This PDF file contains the front matter associated with SPIE Proceedings Volume 9160, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

We present the exciting functionalities of gap surface plasmon-based metasurfaces for light manipulation in reflection due to the excitation of gap surface plasmon resonances allowing for efficient control of phase and amplitude of reflected light. We specifically demonstrate that such plasmonic metasurfaces can be utilized for efficient unidirectional polarization-controlled coupling of incident light to propagating surface plasmon polariton modes. Fabricated metasurfaces that operate at telecommunication wavelengths 1500-1600nm feature a maximum coupling efficiency of ~25% for either of two linear polarizations of incident light and surface plasmon directivity exceeding 100.

We demonstrate a metamaterial Huygens’ surfaces for near-infrared frequencies using high-permittivity all-dielectric nanoparticles with tailored Mie-type resonances as meta-atoms. We experimentally measure 360 degrees phase variation of the transmitted light in combination with high transmittance values for light passing through a fabricated metasurface exhibiting spectrally overlapping electric and magnetic dipole-type modes in the near-infrared spectral range. Our experimental measurements are in excellent agreement with numerical simulations and analytical calculations. High transmittance in combination with the simultaneously observed complete phase coverage is key for the realization of a wide range of applications including efficient wavefront shaping, dispersion control devices, and holograms.

We systematically study both experimentally and theoretically the links between the lattice symmetries of metasurfaces and their optical properties at both normal and oblique illumination. We attribute different symmetry elements to number of polarization phenomena. In particular, we predict analytically and verify experimentally the influence of rotational axes, mirror planes and inversion centres on optical activity, circular dichroism and asymmetric transmission. We fabricate and test nanostructured optical metasurfaces with four different inner structures: square and hexagonal lattices, quasicrystalline layout, and amorphous arrangement. We demonstrate the ability to enhance/suppress particular optical response by appropriate choice of the metasurface’s symmetry.

We demonstrate a novel artificial optical material, the “photonic hyper-crystal”, which combines the most interesting features of hyperbolic metamaterials and photonic crystals. Similar to hyperbolic metamaterials, photonic hyper-crystals exhibit broadband divergence in their photonic density of states due to the lack of usual diffraction limit on the photon wave vector. On the other hand, similar to photonic crystals, hyperbolic dispersion law of extraordinary photons is modulated by forbidden gaps near the boundaries of photonic Brillouin zones. Three dimensional self-assembly of photonic hyper-crystals has been achieved by application of external magnetic field to a cobalt nanoparticle-based ferrofluid. Unique spectral properties of photonic hyper-crystals lead to extreme sensitivity of the material to monolayer coatings of cobalt nanoparticles, which should find numerous applications in biological and chemical sensing.

Hyperbolic optical metamaterials is an interesting class of extremely artificial materials that exhibit metallic or dielectric properties depending on the polarization. Effective medium approach predicts that the wavevectors can be infinitely high, although in practicability they are limited by the periodicity of the metamaterials (often referred to as “nonlocality”). In this talk we examine a different approach, based on Kronig Penney modal and show how one can obtain dispersion, group velocity, density of states, and the loss of hyperbolic metamaterial without reverting to extensive numerical calculations. Our approach shows that hyperbolic materials can be interpreted as coupled arrays of gap plasmons, and also reveals an interesting fact, missing form effective medium model) that elliptical and hyperbolic dispersions can coexist in the material at certain frequencies.

We study the spontaneous emission enhancement inside a hyperbolic metamaterial, composed of a periodic stack of silver and silicon layers. After showing that the decay rate outside the multilayer can be spectrally altered via the metallic filling ratio, we embed the source within the individual silicon layers, and predict a 3-fold increase of the Purcell factor with respect to its outer value. Then we include the emitter in a polymethyl-methacrylate (PMMA) layer, and extract the plasmonic modes by means of a triangular and a rectangular grating, obtaining respectively a 10-fold and 6-fold enhancement in the power emitted into the far-field.

We explain the design of one dimensional Hyperbolic Metamaterials (HMM) using a genetic algorithm (GA) and provide sample applications including the realization of negative refraction. The design method is a powerful optimization approach to find the optimal performance of such structures, which “naturally” finds HMM structures that are globally optimized for specific applications. We explain how a fitness function can be incorporated into the GA for different metamaterial properties.

Dense photonic integration requires miniaturization of materials, devices and subsystems, including passive components (e.g., engineered composite metamaterials, filters, etc.) and active components (e.g., lasers, modulators, detectors). This paper discusses passive and active devices that recently have been demonstrated in our laboratory, including monolithically integrated short pulse compressor utilized with silicon on insulator material platform and design, fabrication and testing of nanolasers constructed using metal-dielectric-semiconductor resonators confined in all three dimensions.

Functional optical metamaterials usually consist of absorbing, anisotropic and often non-centrosymmetric structures of a size that is only a few times smaller than the wavelength of visible light. If the structures would be substantially smaller, excitation of higher-order electromagnetic multipoles in them, including magnetic dipoles, would be inefficient. As a result, the material would act as an ordinary electric-dipole material. The required non-negligible size of metamolecules, however, makes the material spatially dispersive, so that its optical characteristics depend on light propagation direction. This phenomenon significantly complicates the description of metamaterials in terms of conventional electric permittivity and magnetic permeability tensors. In this work, we present a simple semianalytical method to describe such spatially dispersive metamaterials, which are also allowed to be optically anisotropic and non-centrosymmetric. Applying the method, we show that a strong spatial dispersion, combined with absorption and optical anisotropy, can be used to efficiently control propagational characteristics of optical beams.

We study the strong coupling of dye molecules to surface plasmons polaritons of thin silver films. The dispersion splits into three branches and demonstrates avoided crossing, characteristic of strong coupling. The dispersion is further modified, when gain is introduced, by strongly pumping the dye molecules. In a series of complementary experiments, we also show that dye molecules can be strongly coupled to localized plasmons modes of rough silver films and also multilayered hyperbolic metamaterials. Our preliminary results could pave the way for a new class of hybrid plasmonic materials and metamaterials.

The classical theory of electrodynamics is built upon Maxwell’s equations and the concepts of electromagnetic field, force, energy and momentum, which are intimately tied together by Poynting’s theorem and the Lorentz force law. Whereas Maxwell’s macroscopic equations relate the electric and magnetic fields to their material sources (i.e., charge, current, polarization and magnetization), Poynting’s theorem governs the flow of electromagnetic energy and its exchange between fields and material media, while the Lorentz law regulates the back-and-forth transfer of momentum between the media and the fields. The close association of momentum with energy thus demands that the Poynting theorem and the Lorentz law remain consistent with each other, while, at the same time, ensuring compliance with the conservation laws of energy, linear momentum, and angular momentum. This paper shows how a consistent application of the aforementioned laws of electrodynamics to moving permanent dipoles (both electric and magnetic) brings into play the rest-mass of the dipoles. The rest mass must vary in response to external electromagnetic fields if the overall energy of the system is to be conserved. The physical basis for the inferred variations of the rest-mass appears to be an interference between the internal fields of the dipoles and the externally applied fields. We use two different formulations of the classical theory in which energy and momentum relate differently to the fields, yet we find identical behavior for the restmass in both formulations.

We consider polarization and off-axis incidence effects for one-dimensional random stacks consisting of alternating and non-alternating layers of positive and negative index materials, with index of refraction and thickness discretely disordered. Such long randomly disordered systems exhibit Anderson localization, whose effects can be studied via the Lyapunov exponent of the product of independent identically distributed random transfer matrices modeling the stack. We use Furstenberg’s integral formula to calculate Lyapunov exponents for s and p polarizations, and for a range of angles of incidence for these random matrix models. Furstenberg’s integral formula requires integration with respect to the probability distribution of the randomized layer parameters, and integration with respect to the so-called invariant probability measure of the direction of the vector propagated by the long chain of random matrices. This invariant measure can rarely be calculated analytically, so some numerical technique must be used to produce the invariant measure for a given random matrix product model. Here we use the algorithm of Froyland-Aihara, especially suited for discretely disordered parameters, to calculate the invariant measure. This algorithm produces the invariant measure from the left eigenvector of a certain sparse row-stochastic matrix. This sparse matrix represents the probabilities that a vector in one of a number of discrete directions will be transferred to another discrete direction via the random transfer matrix. The Froyland-Aihara algorithm thus provides a non-Monte Carlo method to calculate localization effects, with potential reduction in computation time compared to traditional layer or vector iteration methods.

We demonstrate heat flux bending in a multilayered composite considering an effective thermal medium approximation. We show that when the orientation of the composite is physically rotated with respect to the applied temperature gradient , that the resultant thermal conductivity tensor can be modified to be anisotropic, with non-zero off- diagonal elements. The resultant anisotropy was found to be dependent on the angle of rotation as well as the ratio of the thermal conductivities of the constituent materials. We experimentally demonstrate the bending of the heat flux in three such multilayered composites made by alternately stacking 2mm layers of copper ~ 391 W/mK and alloy steel ~ 42 W/mK respectively with three different rotation angles. We show that the resultant heat flux vectors in the composites are oriented at an angle with the applied temperature gradient , due to anisotropy in the thermal conductivity. Our experiments and analysis indicate that heat flux does not have to be collinear with the applied temperature gradient, e.g. the temperature gradient in a particular direction can drive heat flux in an orthogonal direction. Our studies have implications in thermal energy management with possible utility in portable electronics, nano-combustible systems, solar energy utilization etc.

We report angle-resolved infrared reflectivity measurements from a substantially sub-wavelength thickness, textured, metal-dielectric-metal microcavity. The two-dimensional surface texturing causes the structure to support flat-band, surface plasmon modes exhibiting efficient diffractive coupling to free radiation. Additionally, we observe a transverse magnetic mode that is due to phonon absorption within the dielectric spacer layer of the structure. The nature of these electromagnetic modes, their mutual interactions and the device band structure has been characterized by numerical modelling of the experimental data. With the exception of the phonon mode, the analyzed modes show that absorption of incident radiation predominantly occurs in the metal layers of the structure and at frequencies dictated by the geometry of the patterned top surface.

Controlling photonic processes on length scales below the diffraction limit requires structural elements with dimensions much smaller than the wavelength. Recently, novel plasmonic metamaterial has been developed based on arrays of aligned plasmonic nanorods which can be designed to exhibit hyperbolic dispersion or epsilon-near-zero behaviour. This metamaterial provides a flexible platform with tuneable optical properties across the visible and telecom spectral range. Such metamaterials can be used instead of conventional plasmonic metals for designing plasmonic waveguides, plasmonic crystals, label-free bio- and chemo-sensors, for development nonlinear plasmonic structures with the enhanced nonlinearities, and controlling emitters. In this talk, we will overview fundamentals and applications of plasmonic nanorod metamaterial for designing new types of nanostructured plasmonic platforms, bio- and chemical sensing components, and nonlinear optical devices.

Purely organic materials with near-zero dielectric permittivity can be easily fabricated. Here we develop a theory of non-steady-state organic plasmonics with strong short laser pulses that enable us to obtain near-zero dielectric permittivity during a short time. We have proposed to use non-steady-state organic plasmonics for the enhancement of intersite dipolar energy-transfer interaction in the quantum dot wire that in°uences on electron transport through nanojunctions. Such interactions can compensate Coulomb repulsions for particular conditions. We propose the exciton control of Coulomb blocking in the quantum dot wire based on the non- steady-state near-zero dielectric permittivity of the organic host medium.

In this paper, we design layered composite meta-structures to investigate its’ effect on the optical activity and circular dichroism (CD). The layered composite meta-structures consist of thin gammadion nanostructure with thickness λ/10, where λ is the incident wavelength. The layered meta-structures are alternate between a dielectric and gold (AU) material. Each layered composite meta-gammadion is arranged together in an array of pitch 700 nm. In the first case, 3 layers of meta-gammadion, with metal-insulator-metal (MIM) and insulator-metal-insulator (IMI) configuration are simulated with material properties from optical hand book. There are 3 modes in the CD spectrum, which can be characterized into Bloch CD mode and hybrid CD modes. Compared with the CD spectrum of whole structure of gammadion in gold with same total height, the CD of the MIM layered composite are larger. When the number layer increase to 5, it is observed that the CD is reduced by 30% and there is a red shift in the Bloch CD mode and a slight blue shift in the hybrid CD modes. By further increasing the number of layers to 7, we observed further CD increment and larger wavelength shift in the CD modes. The layered composite meta-gammadion is fabricated using template stripping method. Experimental results also show excellent agreement with the simulation results for CD and wavelength shift. We submerge the layered meta-gammadion into a solution of chiral molecules. The CD spectrum of the meta-gammadion shows a larger wavelength shift compared to pure metal structures. This indicate a more sensitive and robust detection of chiral molecules.

Light beams with unusual forms of wavefront offer a host of useful features to extend the repertoire of those developing new optical techniques. Complex, non-uniform wavefront structures offer a wide range of optomechanical applications, from microparticle rotation, traction and sorting, through to contactless microfluidic motors. Beams combining transverse nodal structures with orbital angular momentum, or vector beams with novel polarization profiles, also present new opportunities for imaging and the optical transmission of information, including quantum entanglement effects. Whilst there are numerous well-proven methods for generating light with complex wave-forms, most current methods work on the basis of modifying a conventional Hermite-Gaussian beam, by passage through suitably tailored optical elements. It has generally been considered impossible to directly generate wave-front structured beams either by spontaneous or stimulated emission from individual atoms, ions or molecules. However, newly emerged principles have shown that emitter arrays, cast in an appropriately specified geometry, can overcome the obstacles: one possibility is a construct based on the electronic excitation of nanofabricated circular arrays. Recent experimental work has extended this concept to a phase-imprinted ring of apertures holographically encoded in a diffractive mask, generated by a programmed spatial light modulator. These latest advances are potentially paving the way for creating new sources of structured light.

Homogeneous negative refractive index materials are introduced as an alternative to normally utilized inhomogeneous metamaterials. The theory of such materials was developed several years ago (A. Kussow and A. Akyurtlu, PRB 78, 205202 (2008)), and the effect is due to the coexistence of the spin-wave mode with the plasmonic mode, and both modes are activated by the electromagnetic field with simultaneous negative permittivity and permeability responses within the narrow frequency band close to the ferromagnetic resonance. To justify this theory, the thin films of ferromagnetic semiconductor, Cr-doped indium oxide, were fabricated, with clearly measured ferromagnetism at high saturation magnetization and a Curie temperature which is much higher than room temperature. The refractive index, within mid-IR, was extracted from combined transmittance and reflectance data and was compared with theoretical prediction. Also, a direct standard beam displacement method validates the effect of negative refraction in this material.

Chirality effect has been reported from the interaction of light with chiral plasmonic nanostructures. Such nanostructure enhances the chirality response of the chiral molecules and provides a good platform for biochemical sensing. The ability to detect chiral molecules has been a long term goal of biologists and chemist because chirality is inherent in macromolecules such as proteins and DNA in human body. One of the challenging problems is manipulation of the CD spectrum. Here, we investigate the switchable chiral effects of subwavelength nanostructures array with the unit cell makes up of double-layered nanostrips in four-fold rotationally symmetric arrangement. The switchable chirality effect has observed in both plasmonic and Bloch modes when the mutual angle between the first layer and second layer rotates with respect to each other. The magnitude of chirality changes from positive to negative when the mutual angle rotates from 0^o to 90^o. In the order hand, the nanostructures change from right-handed to left-handed structures without altering the polarization of incident light, or vice versa, upon the mutual rotation angles. Thus, by manipulating the mutual rotation angle, the handedness of the nanostructure will switch and cause the reversal of the outgoing light.

Surface modification of silica spheres with 3-(Trimethoxysilyl)propylmethacrylate (TMSPM) has been performed at ambient condition. However, the FTIR spectra and field emission scanning electron microscope (FESEM) images show no evidence of the surface modification. The reaction temperatures were varied from 60 to 80 °C with various reaction periods. Small absorption shoulder of the C=O stretching vibration was at 1700 cm^-1, and slightly increased with the increase of the reaction time at 60 °C. The clear absorption peak appeared at 1698 cm^-1 for the spheres reacted for 80 min at 70 °C and shifted toward 1720 cm^-1 with the increase the reaction time. Strong absorption peak showed at 1698 cm^-1 and shifted toward 1725 cm^-1 with the increase of the reaction time at 80 °C. The spheres were dispersed to methanol and added photoinitiator (Irgacure-184). The solution was poured to a patterned glass substrate and exposed to the 254 nm UV-light during a self-assembly process. A large area and crack-free silica sphere film was formed. To increase the mechanical stability, a cellulose acetate solution was spin-coated to the film. The film was lift-off from the glass substrate to analyze the surface nanostructures. The surface nanostructures were maintained, and the film is stable enough to use as a mold to duplicate the nanopattern and flexible.

We propose and discuss a novel micro-machined reconfigurable terahertz (THz) filter based on graphene. The key components are the periodic metal ring with several gaps where active graphene strips are placed. We can easily adjust the resonance frequency of the terahertz filter by varying a couple of parameters such as the inner and outer radius of the metal ring, the gap, the number of graphene layers, and by dynamically varying the conductivity of each graphene layer. This work explains the principle of operation of the device, its design based on numerical simulations, its fabrication process, and also presents experimental results.

The analytically realization of electromagnetic wave frequency conversion in a time-varying medium was shown by the two methods. The first method considers the optical analog of the electromagnetic wave redshift in the expanding universe using the transformation optics mathematical approach. The second one describes the transient process of pulse electromagnetic wave interaction with the time-varying medium using method of the second order Volterra integral equation. The frequency conversion was shown for several types of commercial laser wavelengths.

Holograms, the optical devices to reconstruct pre-designed images, have been evolved dramatically since the advances in today’s nanotechnology [1-4]. Metamaterials, the sub-wavelength artificial structures with tailored refraction index, enable us to design the meta-hologram working in arbitrary frequency region. Here we demonstrated the first reflective type, dual image and high efficient meta-hologram with the incident angle as well as the coherence of incident wave insensitivity in visible region at least from λ = 632.8 nm to λ = 850 nm. The meta-hologram is composed of 50-nm-thick gold cross nano-antenna coupled with 130-nm-thick gold mirror with a 50-nm-thick MgF₂ as spacer. It shows different images “RCAS” and “NTU” with high image contract under x- and y-polarized illumination, respectively. Making use of the characteristic of meta-materials, these optical properties of proposed meta-hologram can be transferred to arbitrary electromagnetic region by scale-up the size of the unit cell of meta-hologram, leading to more compact, efficient and promising electromagnetic components.

Albert Einstein’s theory of relativity imposes stringent limitations to making macroscopic objects invisible with respect to electromagnetic light waves propagating in vacuum. These limitations are not relevant though for propagation of light in diffusive media like fog or milk because the effective energy speed is significantly lower than in vacuum due to multiple scattering events. Here, by exploiting the close mathematical analogy between the electrostatic or near-field limit of optics on the one hand and light diffusion on the other hand, we design, fabricate, and characterize simple core-shell cloaking structures for diffusive light propagation in cylindrical and spherical geometry.

In recent work, electromagnetic propagation velocities for plane waves in dispersive metamaterials were calculated assuming frequency dispersion up to the second order. The three velocities were expressed in terms of dispersive coefficients under certain simplifying constraints. Frequency domains were found to exist around resonances where group and phase velocities are in opposition, implying possible negative index behavior. In this paper, we incorporate in the derived equations physical models (including Debye, Lorentz and Condon) for material dispersion in permittivity, permeability and chirality in order to further examine the consequences of second-order dispersion leading to negative index for practical cases, and also evaluate the resulting phase and group indices.

In this paper, effective magnetic of an arrangement of periodically close-packed conducting square rings have been studied theoretically. A non-resonant model has been introduced in order to determine the magnetic permeability of the structure from the microscopic quantities. The core of this work covers the analysis of the lattice ordering and magnetic interactions between the building blocks, i.e. a collective feature has been considered. Finally, corresponding suggestions for obtaining the lowest possible values of the magnetic permeability have been made.

We examine the coupling between resonances of closely spaced meta-atoms and investigate the role of extended effective periodicities of clusters of subwavelength sized elements on the overall bulk properties. The possibilities of negative refraction both with and without negative index, as well as the role of strong coupling near resonance on effective medium models and homogenization close to the photonic crystal limit are presented.

In this paper, we proposed the plasmonic color filters to decrease ambient light errors on active type dual band infrared image sensors for a large-area multi-touch display system. Although the strong point of the touch display system in the area of education and exhibition there are some limits of the ambient light. When an unexpected ambient light incidents into the display the touch recognition system can make errors classifying the touch point in the unexpected ambient light area. We proposed a new touch recognition image sensor system to decrease the ambient light error and investigated the optical transmission properties of plasmonic color filters for IR image sensor. To find a proper structure of the plasmonic color filters we used a commercial computer simulation tool utilizing finite-difference time-domain (FDTD) method as several thicknesses and whit the cover passivation layer or not. Gold (Au) applied for the metal film and the dispersion information associated with was derived from the Lorentz-Drude model. We also described the mechanism applied the double band filter on the IR image sensors.

Incorporation of ferromagnetic materials into metamaterial systems provides an opportunity to tune microwave permeability with an external magnetic field, strongly affecting wave propagation. We characterize microwave properties of several soft magnetic materials with high permeability as possible candidates for such applications. In the range of the ferromagnetic resonance, the permeability of ferromagnetic/dielectric composites varies from positive to negative values. In addition, a low field absorption peak provides an additional possibility of tuning with low fields. Microwave propagation through metal-dielectric multilayered systems shows

In this study, we propose a novel anisotropy modeling of the polarization dependent meta-atoms at terahertz frequencies. The proposed anisotropic metamaterials are composed of metallic microstructures combined with various numbers of Hshaped meta-atoms. We confirm that the proposed metamaterials successfully realize the unique properties that can modulate the resonance frequency for the specific polarization of an incident wave, while can keep one identical resonance frequency for its orthogonal polarization direction, simultaneously. Moreover, regardless of the number of Hshaped meta-atoms, their bandwidth can be kept identical by coupling effects between adjacent meta-atoms and their excited electric dipole moments.

Photonic crystals are one of the most remarkable metamaterials for electromagnetic waves manipulation for last decades, therefore they can be used as filters, waveguides, polarization changers, superlenses, superprisms, etc. As well today graphene has attracted considerable attention due to the unusual properties. In this paper the excitation of surface waves in the photonic crystal bounded by graphene layer was investigated for terahertz frequency range from 0.1 to 1 THz. Peaks of transmissivity in band-gaps of photonic crystal that caused by excitation of surface waves were obtained. The control of frequency position of peaks by temperature and magnetic field was demonstrated.