The angular spectrum method is a rigorous method to synthesize near and far-field electromagnetic beams from planar field distributions. However, this limitation of planar surfaces has restricted its applicability to beams with simple focal planes. We propose a curved boundary integral method (CBIM) to synthesize electromagnetic beams from arbitrary surfaces to address this limitation and expand the method's scope to synthesize beams from and between shaped objects. This study presents a detailed theoretical framework behind the CBIM and validates its effectiveness and accuracy with a comprehensive set of simulations. Additionally, we present mathematical proof to support our proposal. The proposed method satisfies Maxwell's equations and significantly benefits optical systems and inverse beam design. It allows for analyzing electromagnetic forward/backward propagation between optical elements using a single method. It is also valuable for optical force beam design and analysis.
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http://dx.doi.org/10.1364/OE.504786 | DOI Listing |
Nature
January 2025
Department of Physics, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China.
The concept of non-Hermiticity has expanded the understanding of band topology, leading to the emergence of counter-intuitive phenomena. An example is the non-Hermitian skin effect (NHSE), which involves the concentration of eigenstates at the boundary. However, despite the potential insights that can be gained from high-dimensional non-Hermitian quantum systems in areas such as curved space, high-order topological phases and black holes, the realization of this effect in high dimensions remains unexplored.
View Article and Find Full Text PDFPhys Rev E
November 2024
Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Mass transfer to the reactive wall of a curved cylindrical tube is analyzed in the combined entry region where both momentum and concentration boundary layers are developing. The velocity and concentration distributions developing from uniform inlet profiles are obtained using perturbation analysis, accounting for acceleration of the inviscid flow outside the boundary layer arising from channel curvature and flow displacement. The enhancement in the average flux of the reactive species at the tube wall downstream of the inlet is determined and compared to predictions of numerical simulations.
View Article and Find Full Text PDFA number of undescribed species of the bethylid genera Goniozus and Sierola have been discovered in Australia and North America with character states that had previously been thought to be exclusive to one or the other, prompting a re-examination of the generic boundaries. Analysis of a large dataset of cytochrome oxidase I mtDNA sequences and key morphological characters found that Goniozus is well defined by two insertion-deletion events in COI. The traditional morphological characters can also be used to separate the genera, but variation within the regional fauna must be taken into account.
View Article and Find Full Text PDFACS Nano
December 2024
Sorbonne Université, CNRS, Institut des NanoSciences de Paris, 75005 Paris, France.
J Am Chem Soc
December 2024
Technical University of Munich (TUM), Campus Straubing for Biotechnology and Sustainability, Uferstraße 53, Straubing 94315, Germany.
Electrochemical systems with increasing complexity are gaining importance in catalytic energy conversion applications. Due to the interplay between transport phenomena and chemical kinetics, predicting optimization is a challenge, with numerous parameters controlling the overall performance. Zone diagrams provide a way to identify specific kinetic regimes and track how variations in the governing parameters translate the system between either adverse or optimal kinetic states.
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