Papers by Keyword: Nanophotonics

Abstract: Smart packaging becomes more popular as it increases the safety of food consumption by monitoring a packaged food state and informing the customer about it, for example, by visual reaction of a special label on its surface. Nanomaterials can provide the needed functionality to such labels. Application of ink compositions containing silver nanoparticles on paper materials by screen printing is quite promising. A special ink composition was developed based on Ag nanoparticles that possess changeable photoluminescence properties in contact with compounds that indicate food decay. The possibility of application of this ink onto the surface of paper-based materials via screen printing was studied. The influence of ink layer thickness, characteristics of paper materials (degree of sizing, content of optical brighteners), and content of the fluorescent component in the ink composition on photoluminescence properties of printed labels for smart packaging was investigated. It was determined how to choose proper values of these technological parameters in order to obtain high luminescence intensity and predetermined luminescence color of printed labels using the developed nanophotonic inks. The results of the study allow industrial production of functional labels for smart packaging with nanophotonic elements with the needed optical (photoluminescence) characteristics, as well as for protecting packaging from counterfeiting.

Abstract: Engineering, stability and orientation of semiconducting molecules are necessary to achieve the high efficiency of multifunctional organic-based devices. Several conjugated molecules facilitate the use of external magnetic fields to tailor both their molecular orientation and electronic properties while being processed for bio or opto-electronic applications. In this work, molecular thin films of vanadyl phthalocynine (VOPc) layers forming conducting channels in organic field-effect transistors were investigated. Three systems based on 100 nm thick VOPc thin film were grown, one in absence of magnetic field, while the other two with parallel and perpendicular to the substrate plane, respectively. Devices were ex-situ investigated by electrical characterization and confocal scanning Raman spectroscopy (SRS). All molecular layers growth on Au electrodes presented enhancement of the Raman signal.

Abstract: This presentation provides a panoramic overview of the recent progress in nanoglass plasmonics, challenges, excitement, applied interests and the future promises. A glimpse of our gamut research activities with some significant results is highlighted and facilely analyzed. The term 'nanoglass' refers to the science and technology dealing with the manipulation of the physical properties of rare earth doped inorganic glasses by embedding metallic nanoparticles (NPs) or nanoclusters. On the other hand, the word 'plasmonics' refer to the coherent coupling of photons to free electron oscillations (called plasmon) at the interface between a conductor and a dielectric. Nanoglass plasmonis being an emerging concept in advanced optical material of nanophotonics has given photonics the ability to exploit the optical response at nanoscale and opened up a new avenue in metal-based glass optics. There is a vast array of nanoglass plasmonic concepts yet to be explored, with applications spanning solar cells, (bio) sensing, communications, lasers, solid-state lighting, waveguides, imaging, optical data transfer, display and even bio-medicine. Localized surface plasmon resonance (LSPR) can enhance the optical response of nanoglass by orders of magnitude as observed. The luminescence enhancement and surface enhanced Raman scattering (SERS) are new paradigm of research. A thumbnail sketch of the fundamental aspects of SPR, LSPR, SERS and photonic applications of various rare earth doped/co-doped binary glasses containing metallic NPs are presented. The recent development in nanoglass in the context of Malaysia at the outset of international scenario is projected.

Abstract: In this paper we present the basic theory of nonlinear photonic crystal fibers (PCFs) with a focus on theoretical aspects of generating squeezed light using Kerr effect. The FDTD method is employed to study the guided modes of em field propagation in PCF. The degree of squeezing is determined using correlations function corresponding to the fields of light. It is shown that noise in a squeezed light is reduced to about 24% below the minimum noise observed in coherent light.

Abstract: In this paper, an investigation of optimized vertical and non-vertical nano-slot silicon waveguides with different cover media (cladding) is presented. The mode properties and light confining effects for both of these slot waveguides geometry are investigated at operating wavelength of 1550nm. Light propagation of waveguide modal profiles for electric field and intensity of such slot waveguides are also presented.

Abstract: Contact lenses are a common optical aid to provide help with refractive anomalies of the human eye. Construction of contact lenses is a complex engineering task as it requires knowledge of optics, materials science, production and characterization methods for product quality. Besides correcting refractive anomalies, by using contact lenses it is possible to change the characteristics of light through the manipulation of material structure properties. Nanomaterials, such as fullerene C₆₀, are candidates for the medium that interacts with light, thus changing its properties. During material syntheses for contact lenses, fullerenes are added to the base material and optical characteristics of the new nanophotonic material are compared with the base material. The engineering, manufacture and characterization of both a commercial and a new nanophotonic contact lens is presented in this paper. The interaction of water with both base and nanophotonic contact lens materials is described. Using experimental techniques, the phenomena of an exclusion zone (EZ) is also identified.

Abstract: 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.

Abstract: The impact of developing nanophotonic components have proven to be a promising research on the future optical integrated circuit complementing the current scaling of semiconductors for faster board-board, chip-chip interconnect speeds. Essentially photonic crystals (PhC) symbolize an emerging class of periodic nanomaterials that offers flexibilities in achieving novel devices. Based on the investigations of the high-Q resonance mode energy distributions, we optimized the nano­scale tip for optimal perturbative effect with low loss resonance control in the optical near field regime. In this study to achieve larger spectral resonance, we proposed using a novel doubly nano­scale perturbative tip to achieve optimal accurate photonic crystal resonance control. Such method may be driven by a nano-electromechanical (NEMS) system that may be fabricated with monolithic approaches.

Abstract: An novel optical nano biosensor based on gold capped nano-particles for detecting binding events between ligands and receptor molecules as well as interactions among proteins without use of labels has been presented in this paper. The optical properties of nano-sized gold particles exhibiting pronounced adsorption in the visible region which called as localized surface plasmon resonance (LSPR) have been exploited, whose peak wavelengths depended exquisitely on the refractive index of the surrounding. In comparison with surface plasmon resonance (SPR) technology, the optical nano biosensor possessed high sensitivity, surprisingly low “bulk effect”, ease of preparation, and low-cost polymer based fabrication, which opened a promising bioanalytical application in practice.

Abstract: In this paper, some virtuallab experiments have been done, in which the we get extraordinary transmission phenomenon by adding dielectric coating in the subwavelength periodic metallic slits. It is proved that dielectric coatings on the metal films can excite a surface wave which is transmitted in the metal slits by dielectric waveguides, and the symmetric wrapped dielectric cladding around the metal gains almost 10 times as great transmission as two surfaces cladding does. The paper explores a preliminary physics mechanism of this extraordinary transmission, which gets some valuable results in the application fields.