This PDF file contains the front matter associated with SPIE Proceedings Volume 9918, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

We show strong coupling involving three different types of resonances in plasmonic nanoarrays: surface lattice resonances, localized surface plasmon resonances on single nanoparticles, and excitations of organic dye molecules. We study spatial coherence properties of a plasmonic nanoarray covered with a dye molecule film by a double slit experiment. A continuous evolution of coherence from the weak to the strong coupling regime is observed. Finally, we show with magnetic nanoparticles how the intrinsic spin-orbit coupling of the material interplays with the symmetries of the nanoparticle array, and mention our latest results on light-matter interactions in plasmonic lattices.

In this work we present the design of a novel ophthalmic prismatic contact lens to correct for strabismus. Strabismus, colloquially called "crossed-eyes" or "wall eyes," is a condition in which the eyes are not properly aligned with each other. To our knowledge there are no contact lenses that allow for strabismus correction. To address this, we have designed a poly methyl methacrylate (PMMA) based prismatic correction contact lens. Therefore, we modeled a Fresnel lens with the appropriate optical properties and a human eye in COMSOL Multiphysics Ray Optics module. Our first design was created by mapping Fresnel lenses onto the curved surface of the eye, the focus of light on retina was suboptimal. Next we determined two more potential solutions and improved the light focus on the retina but there were still some issues. A small fraction of light (~5%) diverged and could not be focused. Due to dispersive characteristic of PMMA, chromatic aberration was present. We will use our ray optics solution and convert into a metasurface nanophotonic lens that has the identical behavior and mitigates the issues related with prismatic lens.

While typically designed to manipulate classical light, metamaterials have many potential applications for quantum optics as well. We argue why a quantum optical effective-medium theory is needed. We present such a theory for layered metamaterials that is valid for light propagation in all spatial directions, thereby generalizing earlier work for one-dimensional propagation. In contrast to classical effective-medium theory there is an additional effective parameter that describes quantum noise. Our results for metamaterials are based on a rather general Lagrangian theory for the quantum electrodynamics of media with both loss and gain. In the second part of this paper, we present a new application of transformation optics whereby local spontaneous-emission rates of quantum emitters can be designed. This follows from an analysis how electromagnetic Green functions trans- form under coordinate transformations. Spontaneous-emission rates can be either enhanced or suppressed using invisibility cloaks or gradient index lenses. Furthermore, the anisotropic material profile of the cloak enables the directional control of spontaneous emission.

In this paper, we report a computational and experimental study using tunable infrared (IR) metamaterial absorbers (MMAs) to demonstrate frequency tunable (7%) and amplitude modulation (61%) designs. The dynamic tuning of each structure was achieved through the addition of an active material—liquid crystals (LC) or vanadium dioxide (VO₂)--within the unit cell of the MMA architecture. In both systems, an applied stimulus (electric field or temperature) induced a dielectric change in the active material and subsequent variation in the absorption and reflection properties of the MMA in the mid- to long-wavelength region of the IR (MWIR and LWIR, respectively). These changes were observed to be reversible for both systems and dynamic in the LC-based structure.

To conquer Ohmic losses from metal and enhance pump absorption efficiency of a nanolaser based on surface plasmon polariton, we theoretically calculate the first magnetic and electric scattering coefficient of a dielectric sphere under a plane wave excitation with a dielectric constant of around 12. From this calculation, we could retrieve both negative effective permittivity and permeability of the sphere simultaneously at frequencies around 153 THz in the aids of Lewin’s theory and the power distribution clearly demonstrate the expected negative Goos-Hänchen effect, which usually occurred in a negative refractive waveguide, thus creating two energy vortices to trap incident energy and then promoting the pump absorption efficiency. Meanwhile, a magnetic lasing mode at 167.3 THz is demonstrated and reveals a magnetic dipole resonance mode and a circulating energy flow within the dielectric sphere, providing a possible stopped light feedback mechanism to enable the all-dielectric nanolaser. More importantly, the corresponding mode volume is reduced to 0.01λ³ and a gain threshold of 5.1×10³ is obtained. To validate our design of all-dielectric nanolaser, we employ finite-difference-time-domain simulation software to examine the behavior of the nanolaser. From simulation, we could obtain a pinned-down population inversion of 0.001 and a lasing peak at around 166.5 THz, which is very consistent with the prediction of Mie theory. Finally, according to Mie theory, we can regard the all-dielectric nanolaser as the excitation of material polariton and thus could make an analogue between lasing modes of the dielectric and metallic nanoparticles.

This paper presents an engineered metasurface which can serve functionalities such as anomalous bending, focusing, and beam shaping over the circularly polarized (CP) incident beam. The building block is a bilayer double split-loop resonators (DSLRs) where it can fully transmit the impinging light and control phase only by rotation of unit-cell and not by changing the structural parameters which can greatly facilitate the fabrication process. The mechanism behind this fascinating feature can be described as the conversion of an impinging CP incident beam into the opposite handedness and obtaining a geometrical phase shift equal to twice the rotating angle of DSLRs. It is illustrated that full transmission with 2π phase shift can be achieved with the proposed metasurface. Unique designs with helicity dependency to realize anomalous bending, bifunctional convergence/divergence, and flat-top beam creation with applying lossless beam shaping approach are presented.

We obtain local density of states (LDOS) for any nanoplasmonic system in the frequency range dominated by a localized plasmon. By including the Ohmic losses in a consistent way, we show that the plasmon LDOS is proportional to the local field intensity normalized by the absorbed power. We obtain explicit formulae for energy transfer (ET) between quantum emitters and plasmons as well as between donors and acceptors situated near a plasmonic structure. In the latter case, we find that the plasmon-assisted ET rate is proportional to the LDOS product at the donor and acceptor positions, obtain, in a general form, the plasmon ET enhancement factor, and establish the transition onset between Forster-dominated and plasmon-dominated ET regimes.

A high-sensitive polarized surface-enhanced infrared absorption (polarized SEIRA) is proposed and demonstrated by utilizing the resonant coupling of Fano-resonant mode of the asymmetric metamaterials and IR vibrational mode of a polymer nano-film. The asymmetric metamaterials consisting of an Au nano-rod pair with a coupling nano-antenna were fabricated and characterized to demonstrate the controlled Fano resonances at 1730 cm^-1, which spectrally overlapped with the C=O stretching vibrational mode. In the co-polarized SEIRA measurement, the C=O mode of the PMMA nano-film was clearly observed as a conventional anti-resonant peak within the Fano line-shape of the metamaterial. For the cross-polarized case, on the other hand, a distinctive dip appeared within a cross-polarized transmission peak of the metamaterial. Since the unwanted background is strongly suppressed in the cross-polarized detection scheme, the signal contrast was dramatically improved, allowing for the attomole detection of the C=O bond in the far-field measurement. Our metamaterial approach achieves the significant improvement of signal-to-background ratio in the far-field measurement, thus paving the way toward the high-sensitive analysis of functional group in direct IR spectroscopy.

Unidirectional edge modes are achieved in gyromagnetic photonic crystals. The physical reason is attributed to magnetic resonance and broken time-reversal symmetry under external magnetic fields. These edge modes propagate only along a single direction, while the backward modes are completely suppressed. The unidirectional transmittance is nearly 100% and hardly affected by perfect electric conductor (PEC) defect. However, a PEC defect has sensitive influence on both the phase delay and pattern distribution of unidirectional edge modes. These properties hold promise in designing various unidirectional devices. Here we design a three port circulator with high transmission contrast and magnetic controllability simultaneously.

Previous efforts to create a metamaterial lens in the microwave X band frequency range focused on the development of a device with biaxial symmetry. This allows for focusing solely along the central axis of propagation. For applications involving wave direction or energy diversion, focusing may be required off the central axis. This work explores a metamaterial device with uniaxial symmetry, namely in the direction of propagation. Ray-trace optimization and full-wave finite element simulations contribute to the design of the lens. By changing the placement of the focus, we achieve further control of the focus parameters. While the present work uses coils, the unit cell can consist of any structure or material.

The forked grating coupler (FGC) is a novel low-profile device compatible with silicon photonics that is capable of sensitive detection or efficient radiation of Optical Vortex (OV) light beams conveying orbital optical angular momentum (OAM). The FGC device combines the idea of a Bragg coupler with the forked hologram to create an integrated optics device that can selectively and efficiently couple selected optical vortex modes at near-normal incidence into planar confined dielectric waveguide modes of a photonic IC. FGCs retain many of the advantages of Bragg couplers, including convenience of placement and fabrication, reasonable bandwidth, small size, and CMOS process compatibility. In this work, prototype designs of FGC structures for 1550 nm wavelength have been developed for implementation on silicon on insulator (SOI) substrate. Fully vectorial three-dimensional (3D) electromagnetic simulation has allowed performance to be optimized over a range of structural parameters. Results have been evaluated against optical performance metrics including overall efficiency, mode match efficiency, and crosstalk between OV modes. Candidate FGC devices have been fabricated on SOI with e-beam lithography and tested optically. Tolerance to etch depth error has been evaluated.

Surface phonon polaritons (SPhPs), similar to it cousin phenomenon surface plasmon polaitons (SPPs), are quasi-neutral particles resulting from light-matter coupling that can provide high modal confinement and long propagation in the mid to long infrared (IR). Mach-Zehnder interferometer (MZI) is a combination of two connected optical directional couplers (ODC). With the use of SPhPs, sub-wavelength feature sizes and modal areas can be achieved and to this end a hybrid SPhP waveguide, where propagation length and modal area can be trade-off, will be employed in the design of an ODC and MZI. This endeavor analyzes and characteristics both an ODC and MZI using commercially available numerical simulation software employing finite element method (FEM). The ODC and MZI are design using a novel SPhP hybrid waveguide design where a 4H-SiC substrate provides the polariton mode. The output ports power and relative phase difference between ports are investigated. SPhP enhanced ODC and MZI has applications including, but not limited to, next-generation ultra-compact photonic integrated circuits and waveguide based IR sensing.

Acoustic emission method is a nondestructive evaluation method based on the propagation of elastic waves due to the sudden change in strain field caused by newly formed fracture surfaces. While the method has been successfully applied to many structures, the influence of friction emissions limits the diverse use of the method in large-scale structures. This research integrates the metamaterial geometry to block low frequency friction signals while allowing high frequency signals due to the crack growth. The phononic structure is composed of periodic arrangement of holes in a steel plate that prohibits propagation of elastic waves near the band gap of 60 kHz. The dispersion curve of the periodic structure is calculated using finite element modeling of a unit cell in COMSOL Multiphysics. As the band gap of the periodic structure is highly narrowband, the acoustic sensing is achieved by highly narrowband capacitive type Micro-Electro- Mechanical Systems (MEMS) sensors tuned to the desired stop band frequency. The integration of periodic plate design and MEMS sensors provides wave-field focusing to reduce wave attenuation, and prevent interference of secondary waves sources, such as friction, with the primary waveforms. The waveguiding feature of the designed structure is experimentally investigated and discussed in this paper.

Photodynamic therapy (PDT) is an emerging alternative treatment for various cancers and age-related macular degeneration. Phthalocyanines (Pcs) and their substituted derivatives are under intensive investigation as the second generation photosensitizers. A big challenge for the application of Pcs is poor solubility and limited accumulation in the tumor tissues, which severely reduced its PDT efficacy. Nano-delivery systems such as polymeric micelles are promising tools for increasing the solubility and improving delivery efficiency of Pcs for PDT application. In this paper, nanoparticles of amphiphilic triblock copolymer poly(L-lysine)-b-poly (ethylene glycol)-b-poly(L-lysine) were developed to encapsulate 1-2 generation carboxylic poly (benzyl aryl ether) dendrimer. The morphologies and photophysical properties of polymeric nanoparticles loaded with 1-2 generation dendritic phthalocyanines (G1-ZnPc(COOH)8/m and G2-ZnPc(COOH)16/m) were studied by AFM, UV/Vis and fluorescent spectroscopic method. The morphologies of self-assembled PLL-PEG-PLL aggregates exhibited concentration dependence. Its morphologies changed from cocoon-like to spheral. The diameters of G1-ZnPc(COOH)8/m and G2-ZnPc(COOH)16/m were in the range of 33-147 nm, increasing with the increase of the concentration of PLL-PEG-PLL. The morphologies of G2-ZnPc(COOH)16/m also changed from cocoon-like to sphere with the increase of the concentration of PLL-PEG-PLL. It was found that, the no obviously Q change was observed between the free phthalocyanines and nanoparticles. The fluorescence intensity of polymer nanoparticles were higher enhanced compared with free dendritic phthalocyanines. The dendrimer phthalocyanine loaded with poly(L-lysine)-b-poly (ethylene glycol)-b-poly(L-lysine) presented suitable physical stability, improved photophysical properties suggesting it may be considered as a promising formulation for PDT.

Transformation optics provides a geometry-based tool to create new components taking advantage of artificial metamaterials with optical properties that are not available in nature. Unfortunately, although guided electromagnetic waves are crucial for optical circuitry, transformation optics is not yet compatible with two-dimensional slab waveguides. Indeed, after determining the propagation of confined waves along the waveguide with a two-dimensional coordinate transformation, the conventional application of transformation optics results in metamaterials whose properties are insensitive to the coordinate perpendicular to the waveguide, leading to bulky, and therefore impractical, designs. In this contribution, we formulate an alternative framework that leads to feasible coordinate-based designs of two-dimensional waveguides. To this end, we characterize a guided transverse-magnetic light mode by relevant electromagnetic equations: a Helmholtz equation to account for wave propagation and a dispersion relation to impose a continuous light profile at the interface. By considering how two-dimensional conformal transformations transform these equations, we are able to materialize the coordinate-designed flows with a nonmagnetic metamaterial core of varying thickness, obtaining a two-dimensional device. We numerically demonstrate the effectiveness and versatility of our equivalence relations with three crucial functionalities, a beam bender, a beam splitter and a conformal lens, on a qualitative and quantitative level, by respectively comparing the electromagnetic fields inside and the transmission of our two-dimensional metamaterial devices to that of their three-dimensional counterparts at telecom wavelengths. As a result, we envision that one coordinate-based multifunctional waveguide component may seamlessly split and bend light beams on the landscape of an optical chip.

The Berreman matrix method is used to analyze the polarization and propagation of electromagnetic waves and beams in anisotropic metamaterials. The metamaterial, comprising a multilayer structure of alternating metal and dielectric layers, is modeled as an effective anisotropic medium. The Maxwell’s equations for electromagnetic propagation are then represented as a set of coupled differential equations using the Berreman matrix. These coupled equations are then solved analytically and cross checked numerically using MATLAB® for plane wave propagation. The analysis can be extended to Gaussian beam propagation through such anisotropic metamaterials using the angular plane wave spectral approach.

The propagation properties of 1D waveguides composed by a dielectric core and a multilayered metallic dielectric cladding are numerically analyzed in details for applications covering the O-E-S-C-L-U optical communication bands. The propagation length, penetration depth and the figure of merit as a function of their geometrical and optical parameters are presented. The strong dependence of their properties with their constituent materials has been observed. Long propagation distances with high values of figure of merit can be obtained, opening the possibility to develop devices of high performance in the optical band under inspection.

We propose and discuss high-Q reconfigurable metamaterials based on graphene. The key components of the device are periodic concentric metallic ring resonators with interdigitated fingers, which are placed in-between the rings and provide for the large Q in the metamaterial, as well as several strategically located gaps where active graphene sheets are placed. We can easily adjust the frequency response of the metamaterial by means of varying a couple of parameters, such as the ring dimensions, number of fingers, etc., but also dynamically by means of varying conductivity in graphene.

The optical excitation of high-order plasmonic resonant modes in nanostructures is important for the enhancement of light-matter interactions at the nanoscale. Due to the fast spatial variation of the electromagnetic field distribution associated with high-order modes, their excitation by conventional optical methods is extremely challenging. Here we describe a novel nonlinear scheme devised to access high-order plasmonic resonances. The proposed method is based on the temporal modulation of the permittivity of the medium surrounding a plasmonic nanoparticle. Analytical results are presented for the case of spherical nanoparticle demonstrating the effectiveness of the proposed method.

In this paper we discuss the role of evanescent waves in nanophotonic devices, especially in metamaterials. We discuss how metamaterial cladding increases the power confinement in waveguides by increasing the momentum of evanescent waves. The momentum of evanescent waves is controlled in such a fashion that condition of total internal reflection is not disturbed. This becomes possible by making the cladding anisotropic. Anisotropic cladding gives the facility to control the parallel and perpendicular components of wave vector individually. We analyze the efficiency of this technique in case of waveguides. We have also discussed the advantages of collecting evanescent waves for imaging sub wavelength objects.

The objective-first inverse-design algorithm is used to design an ultra-compact all-dielectric optical diode. Based on silicon and air only, this optical diode relies on asymmetric spatial mode conversion between the left and right ports. The first even mode incident from the left port is transmitted to the right port after being converted into an odd mode. On the other hand, same mode incident from the right port is reflected back by the optical diode dielectric structure. The convergence and performance of the algorithm are studied, along with a transform method that converts continuous permittivity medium into a binary material design. The optimal device is studied with full electromagnetic simulations to compare its behavior under right and left incidences, in 2D and 3D settings as well. A broadband optical diode is reported with a large ratio between the two transmission directions. This illustrates the potential of the objective-first inverse-design method to design ultra-compact broadband photonic devices.

The transmittance, reflectance and absorption of silver nanowires metamaterial embedded into a semiconductor matrix with optical gain are numerically investigated. Metamaterials may suffer from appreciable dissipative losses which are inherent for all plasmonic structures. The losses can significantly be reduced by introducing optical gain in the dielectric matrix by placing atomic or molecular impurities which are pumped by an external light source to create a population inversion. We numerically analyzed the optical properties when the semiconductor host material represents a gain medium. We calculate the transmittance, reflectance and absorption at normal incidence in the visible and near infrared ranges. We observed a peculiar behavior of their optical coefficients that can be explained by observing the field redistribution on the metamaterial.

It has been demonstrated by many theoretical and experimentals works that Mie resonances are at the heart of the effective properties of dielectric metamaterials. These resonances indeed allow for the onset of tailorable macroscopic magnetic properties. They were shown to provide a convenient way to study the transition between photonic crystals and metamaterials. In the present work, we show that the band structure linked to theses resonances is largely scale invariant and also, to some extend, robust with regard to disorder. These results do not rely heavily on a specific type of wave, suggesting that the same kind of results can be obtained for acoustic or gravity waves.

We study, theoretically, omni-directional Euclidean transformation-optics (TO) devices comprising planar, light-ray-direction changing, imaging, interfaces. We initially studied such devices in the case when the interfaces are homogeneous, showing that very general transformations between physical and electromagnetic space are possible. We are now studying the case of inhomogeneous interfaces. This case is more complex to analyse, but the inhomogeneous interfaces include ideal thin lenses, which gives rise to the hope that it might be possible to construct practical omni-directional TO devices from lenses alone. Here we report on our progress in this direction.

This paper presents an investigation of terajets formation by dielectric periodic structure at terahertz frequencies in effective medium regime (photonic metamaterial). The dispersions of effective permittivity for three periodic structures formed by different types of plastics (ABS, PLA, Crystal) were analytically obtained for both regimes. Numerical simulation of this structure was performed by using COMSOL Multiphysics. The terajet formation was numerically shown.