In metamaterials, metallic nanowires are used for creating artificial materials to functionalize them for various nanophotonics applications. Strong polarization-dependent response coupled with complex dielectric function at optical frequencies gives additional degrees of freedom to achieve scattering, absorption, and other benefits that go much beyond what is possible with conventional materials. In this paper, we propose an extended cylindrical wave impedance approach at optical frequencies to model the internal and external impedance of the metallic nanowire. Equivalent analytical expression for the scattering, extinction, and absorption cross-sectional area efficiencies are derived in terms of impedances. The motivation is to develop an all-mode solution ( ${\mathbf{TM}}_n$ and ${\mathbf{TE}}_n$ modes), by bringing the complex problem of plasmonic nanowire to linear system theory, where established methods can be applied to enable new applications. The equivalence of the impedance solution is compared with electromagnetic field solution and numerical full-wave field simulations. The proposed solution is accurate and may contribute to the rapid and efficient future designs for the metallic nanowire-based nanophotonic metamaterials.

Recent research in plasmonics demonstrated merging different materials and shapes to form complex geometries with improved optical response. One of the most extensively used nanostructure is the coated nanosphere (nanoshell), which finds its application in diverse fields of medical, science and engineering. In this paper, we propose a compact impedance model of metallic core nanoshell. The model is based on time-varying approach by solving full dipole equation for the metallic core and impedance of the dielectric shell is derived using near-field components of the dipole field. The expressions for the absorption and scattering cross-sectional areas, and their behavior with change in the dielectric function are derived for the first time for nanoshell using voltages, currents and circuit elements, with their equivalence compared with exact solution. Additionally, the effects of changes in nanoshell parameters (dielectric constants, thickness of shell layer and radii of core) on the resonance frequency predicted by the proposed impedance model are analyzed. The simplified impedance model is based on parallel resonance circuit and contributes to the better understanding the behavior of nanoshell and facilitate cost-effectiveness solution for the next generation nanoshell based metamaterials.

In this paper, we have given the design and development of a new wearable device that assists visually impaired individuals to travel independently and confidently. The newly proposed device is based on range-based sensors and would work effectively in both indoor and outdoor conditions. It is constructed in the form of two separate modules; one module is designed such that it can be attached to the waist belt of the user, and the other module is designed to wear it on ankle of the user. Both the modules communicate with each other using wireless communication and can cover the full front environment of the user. The information about the front environment is transmitted to the user, via headphone, by sending a set of voice instructions, stored in a memory card added in the belt module. In order to use the device in crowd mode, appropriate networking techniques were also implemented in the prototype such that the interference of two or more devices in the close vicinity can be avoided. In the end, effectiveness of the device is analyzed and proved by conducting experiments and obtaining statistical results.