The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.

http://ieeexplore.ieee.org/iel5/6354/16969/00781867.pdf

Photonic crystals

Metamaterials and transformation optics play substantial roles in various branches of optical science and engineering by providing schemes to tailor electromagnetic fields into desired spatial patterns. We report a theoretical study showing that by designing and manipulating spatially inhomogeneous, nonuniform conductivity patterns across a flake of graphene, one can have this material as a one-atom-thick platform for infrared metamaterials and transformation optical devices. Varying the graphene chemical potential by using static electric field yields a way to tune the graphene conductivity in the terahertz and infrared frequencies. Such degree of freedom provides the prospect of having different "patches" with different conductivities on a single flake of graphene. Numerous photonic functions and metamaterial concepts can be expected to follow from such a platform.

http://science.sciencemag.org/content/suppl/2011/06/08/332.6035.1291.DC1/Vakil-SOM.pdf

Transformation Optics Using Graphene

International Technology Roadmap for Semiconductors 2003の要求清浄度について － シリコンウエハ表面と雰囲気環境に要求される清浄度, 分析方法の現状について －

Introduction to Nanotechnology

http://ieeexplore.ieee.org/iel5/5/31325/01456922.pdf

An introduction to optical waveguides

The quality of agricultural products is of high importance in terms of consumer interest, determining market acceptance, and thus, directly affects storage and post-harvest processing operations. Quality measurement of fruits, vegetables and food products is at the center of attention by the food industry. Non-destructive measurements of quality parameters have been conducted on many agricultural products and have proved to be rapid and accurate in estimating the quality factors involved. While, non-destructive methods are very useful for quality testing, the recent interest by consumers, researchers, and the food industry in the application of new portable and/or handheld non-destructive devices for quality assessment of agricultural products has added a new dimension to the issue. Because these devices are small-sized, low-cost, low-weight, and easy to use, they can be utilized by farmers, quality inspectors, and even consumers. Thus, researchers have focused on developing portable non-destructive devices for a variety of food items. This review, examines the latest reports on the design and development of dedicated non-destructive portable and/or handheld devices for quality monitoring of agricultural products.

Dedicated non-destructive devices for food quality measurement: A review

In this paper, a coupled optical-electrical modeling method is applied to simulate perovskite solar cells (PSCs) to find ways to improve light absorption by the active layer and ensure that the generated carriers are collected effectively. Initially, a planar structure of the PSC is investigated and its optical losses are determined. To reduce the losses and enhance collection efficiency, a convex light-trapping configuration of PSC is used and the impacts of these nanostructures on all parts of the cell are investigated. In this convex nanostructured PSC, the power conversion efficiency (PCE) is found to be increased when the thickness of the absorbing layer remained unchanged. Then, a plasmonic reflector is applied to trap light inside the perovskite. In this structure, by scattering light through the surface plasmon resonance (SPR) effect of the Au back-contact, the electromagnetic field is found to concentrate in the active layer. This results in increased perovskite absorption and, consequently, a high current density of the cell. In the final structure, which is the integration of these two structures, optical losses are found to be greatly diminished and the short-circuit current density (Jsc) is increased from 18.63 mA/cm2 for the planar structure to 23.5 mA/cm2 for the proposed structure. Due to the increased Jsc and open-circuit voltage (Voc) caused by the improved carrier collection, the PCE increases from 14.62 to 19.54%.

/pdf/high-performance-perovskite-solar-cell-using-photonic-3gzy603rdu.pdf

High-performance perovskite solar cell using photonic-plasmonic nanostructure.

A new technique for analysing the time-domain response of carbon nanotube (CNT) interconnects, based on transmission line modelling, that takes the effects of both contact and fundamental (quantum) resistances into account is introduced. A new sixth-order linear parametric expression for the transfer function of these lines has been presented for the first time. For verification purposes, the step response of a driver-CNT bundle-load configuration for a 32 nm technology node, using the new technique and HSPICE simulation have been compared, with which the obtained results show an excellent match. Also the effect of contact resistance on the step response, especially the propagation delay, has been studied. The obtained results show that for the length of a CNT bundle equal to 50 mum with the diameter of each individual CNT 1 nm, the propagation delay changes from 0.138 to 5.58 ns for the contact resistance values from 1 to 50 k Omega, i.e. a variation range of 39.43 times the minimum value. The related delay variations for the length values 200 mum, 500 mum and 1000 mum, are 31.37, 22.61 and 15.42 times the minimum value, respectively.

Davood Fathi

Papers

Dedicated non-destructive devices for food quality measurement: A review

High-performance perovskite solar cell using photonic-plasmonic nanostructure.

Accurate analysis of carbon nanotube interconnects using transmission line model

Rapid measurement of apple quality parameters using wavelet de-noising transform with Vis/NIR analysis.

Design and simulation of perovskite solar cells based on graphene and TiO2/graphene nanocomposite as electron transport layer