Relation of the angular momentum of surface modes to the position of their power-flow center

We show that the value of the total angular momentum (AM) carried by a surface mode can be interpreted as representing the transverse position of the center or balance point of the power flow through the mode. Especially in the lossless cases, the value of the Abraham AM per unit power (multiplied by the square of the speed of light in vacuum) is exactly the same as the transverse position of this power-flow center. However, the Minkowski counterpart becomes proportional to that position with a coefficient in the form of 1 + η, where η is determined mainly by the constitutive parameters of media

A non-reflecting metamaterial slab under the finite-embedded coordinate transformation

From the explicit solutions of Maxwell's equations under the coordinate transformation, the conditions for non-reflecting boundaries for the two-dimensionally propagating light waves, in a finite-embedded coordinate transformation metamaterial slab are derived in cases of extended two-dimensional. By exploring several examples, including some reported in the literatures and some novel developed in this study, we show that our approach can be used to efficiently determine the condition in which a finite-embedded coordinate transformed metamaterial slab is non-reflecting.Comment: 13 page

Effect of finite metallic grating size on Rayleigh anomaly-surface plasmon polariton resonances

Rayleigh anomalies (RAs) and surface plasmon polaritons (SPPs) on subwavelength metallic gratings play pivotal roles in many interesting phenomena such as extraordinary optical transmission. In this work, we present a theoretical analysis of the effect of finite metallic grating size on RA-SPP resonances based on the combination of rigorous coupled wave analysis and finite aperture diffraction. One-dimensional arrays of gold subwavelength gratings with different device sizes were fabricated and the optical transmission spectra were measured. As the grating size shrinks, the broadening of the RA-SPP resonances is predicted by the theoretical model. For the first order RA-SPP resonances, the results from this model are in good agreement with the spectra measured from the fabricated plasmonic gratings

Slow-light effect via Rayleigh anomaly and the effect of finite gratings

In this Letter, we investigate the slow-light effect of subwavelength diffraction gratings via the Rayleigh anomaly using a fully analytical approach without needing to consider specific grating structures. Our results show that the local group velocity of the transmitted light can be significantly reduced due to the optical vortex, which can inspire a new mechanism to enhance light–matter interactions for optical sensing and photodetection. However, the slow-light effect will diminish as the transmitted light propagates farther from the grating surface, and the slowdown factor decreases as the grating size shrinks.This paper was published in Optics Letters and is made available as an author's peer-reviewed final manuscript, as accepted by the publisher. The paper can be found at the following URL on the OSA website: https://www.osapublishing.org/ol/abstract.cfm?uri=ol-40-22-5339. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.Keywords: Electromagnetic optics, Subwavelength structures, Diffraction gratingsKeywords: Electromagnetic optics, Subwavelength structures, Diffraction grating

The Korean urban rural elderly cohort study: study design and protocol

BACKGROUND: Korea is one of the fastest aging countries and is expected to become a super-aged society within 12 years. The Korean Urban Rural Elderly (KURE) study was developed to evaluate the epidemiological characteristics and establish the prevention and management of major disorders of the elderly in Korea. METHODS/DESIGN: The KURE study is a community-based prospective cohort study on health, aging, and common geriatric disorders of Korean elderly persons aged at least 65 years. To construct a cohort reflecting both urban and rural areas, we selected 2 representative communities in the country. To establish multidisciplinary approaches to geriatric health, this study was performed by researchers in the divisions of geriatrics, preventive medicine, endocrinology, and sociology. The baseline examinations began in 2012; the study will follow more than 4,000 elderly Koreans over 10 years. The first and second follow-up health examinations will be performed every 4 years. Every 2 years after each health examination, inter-assessment interview will be conducted to improve participant retention. DISCUSSION: The KURE study will provide longitudinal epidemiologic data on health, aging, and common geriatric disorders of the elderly in Korea. This is a comprehensive, multidisciplinary study of the elderly with respect to biological, physical, socio-economic, and environmental factors. The results of this study will contribute to improve public health and welfare policies for the aging society in Korea

An efficient numerical scheme for the discrete Wigner transport equation via the momentum domain narrowing

We propose a numerical scheme that narrows down the momentum domain of the Wigner function to enhance numerical efficiency. It enables us to decrease the number of mesh points while maintaining the same mesh spacing in the momentum coordinate. The proposed scheme thus not only requires less memory but can significantly reduce the computation time. To minimize resultant loss of numerical accuracy, we also propose the partial local potential averaging method

Guiding principle of light waves through metamaterial layers

This paper has been withdrawn by the author.Comment: This paper has been withdraw