This PDF file contains the front matter associated with SPIE Proceedings Volume 11802, including the Title Page, Copyright information, and Table of Contents.

Grating-coupled excitation of surface plasmon-polariton waves guided by the interface of a metal and an anisotropic dielectric material evinces morphological effects arising from the divergence of structural anisotropy (grating) from constitutive anisotropy (dielectric material). Even if the metal is replaced by an isotropic dielectric ma- terial, the same effects are seen in the excitation of Dyakonov surface waves. The morphological effects vanish with constitutive anisotropy, as exemplified with a columnar thin film (CTF) as the dielectric material. Both p-polarized and s-polarized incident plane waves can excite the surface plasmon-polariton (SPP) waves as well as Dyakonov surface waves, provided that either the plane of incidence and/or the morphologically significant plane of the CTF do not coincide with the grating plane.

Photodetectors harnessing hot carrier generation on surface plasmon resonant nanoantennas are a promising avenue to achieving sub-bandgap imaging at room temperature. However, efficient extraction of plasmonic hot carriers under low-energy infrared (IR) excitation predicates careful design of Schottky interfaces. This work reports on the simulation-guided fabrication of Au (i) planar diodes and (ii) embedded IR nanoantennas interfaced with both n-/p-type Si and GaAs semiconductors in order to elucidate the impact of their electronic properties on photocurrent generation.

We analyze the 3D structure of a 120×38 nm disc-shaped region of a PbSe QD epi-SL using full-tilt high-angle annular dark-field electron tomography. The high spatial resolution enables determination of the center-of-mass coordinates of all 1846 QDs in the sample as well as the size and shape of the thousands of epitaxial connections (necks) between the QDs. A map of the neck network is used to quantify relationships between neck number (the number of necks each QD possesses), average neck diameter, QD location in the film, and the nearest neighbor inter-QD distance and distance distribution. An electronic model demonstrates how neck distribution and SL defects reduce charge mobility.

We fabricated the various nano-aperture plasmonic platforms on pyramid and on the flat membranes. The nano-apertures such as circular nanopore and nanoslit pores were fabricated. Optical characteristics were found to be dependent upon the aperture size and the sample thickness. The enhanced optical emission spectra with decreased aperture sizes have been observed due to spp-mediated emission at ~ 500 nm. In addition, the broad emission spectra in the visible and infrared region from the nanoslit array are obtained. The fabricated Au nano-aperture platform with a few nano-meter openings can be utilized as a single-molecule sensor.

Large-area nano-patterned surfaces invoking hydrophobicity hold great significance for Surface Enhanced RamanSpectroscopy or SERS substrates. Conventionally, these structures are fabricated using state-of-the-art litho-graphic techniques. These techniques while being efficient, are complex and are cost-ineffective. Here, we report a low-cost, facile and scalable solution for fabrication of periodic array of metallic nanocones using colloidal lithography and reactive ion etching process. Nanocone array coated with gold thin film serves as a hydrophobicsurface with plasmonic properties. Hydrophobicity on the cones helps to keep the analyte molecule localized near the tip of nanocones where, due to plasmonic behavior of metal thin film i.e. field enhancement by the metal gives rise to significant SERS. We validate this concept through our fabricated substrate via detection ofRhodamine 6G molecules using Raman spectroscopy and report the limit of detection upto 1 nM.

We propose quad-layered transmissive structural color filters that can generate RGB primary colors with high purity and high brightness by utilizing interferences in dual Fabry-Perot (FP) cavities. Since there is a trade-off between color purity and brightness in a conventional single FP cavity, a peak separation in multiple FP cavities is exploited to achieve a more square-shaped spectral curve. Besides, controlling a resonance order in each cavity leads to a great suppression of a higher-order resonance for a red color filter. The presented results may be applied to various applications including display panels, decorations, and image sensors.

We report a one-dimensional (1D) planar topological laser, based on a topological interface state formed when two 1D photonic crystals with overlapping band gaps are brought into contact. We use a planar binary structure and achieve an interface state in the visible spectral region. The unit cell of each crystal is composed of two dielectric materials A and B with different refractive indices. A topological Zak phase can be ascribed to the photonic bands for such 1D crystals. The Zak phase depends on thicknesses ratio of these two materials d_A⁄d_B while the optical length of the unit cell remains constant. We incorporate a thin layer of an active organic material into the resonant structure, providing gain under an optical excitation and lasing under sufficiently strong pump energy density was observed. We show that the topological nature of the interface state leads to a topological protection i.e. stability against layer thickness ratio variations.

Fabrication and scaling of disordered hyperuniform (dHU) materials remain hampered by the difficulties in controlling the spontaneous phenomena leading to this novel kind of exotic arrangement of objects. In this work, we demonstrate a hybrid top-down/bottom-up approach based on sol-gel dip-coating and nano-imprint lithography for the faithful reproduction of dHU metasurfaces in metal oxides (MOx). Nano- to micro-structures made of silica and titania can be directly printed over several cm2 on glass and on silicon substrates. Firstly, we describe the polymer mold fabrication starting from a hard master obtained via spontaneous solid-state dewetting. Then we address the effective dHU character of the master and of the replica and the role of the initial thickness of the sol-gel layer on the MOx replicas. Finally, these structures will be optimized towards their exploitation in many potential photonic applications like photonic devices (anti-reflection coatings, quantum emitters).

Optical metasurfaces are designed to control light similarly to conventional refractive optics, but with considerably less size and weight. They manipulate light based on the designed scattering from subwavelength resonant nanostructures within the surface. Such devices have only recently been fabricated. We characterized the performance of a 4-cm-focallength infrared dielectric metasurface lens using a scanning InSb detector array to record the intensity field behind the lens through its focal point and an optical scatterometer to measure its scatter. For the scatter measurements, a 5-mm-diameter beam illuminated a subsection of the metasurface at ten locations across the 40-mm extent of the lens to evaluate scattering in each subsection. The affected beam was steered through the lens’ focal point and expanded beyond it due to the 50-cm length of the scatterometer’s measurement arm. In general, the metasurface had scattering “shoulders” at angles outside the intended focal area about 2 orders of magnitude in transmission distribution space (Sr-1) higher than those of either a comparable infrared refractive optic or a flat polished silicon substrate; an additional forward-scattering lobe and a colinear peak caused by light travelling through the metasurface unaffected, which are not typically observed in a refractive lens, were also observed.

Significant research has been done to develop functional bio-inspired nano-architectures for photonic, biomedical and energy storage applications. Among these, peptide nanostructures are the prime candidates with unique optical properties, like the wide optical transparency, high refractive index contrast, and optical nonlinearity. In this work, a linear aromatic diphenylalanine peptide, which is the core motif of Alzheimer-amyloid protein, is self-assembled into open-end hexagonal microtubes. The waveguiding aspects of the tubes are studied with high NA objectives acting as a major optical component to couple light into one of the ends of the tubes. Our study tells that the micro-waveguide’s performance with chromatically aberrated i.e uncorrected objective is far better than the corrected one giving a higher dynamical range, higher signal-to-noise ratio, and higher guided peak resolution, thus making it more suitable for fine measurements. The experimental results are verified using the finite difference time domain method. The higher resolution, higher scan depth, and color selectivity with the aberrated objectives indicate deploying these waveguides in biosensing and other applications.

In this work we propose a new type of symmetrical surface relief diffractive grating for waveguide -based Augmented Reality near-eye display system with a wide Field of View (FoV). We demonstrate that by using a dual-mode symmetrical in-coupling system and angular pupil tiling, we can extend the overall horizontal FoV. Our grating coupler is optimized for the second diffraction orders. The proposed concept is validated numerically via full-wave electromagnetic analysis of a 1D diffraction grating. Measurements of the diffraction efficiency of the micro-fabricated prototype are compared with the results of the numerical simulation.

We propose a new mechanism for fully optical tuning and self-stabilization of microresonators based on optical fibers. We suggest using a fiber with core doped with rare earth active ions. Launching light into the core would result in heating and tuning the microcavity. We also show that utilizing a single laser for both pumping the micro-resonator and heating up the fibre creates a feedback for self-stabilization of the microcavity.

Polaritons in 2D materials have been extensively studied over the past decade due to their fundamental interest and as a platform for applications in telecommunications and sensing. We quantify the coupling strength between light and 2D polaritons in thin films, using point and line scatterers, and find universal constraints that limit its fundamental maximum allowed values.

Plasmons propagating in 1-D graphene nanoribbons are studied by employing precise quantum-mechanical calculations that account for the quantum finite-size, edge-termination, and nonlocal effects in the optical response. Our calculations indicate a strong dependence on such phenomena for excitation with a high optical momentum component along the direction of transverse symmetry in both linear and nonlinear optical response. Particularly, second-order processes are found to yield a high efficiency owing to the breaking of inversion symmetry. We seek to profit from such phenomena and motivate the application of graphene nanostructures towards actively-tunable plasmonic conduits in nanophotonic circuitry.

We develop a closed-loop solution to design, to optimize and to expansively fabricate the desirable quasi-random nanostructures(QRNs). In contrast to the current non-deterministic manufacturing process that cannot be deployed in large dimensionality, we innovatively import binary quasi-random sequences to generate QRNs deterministically without the restriction of the pattern size. Note that all 2D quasi-random patterns such as particle and channel types can also be converted into binary sequences by digitizing their 2D pattern images. Moreover, to bridge the gap between the nanostructure spatial arrangement and its optical performance, the star discrepancy calculation is employed as a guidance to evaluate and to optimize these binary QNRs given that the nanostructures’ uniformity is a key factor for light trapping. Finally, these binary QRNs are generated in a “pit-and-land” morphology so that they can be facilely and directly fabricated via optical disk recording technology.

The current standard for communications system on satellites are high size, weight, and power (SWaP) RF transceivers, which is contrasted with the low SWaP solar arrays that implement III-V semiconductors for optimal solar collection. An alternative, low SWaP solution is to implement a hybrid photovoltaic (PV)/electroabsorptive modulator (EAM) coupled with a retroreflector and use free space optical communication over 1.55 μm rather than RF communication. A design which minimizes parasitic losses and optimizes contrast ratio and cutoff frequency in a 1 cm2 device is discussed.

The polymer nanocomposites have attracted increasing attention in the optical components that are miniaturized and integrated with wearable or portable electronics due to the polymer processibility and the tunability of the refractive index (RI) by adding nanoparticles. However, the lack of models predicting the composites’ RI attributed to the morphology, physical properties, as well as volume fraction of the nanoparticles poses difficulties in the design. This study investigates the effect of the size and agglomeration condition of the nanoparticles on the effective RI based on a Finite Element Analysis (FEA) method simulating the Fabry-Pérot resonance within the composite film. The result showed that larger particles (or particle clusters) could reinforce the RI of nanocomposites compared with the well-dispersed small particles. The particle-cluster model had lower RI than the single-solid-particle model with the same effective particle diameter, demonstrating that the particle cluster provides less scattering intensity than the single-solid-particle.

In this paper, we propose a new sensing topology based on a differential power analysis, using an array of photonic sensors. The system structure is composed of a 1x4 balanced power divider, three Bragg gratings, and a reference branch. In particular, we present an analysis of the individual sensing parameters of the Bragg gratings, as well as the procedure to be followed in order to optimise the design parameters of the sensing system. The designs were verified with simulations by different numerical methods. Finally, a substantial reduction of the detection limit is demonstrated by easy-to-implement signal post-processing.

In this work we introduce a new approach to fabricate under SiN platform a small foot print power splitter. The proposed strategy of design is based on the well-known simplified coherent coupling. The sensibility of design parameters are also analyzed and discussed in this paper. By this approach very compact device can be designed and it opens a new avenue to improve and enhance the performance of integrated devices developed under silicon nitride scheme.

The article deals with the results of the study focused on the pattern of the distribution of heat flows in the cutting wedge of a carbide tool during the turning of steel. The influence of the wear-resistant TiN, (TiAlCr)N, and (AlTiCr)N coatings on the thermal state of the tool has been investigated. The results of the mathematical modeling have been compared with the data obtained by a method that relates the temperature in the cutting wedge of the tool to the changes in the microstructure and hardness of the material (the Wright and Trent methods). The experimental studies of tool life of the tools with the coatings under study and uncoated tools were carried out during the turning of AISI 5135 steel. It has been found that a tool with the (AlTiCr)N coating has the longest tool life which may be associated with a rational distribution of heat flows in the cutting zone and the cutting wedge of the tool. The use of self-organising wear-resistant coatings reduces the level of temperatures in the cutting zone by 8-20%.

We present a new proposal for enhancing the transverse magneto-optical Kerr effect (TMOKE) in the transmission mode using dielectric magneto-optical (MO) ribs deposited on a high-refractive-index (HRI) slab. Our concept is based on the phase-matching condition between the MO grating and the slab to produce extraordinary TMOKE amplitudes, which are superior to the most successful plasmonic approaches, and at least one order of magnitude higher than using dielectric MO gratings. It is also significant that there was almost no loss in the structure proposed owing to the low level of losses from the constituent materials. These features can be exploited in sensing and biosensing, as we demonstrated by considering the nanostructure in a typical liquid medium.

This paper discusses a new complex approach and an example of its practical application to solve the problem of improving the precision ceramics products and parts operational performance (ensuring high operational stability). The proposed approach consists of forming micro-texture in a ceramic product surface layer through vacuum-plasma deposition of conductive nanocomposite coatings based on a multicomponent thermally stable nitrides Ti-Al-Cr system as an auxiliary electrode in electrical discharge machining such as forming a specific microtexture in the surface layer, e.g., a combination of cavities, grooves, etc. This approach considerably improves the ceramic product surface layer characteristics, reduces contact surfaces' "ceramic product – counter face" adhesion and friction intensity, and ensures increased wear resistance and ceramic product operability.

We present dual-cavity based reflective structural color filters that can produce RGB additive colors featuring high purity and high efficiency. We decided to design a filter with a new wavelength by combining two classical MDM structure Fabry-Perot cavities with different resonant wavelength. A cavity medium with high refractive index leads to angle-invariant performance up to 50˚. Moreover, only deposition is involved so that the device can be easily scaled over a large area. The described approach may provide new avenues for various applications, such as reflective displays and surface coatings for decoration and solar cells.

The research aims to investigate the effect of depositing nitride and Si-containing amorphous hydrogenated carbon films on the characteristics of SiAlON-based ceramics experimentally. The effect of TiN/(Ti,Al)N, (Cr,Al,Si)N and (Cr,Al,Si)N/a-C:H:Si coatings on the microrelief and surface defects of ceramics was studied. The nanohardness, plasticity, and coefficient of friction of the ceramic material at room temperature and under heating conditions after applying the mentioned coatings were quantified. Laboratory durability tests of ceramic mills with different coatings during machining a heat-resistant nickel alloy were carried out. A qualitative assessment of the nickel adherence intensity on the work surfaces of ceramic tools during cutting was performed.

We demonstrate generation of passive Q-switched laser pulses of a linear cavity Er-Yb double-clad fiber laser based on the use of a fiber ball lens coated with a thin film of titanium oxynitride (TiOxNy). The fiber ball lens is inserted within the laser cavity in a reflection configuration, alongside a reflecting mirror. Dual-wavelength and tunable single operations of the laser is obtained with the ball lens acting as an interference filter. At the same time, the ball lens coated with TiOxNy, deposited by DC reactive magnetron sputtering, allows saturable absorption suitable for generation of passive Q-switched laser pulses. Single wavelength laser generation tuned in a range of ~4.5 nm and simultaneous dual wavelength generation with separation of 5.1 nm are obtained at the 1.55 µm wavelength region. Pasive Q-switched pulses with maximum repetition rate of 124 kHz, minimum duration of 3.6 µs and peak power of 360 mW are achieved. The maximum pulse energy estimated is of 1.3 µJ.

The research presents the principles of development and practical implementation (including rational modes) of combined treatment technology for the surface of precision parts with a broad beam of ions and/or fast argon atoms. In a single technological cycle, two process stages are realized: polishing with a beam at an incidence of 80º to the surface of parts made of different material, which enables a precision level of the surface roughness and deposition of protective nanostructured films on the parts immersed in dense plasma produced by magnetron sputtering in a mixture of inert and reactive gases. The developed innovative technology has a wide range of technological applications, but a particularly promising area is the processing of optical parts and elements.

Stranski-Krastanov (SK) Quantum dots (QDs) based lasers and detectors are now used in many fields because of the plentiful advantages they offer, some of which are normal incident absorption and phonon bottleneck. In order to optimize the properties of the devices, growth parameters have to be tuned properly. The effects of growth temperature (GT) and growth rate (GR) variations on the QD devices have been studied here by comparing simulations and experiments. In this study, InAs QDs are grown on GaAs substrates with four different temperatures, from 480°C to 510°C, and with five different GRs, from 0.15 ML/s to 0.025ML/s. To observe the grown heterostructures' structural and optical properties photoluminescence (PL) and PL excitation (PLE) have been performed on the samples. The size, shape, and composition of the QDs ultimately decide the energy levels in the heterostructure. Hence, it determines the optical and electrical properties of the devices. Here we simulated 3-D strain profiles of the QD and compared the results with PL and PLE. The trends in simulated biaxial strain and heavy hole (HH) - light hole (LH) band splitting, observed in the PLE, match pretty well. We observed that the change in GT drastically affects the composition of the dots and the wetting layer, whereas a change in GR only changes the lateral size of the QDs, and do not affect the strain or composition. These studies can be beneficial for p-i-p short-wave infrared (SWIR) detectors since their spectral response is tuned by the HH-LH band splitting.

A glimpse of the efficacy of phase change medium (PCM)-based layered hyperbolic metamaterial (HMM) was emphasized following the analytical investigation of wave propagation through the system. The optical response of HMM was characterized solely by adjusting the materials electrical constants and/or structural parameters, such as the thickness and/or filling fraction. The HMM embedded with graphene and stibnite (Sb2S3) PCM was investigated for angle-invariant, polarization insensitive properties with an in-band rejection over –30 dB, which is tunable in a wavelength span of nearly 50 nm.

Switching and/or sensing characteristics of a specially designed three-layer metamaterial configuration were studied. In particular, the top metasurface is comprised of squared pixels of strontium titanate (SrTiO₃) and graphene mediums, deposited over an InSb nanolayer; the SiO₂ dielectric medium constitutes the bottom substrate. The proposed structure could be artificially controlled and tuned, and therefore, the effects due to altering ambient temperature, graphene chemical potential and magnetostatic bias were studied. The results exhibit high sensitivity resonance transmission in the THz frequency range. The optical switching ON/OFF states of the structure, as represented in the form of transmission spectra, were reported supporting very high (~98%) or almost vanishing transmission.

Birefringence properties have been frequently achieved when subwavelength elements are used on waveguides or devices design and construction. In order to investigate this effect in details we analyze a tilted silicon-on-insulator periodically subwalength waveguides composed of nanowires. The propagation properties are obtained by an efficent frequency domain finite element approach wich takes into accout the periodical boundary conditions The dispersion properties of the waveguides are analyzed in details for several values of duty cycle, nanowires shape and tilting angles. We demonstrate that the resulting birefringence can be tailored by changing the structural parameters of the waveguides. The tilted nanowire based waveguide can work as a birefringent waveguide depending on the propagating polarization, an essential and important condition for a myriad of photonics circuit devices.

In this paper, the Gray Wolf (GWO) algorithm has been used to design and to optimize the geometrical parameters of broadband compact silicon on insulator waveguide crossing structure operating in the wavelength range of 1400–1600 nm. The electromagnetic numerical simulations of the waveguide crossing have been conducted by using an efficient frequency domain finite element (FEM) approach. The objective function is based on the maximization of the transferred power while minimizing the crosstalk. The performance of the optimization algorithm has been assessed by adjusting the number and the initial position of the wolves. Coupling efficiency higher than 96% has been obtained. Moreover, a tolerance error analysis has been carried out for the best crossing configurations to investigate their robustness.

We show a strategy to design polarization-insensitive electro-optical modulators based on the use of single-layer graphene sheets working at the ε-near-zero (ENZ) regime. An external voltage is used to change the optical properties of graphene at will, allowing dynamical tuning of the permittivity between dielectric and metallic behavior. As a proof of concept, we designed an ultra-compact modulator, with a minimum length of 5.22 µm, to produce a 3 dB modulation depth when working at the center of the optical C-band (λ = 1550 nm). The modulation principle is based on the high electromagnetic absorption associated to the ENZ mode of graphene. Our approach can be used for highly integrated, cost-effective and energy-efficient nanophotonic circuits in future optical communication networks.

The development of Hybrid Optical Photonic Organic Devices, using an optically transparent substrate material and organic semiconductor materials, has been widely utilized by the electronic industry when producing new technological products. The Hybrid Optical Photonic Organic Device constructed in this work is electrochromic device with solar cell are the base Poly (3,4-ethylenedioxythiophene), PEDOT:PSS, Poly(3-hexyl thiophene, P3HT, Phenyl-C61-butyric acid methyl ester, PCBM and Polyaniline, PANI, were deposited in Indium Tin Oxide, ITO, and characterized by Electrical Measurements and Scanning Electron Microscopy (SEM). In addition, the thin film obtained by the deposition of PANI, prepared in perchloric acid solution, was identified through PANI-X1. The result obtained by electrical Measurements has demonstrated that the PET/ITO/PEDOT:PSS/P3HT:PCBM Blend/ PANI-X1/ITO/PET layer presents the characteristic curve of standard solar cell after spin-coating and electrodeposition. The Thin film obtained by electrodeposition of PANI-X1 on P3HT/PCBM Blend was prepared in perchloric acid solution. The thermal effects from ultraviolet irradiation under the device’s surface, in the irradiation simulator chamber, demonstrated a 15% reduction in the device’s lifetime. The inclusion of the PANI-X1 layer reduced the effects of degradation these organic photovoltaic panels induced for solar irradiation, a fact that also observed in the irradiation in the simulation chamber. In Scanning Electron Microscopy (SEM) these studies reveal that the surface of PANI-X1 layers is strongly conditioned by the surface morphology of the dielectric.

The rapid advancement of wireless technology has accelerated the market’s demand for flexible and optically transparent antennas. Traditional transparent conductors have drawbacks such as fragility after repeated bending, so they are not appropriate candidates for flexible transparent antenna development. Here, we report a flexible and optically transparent antenna that uses a metallic mesh transparent conductive film embedded in poly (ethylene terephthalate) (PET) substrate. The micro-nano structure of transparent conductive metallic film is made by lithography machine, which has the advantages of patterning. The antenna operates at 3-8 GHz band and shows satisfactory gain and a good radiation pattern. It performs well under bending conditions. The proposed antenna’s optical transparency, mechanical flexible properties, and seamless integration process indicate its promising potential in a variety of transparent antenna applications for future wireless networks.

To fabricate efficient gas sensors with novel engineered nanomaterials, silver nanoparticles (Ag-NPs) were successfully green synthesized by Nd: YAG nanosecond pulsed laser ablation technique using a mixture of diluted silver nitrate solution and citrus limetta juice extract irradiated for different ablation durations at room temperature. Brownish-yellow colloidal Ag-NPs formation was confirmed by UV-Vis spectroscopy with the absorbance peak around 407-419 nm. HR-TEM results confirmed well mono-dispersed spherical shape morphology for Ag-NPs with particle size around 8 nm for near to 80 min of ablation time. Notably, the engineered nanostructured Ag-NPs were used freshly in room temperature fiber optic gas sensing. The sensor exhibited an outstanding linear response for ammonia gas (0-500 ppm). The sensitivity was about 128.7 Counts/kPa for ammonia gas at RT. The dynamic response of the sensor was recorded to be 15.5 s and 3.5 s. In summary, laser-ablated green synthesized Ag-NPs showed excellent efficiency in detecting ammonia gas at room temperature.