This PDF file contains the front matter associated with SPIE Proceedings Volume 9502, including the Title Page, Copyright information, Table of Contents, Invited Panel Discussion, and Conference Committee listing.

We review a new, rapidly developing field of all-dielectric nanophotonics which allows to control both magnetic and electric response of structured matter by engineering the Mie resonances in high-index dielectric nanoparticles. We discuss optical properties of such dielectric nanoparticles, methods of their fabrication, and also recent advances in all-dielectric metadevices including couple-resonator dielectric waveguides, nanoantennas, and metasurfaces.

Here we present both an overview of different nonlinear optical phenomena occurring in nanopatterned materials and new results on the symmetry induced second harmonic generation (SHG) signal from metallic nanowires. A discussion about symmetry breaking in artificial chiral metamaterials is presented, while the experimental evidence was given by second order nonlinear optical measurements on different samples. Here, new SHG measurements on regular array of tilted nanowires (NWs) produced by grazing evaporating gold on a silicon substrate were presented and discussed. The surface composed by tilted wires can induce an optical chiral response of the whole sample when the light impinges on the sample on an out-of-normal incidence angle (extrinsic chirality). The measurements were performed by using circular polarised laser excitation at the wavelength of 800nm and by observing the second harmonic response at the wavelength of 400nm in different polarization states. The second harmonic generation process results to be very sensitive to the symmetry breaking at the interfaces of investigated samples.

In photovoltaic devices, metal nanoparticles embedded in a semiconductor layer allow the enhancement of solar-toelectric energy conversion efficiency due to enhanced light absorption via a prolonged optical path, enhanced electric fields near the metallic inclusions, direct injection of hot electrons, or local heating. Here we pursue the first two avenues. In the first, light scattered at an angle beyond the critical angle for reflection is coupled into the semiconductor layer and confined within such planar waveguide up to possible exciton generation. In the second, light is trapped by the excitation of localized surface plasmons on metal nanoparticles leading to enhanced near-field plasmon-exciton coupling at the peak of the plasmon resonance. We report on results of a numerical experiment on light absorption in polymer- (fullerene derivative) blends, using the 3D FDTD method, where exact optical parameters of the materials involved are taken from our recent measurements. In simulations we investigate light absorption in randomly distributed metal nanoparticles dispersed in polyazomethine-(fullerene derivative) blends, which serve as active layers in bulkheterojunction polymer solar cells. In the study Ag and Al nanoparticles of different diameters and fill factors are diffused in two air-stable aromatic polyazomethines with different chemical structures (abbreviated S9POF and S15POF) mixed with phenyl-C₆₁-butyric acid methyl ester (PCBM) or [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM). The mixtures are spin coated on a 100 nm thick Al layer deposited on a fused silica substrate. Optical constants of the active layers are taken from spectroscopic ellipsometry and reflectance measurements using a rotating analyzer type ellipsometer with auto-retarder performed in the wavelength range from 225 nm to 2200 nm. The permittivities of Ag and Al particles of diameters from 20 to 60 nm are assumed to be equal to those measured on 100 to 200 nm thick metal films.

Interaction of light with metals in the form of surface plasmons is used in a wide range of applications in which the scattering decay channel is important. The absorption channel is usually thought of as unwanted and detrimental to the efficiency of the device. This is true in many applications, however, recent studies have shown that maximization of the decay channel of surface plasmons has potentially significant uses. One of these is the creation of electron-hole pairs or hot electrons which can be used for e.g. catalysis. Here, we study the optical properties of hetero-metallic nanostructures that enhance light interaction with the catalytic elements of the nanostructures. A hybridized LSPR that matches the spectral characteristic of the light source is excited. This LSPR through coupling between the plasmonic elements maximizes light absorption in the catalytic part of the nanostructure. Numerically calculated visible light absorption in the catalytic nanoparticles is enhanced 12-fold for large catalytic disks and by more 30 for small nanoparticles on the order of 5 nm. In experiments we measure a sizable increase in the absorption cross section when small palladium nanoparticles are coupled to a large silver resonator. These observations suggest that heterometallic nanostructures can enhance catalytic reaction rates.

We describe the treatment of thin conductive sheets within the Discontinuous Galerkin Time-Domain (DGTD) method for solving the Maxwell equations and apply this approach to the efficient computation of the optical properties of graphene-based systems. In particular, we show that a thin conductive sheet can be handled by incorporating the associated jump conditions of the electromagnetic field into the numerical flux of the DGTD approach. This results in a flexible and efficient numerical scheme that can be applied to a number of systems. Specifically, we show how to treat individual graphene sheets on substrates as well as finite stacks of alternating graphene and dielectric layers by modeling the dispersive and dissipative properties of graphene via a two-term critical-point model for its electrostatically doped conductivity.

Broadband layered absorbers are analysed theoretically and experimentally. A genetic algorithm is used to opti- mize broadband and wide-angle of incidence metal-dielectric layered absorbers. An approximate representation of the perfectly matched layer with a spatially varied absorption strength is discussed. The PML is realised as a stack of uniform and isotropic metamaterial layers with permittivieties and permeabilities given from the effective medium theory. This approximate representation of PML is based on the effective medium theory and we call it an effective medium PML (EM-PML).1 We compare the re ection properties of the layered absorbers to that of a PML material and demonstrate that after neglecting gain and magnetic properties, the absorber remains functional.

We explore the plasmonic interactions among multiple localized plasmon modes in isolated dimers as well as in their periodic arrays by means of quasi-analytical models. A model based on dipolar approximation was developed for that purpose and extended to periodic array of particles using coupled dipole approximation technique. In order to capture the modes coupling at shorter distances, with the use of the plasmon hybridization theory, we applied its formalism to dimer structures and studied the plasmonic resonances as a function of particle mutual distance. All models predictions are compared with rigorously computed data.

We demonstrate experimentally that plasmonic nanoantennas made of metal-insulator-metal ribbons can be used to tailor the spectral emissivity of a gold surface in the infrared. Two areas of a gold mirror sample were covered with various combinations of nanoantennas. Their emissivity was characterized thanks to a dedicated bench, based on the combination of a Fourier transform spectrometer and a microbolometer infrared camera. A near unity polarized emission on two distinct infrared bands is obtained on the respective two areas, which is coherent with theoretical predictions.

Electromagnetic surface waves, analogous to the classic surface plasmons can be supported to any interface, providing that the effective permittivity have an opposite sign. Localized plasmonlike modes and guided mode resonances are established in a photonic crystal slab irradiated with out-of-plane incident radiation, making photonic crystals a very appealing alternative to plasmonic substrates, avoiding the limits of absorption losses in metals.

Microwave negative index metamaterials have been recently characterized by using primarily far-field transmission of flat slabs and wedges to determine transmission losses and index of refraction, respectively. Although these methods are adequate for most purposes, a more complete characterization of spatial transmission is useful to analyze metamaterials in 3-D, for examples, to characterize irregular forms of metamaterials, such as gradients, prisms, and conformal surfaces. We report here the infrared imaging of the transmitted intensity of microwave electromagnetic waves through a prism of the negative index metamaterials.

The effects of two different type of asymmetric nano-antenna that produce distinct resonance peaks were experimentally and numerically observed. At mid-infrared wavelengths broad resonances based upon various metamaterials structures have been previously reported. Here we show that introducing a crossbar on vertical asymmetric dipole nano-antenna can produce narrower resonance peaks than the dipole alone. Our approach to investigating different asymmetric nanoantenna structures yielded quality factor values more than twice the existing values reported within this region of the electromagnetic spectrum.

Femtosecond Faraday rotation evolution and a propagation of a femtosecond pulse through a thin magnetic films is calculated and measured.

Here we present a general approach for describing the physics of Fano resonances in nanoparticle oligomers. It is shown that the interference of nonorthogonal collective eigenmodes is a sufficient condition to produce Fano resonances. We then show that such nonorthogonality between eigenmodes also permits the existence of a new form circular dichroism in the absorption and scattering cross-sections, even when circular dichroism is forbidden in the extinction cross-section.

We investigated the interaction of a periodically patterned columnar thin film (PP-CTF) of silver with light incident on it from a vacuous half space, as a function of the angle ψ between the plane of incidence and the morphologically significant plane of the PP-CTF. The chosen structure had previously been shown to be capable of showing asymmetric coupling of surface-plasmon-polariton (SPP) waves over a broad bandwidth in the visible regime with incident light when the plane of incidence coincides with the morphologically significant plane of the PP-CTF ( ψ = 0°). We determined experimentally that coupling may be completely symmetric in some spectral regime, when the plane of incidence is orthogonal to the morphologically significant plane of the PP- CTF ( ψ = 90°). Whereas asymmetric coupling occurs with quasilinear dispersion when ψ = 0°, completely symmetric coupling occurs with quasiparabolic dispersion.

The existence of a special type of resonances in the visible transmission spectrum of a very thin two-dimensional photonic crystal slab is demonstrated. We illustrate a controlling mechanism that allows the stabilization of the field amplification in a thin layer lattice with low contrast dielectric. Numerical simulations show that an extremely large field enhancement, as large as 700 times the amplitude of the incident wave, connected with high Q-factor resonances can be axcited. The connection with the bound states in continuum phenomenon is highlighted.

The ability to control the polarization state of an electromagnetic wave thanks to plasmonic metasurfaces is at the core of many various applications. We demonstrate both theoretically and experimentally that plasmonic planar L-shaped antennas can induce a 90°-rotation of the linear polarization of light with a nearly total efficiency in the mid-wavelength infrared. Then, we generalize these results with V-shaped antennas that can induce any rotation of the linear polarization by engineering the in-plane geometry of the antenna.

Extraordinary/Enhanced optical transmission (EOT) is studied in the realization of plasmonic based filters in the visible range and near infrared spectrum for the purpose of substituting the Bayer-pattern filter with a new CMOS-compatible filter which can be easily tuned to provide different filter spectra. The filters studied in this paper are based on nano-structured 150nm thick Aluminum (Al) layer sandwiched between silicon dioxide (SiO₂) layers. The resonance wavelengths achieved by the filters are at 700nm and 950 nm. Three parameters are used for tuning the two filters, i.e., aperture area, the period, and the holes arrangement (square or rhombic lattice). The filter is based on the principle of surface plasmon polaritons (SPPs), where the electromagnetic waves of the incident light couples with the free charges of the metal at the metal-dielectric interface. EOT is observed when the metal is structured with apertures such as rectangular, circular, cross, bowtie, etc. The resonance frequency in that case depends on the shape of the aperture, material used, the size of the apertures, the period of the array, and the surrounding material. The fabricated two filters show EOT at wavelengths as designed and simulated with blueshift in the peak location.

We present experimental results on angle-dependent microwave response of the double negative microwave metamaterials. Polarization and angle-dependent transmission spectra of two microwave negative index metamaterials were measured. Two sets of S-shape single unit cells were designed for the 12.5 GHz and 20 GHz frequency ranges. Transmission spectra were measured as a function of polarization and incidence angles of the incoming electromagnetic waves.

Theoretical study of light management in thin film organic photovoltaic cell that utilizes diffraction coupling to guided waves is presented. As a model system, a regular solar cell geometry with P3HT:PCBM active layer, transparent ITO electrode and Al backside electrode is used. The paper discusses enhancement of absorption of incident photons selectively in the active layer by the interplay of surface plasmon polariton and optical waveguide waves, the effect on the profile of their field and damping that affects the spatial distribution of dissipated light energy in the layer structure. The model shows that for optimized grating period and modulation depth the number of absorbed photons in the active layer can be increased by 24 per cent. The comparison of the geometry with conformal and non-conformally corrugated layers reveals that the conformal structure outperforms the non-conformal in the enhancing of photon absorption in the wavelength range of 350-800 nm.

This contribution demonstrates surface modification of thin photoresist layers and polydimethylsiloxane (PDMS) surfaces with spatial resolution better than 20 nm. We provided few different 2D arrangements of surface patterning with aim to prepare 2D photonic structures with various symmetries in the thin S1828 photoresist layer using AFM lithography. Consequently, we used the imprinting technique for transferring the photoresist pattern to the PDMS membrane surface. Finally, prepared 2D photonic structures in photoresist and PDMS surfaces are characterized by AFM.

Metamaterials are being increasingly used as highly sensitive detection devices. The design of these structures and the ability to effect changes in response through small changes in the geometry of their constituent elements allow for the enhancement of known analysis techniques such as infrared or Raman spectroscopy. High electromagnetic fields have been shown to occur in features such as small gaps and sharp tips and these so called “hot-spots” are the main focus of recent work in Surface Enhanced Raman Spectroscopy (SERS). Previous work has shown dipole pairs with small gaps between them to be suitable for the SERS detection of very small amounts of organic compounds. The main difficulties lie in the small dimensions (≤100 nm) necessary to attain a significant response at the typical Raman pump wavelengths. Also the small size of the gaps is a challenge when it comes to prevent “bridging” between the structures during the fabrication process. In this work we show, through simulations, that carefully controlling the length of dipolar structures as well as the gap between these dipoles a resonant response can be achieved close to the pump Raman wavelengths. Also, we see that increasing the width of the dipole pair shifts the resonant peaks to longer wavelengths. By optimizing their geometry, more efficient and easier to fabricate structures can be used as environmental organic sensors.

We have investigated the effect of concentric circles geometry on the performance of focusing plasmonic circular grating (PCG)-coupled surface-omnidirectional absorption. We wish to highlight the essential characteristics of plasmonic circular grating nanostructure to assist researchers in developing and advancing suitable organic solar cells (OSC) for unique applications. Exactly how plasmonic enhancement and the absorption characteristics of the organic materials (P3HT:PCBM and PEDOT:PSS) interact with each other is also examined. We present experimental studies of broadband absorption enhancement in PCG structure. We show that the PCG structure can result in broadband absorption enhancement, the overall optical absorption in organic film can be greatly enhanced up to ~111.2 % compared to the planar device without grating.

In this paper, we're binding gold nanoparticles (GNPs) and reduced graphene oxide (rGO) by cystamine (Cys). The PEDOT:PSS mix GNPs/Cys/rGO as a hole transport layer of the solar cell. From the experimental result shows the PEDOT:PSS/GNPs/Cys/rGO/ITO film than ITO film have the best transmittance. It's transmittance was decreased for 1.01% at 545 nm wavelength. The sheet resistance of PEDOT:PSS/GNPs/Cys/rGO/ITO was reduce than PEDOT:PSS/ITO, when it was doped with Gold nanoparticles (GNPs) and rGO on ITO glass. The former is than the latter decreased for 1%. For these reasons due to impact by surface doping of composite plasmonic material.

Dispersions of absorption coefficient μ_a, complex refractive index n, complex permittivity e and penetration depth δ of CdSe quantum dots were experimentally obtained in terahertz frequency range of 0.1-1 THz. The possibility of optical properties control by quantum dots sizes and temperature treatment was shown.

A measurable magneto-optical activity of nanoparticles made out of noble metals is observed when the localized plasmon waves are excited in the presence of external magnetic field. We confirmed these observations for quite general Au nanostructure on SiO2/Si substrate theoretically and by experimental way. The heterogeneous layer is formed as a field of cylindrical or spheroidal nanodots of various size having the same height and parallel symmetry axis. These properties enable to apply the Bruggeman’s model of effective medium approximation, for which the size of dots (height, diameter) and fill-factor of nanodots were specified using the transmission electron microscopy image processing. Actually, this model is extended about the interaction of magnetic dipole moments simulated using discrete dipole approximation via geometrical averaging. Derived computational algorithm leads to better agreement with experimental data in the form of Kerr angles in polar configuration at visible spectral region. Obtained out-puts also illustrate the fact that extinction peak of plasmon excitation is located at the resonance wavelength of permittivity.