Theoretical and computational analysis of second- and third-harmonic generation in periodically patterned graphene and transition-metal dichalcogenide monolayers

Remarkable optical and electrical properties of two-dimensional (2D) materials, such as graphene and transition-metal dichalcogenide (TMDC) monolayers, offer vast technological potential for novel and improved optoelectronic nanodevices, many of which relying on nonlinear optical effects in these 2D materials. This article introduces a highly effective numerical method for efficient and accurate description of linear and nonlinear optical effects in nanostructured 2D materials embedded in periodic photonic structures containing regular three-dimensional (3D) optical materials, such as diffraction gratings and periodic metamaterials. The proposed method builds upon the rigorous coupled-wave analysis and incorporates the nonlinear optical response of 2D materials by means of modified electromagnetic boundary conditions. This allows one to reduce the mathematical framework of the numerical method to an inhomogeneous scattering matrix formalism, which makes it more accurate and efficient than previously used approaches. An overview of linear and nonlinear optical properties of graphene and TMDC monolayers is given and the various features of the corresponding optical spectra are explored numerically and discussed. To illustrate the versatility of our numerical method, we use it to investigate the linear and nonlinear multiresonant optical response of 2D-3D heteromaterials for enhanced and tunable second- and third-harmonic generation. In particular, by employing a structured 2D material optically coupled to a patterned slab waveguide, we study the interplay between geometric resonances associated to guiding modes of periodically patterned slab waveguides and plasmon or exciton resonances of 2D materials.Comment: 28 pages, 21 figure

How local regulations can help meet our housing needs

Gretchen Weismann and Maggie Adams of Northeastern University's Center for Urban and Regional Policy analyze how building codes and zoning regulations affect housing costs and impede the construction of affordable housing. They also profile successful regulatory practices around the country.Housing

Girls in the 'Hood: The Importance of Feeling Safe

Looks at how adolescent girls benefited from moving out of extremely poor, high-crime neighborhoods into lower poverty areas through the Moving to Opportunity program. Focuses on reduced "female fear" as one reason why girls benefited more than boys

Struggling to Stay Out of High-Poverty Neighborhoods: Lessons From the Moving to Opportunity Experiment

Analyzes the later relocation patterns of families who moved out of high-poverty areas in the Moving to Opportunity program, and explores the reasons why many returned to poorer neighborhoods over time while others remained in low-poverty areas

Accurate near-field calculation in the rigorous coupled-wave analysis method

The rigorous coupled-wave analysis (RCWA) is one of the most successful and widely used methods for modeling periodic optical structures. It yields fast convergence of the electromagnetic far-field and has been adapted to model various optical devices and wave configurations. In this article, we investigate the accuracy with which the electromagnetic near-field can be calculated by using RCWA and explain the observed slow convergence and numerical artifacts from which it suffers, namely unphysical oscillations at material boundaries due to the Gibb's phenomenon. In order to alleviate these shortcomings, we also introduce a mathematical formulation for accurate near-field calculation in RCWA, for one- and two-dimensional straight and slanted diffraction gratings. This accurate near-field computational approach is tested and evaluated for several representative test-structures and configurations in order to illustrate the advantages provided by the proposed modified formulation of the RCWA.Comment: 13 pages, 12 figure

Aufsätze über Vererbung und verwandte biologische Fragen

Die vorliegenden Aufsätze erscheinen hier zum ersten Mal in deutscher Sprache als ein Ganzes, nachdem sie in englischer und französischer Sprache schon früher zusammengefasst worden sind. ..

Thatsachen und Auslegungen in Bezug auf Regeneration

Dieser Aufsatz sollte ursprünglich nur einen Bericht über einige in jüngster Zeit veröffentlichte, aber weiteren Kreisen wohl noch nicht bekannte Beobachtungen geben, die mir neues Licht auf den Vorgang der Regeneration zu werfen scheinen. Es erwies sich dann aber doch notwendig, einige allgemeine Ueberlegungen in den bloßen Bericht einzuflechten und zu zeigen, in welcher Weise diese und andere Vermehrungen des Thatsachenbestandes unseres Wissens sich mit den allgemeinen Anschauungen vereinigen lassen, die ich früher schon entwickelt habe, oder auch, was an letzteren geändert werden muß, um sie mit dem heute vorliegenden Thatsachenbestand in Einklang zu setzen

St. Cloud State Teachers College During The War Years: Contributions Made By the St. Cloud State Teachers College during the Period from 1939 to the End of the Korean Conflict

St. Cloud State administrator John Weismann chronicles the activities of St. Cloud State from the start of World War II in 1939 to the end of the Korean War in 1953.https://repository.stcloudstate.edu/archives_univpubs/1038/thumbnail.jp