipulator. This manipulator is designed for miniature tasks. The control system consists of a set of neurofuzzy controller whose parameters are adapted according to the emotional learning rules, and a critic with task to assess the present situation resulted from the applied control action in terms of satisfactory achievement of the control goals and provides the emotional signal (the stress). The controller modifies its characteristics so that the critic's stress decreased.

We explore the electromagnetic response of one-dimensional photonic crystals containing slabs of uniaxial anisotropic indefinite metamaterials (IMMs) with hyperbolic spatial dispersion characteristics. A band structure classification has been previously made according to the sign of the permittivity and permeability parameters for the particular case of optical axis perpendicular to the slab interfaces. To extend this study, here we analyze how the dispersive behavior of each constitutive parameter affects the multilayer band structure. We consider two orientations of the optical axis, perpendicular and parallel to the slab interfaces, and TE and TM modes. Particular attention is paid to the effects of material dispersion on the existence of non-Bragg band gaps.