A three-dimensional model has been developed for the investigation of the coupling of symmetric (TM01) and asymmetric (HEM11) modes in a high-power, high-efficiency traveling-wave amplifier. In the framework of a simplified model it is shown that the coupling between these two modes is determined by a single parameter that depends on the beam characteristics. For a specific set of parameters co...

A single metallic nanodisk is the simplest plasmonic nanostructure, but it robust enough to generate a Fano resonance in forward and backward scattering spectra by increment of height symmetric asymmetric dielectric environment. Thanks phase retardation effect, non-uniform distribution electric field along aluminum (Al) generates out-of-plane higher-order modes, which interfere with dipolar mod...

Asymmetric mode transformation in waveguide is of great significance for on-chip integrated devices with one-way effect, while it challenging to achieve asymmetric nonlinear-mode-conversion (NMC) due the limitations imposed by phase-matching. In this work, we theoretically proposed a new scheme realizing NMC combining frequency-doubling process and periodic PT symmetric modulation an optical wa...

Introduction Abnormal neural impulses in the nervous system may lead to various diseases and disabilities. High frequency alternating currents (HFAC) has been used to block the propagation of such impulses and improve the symptoms or disabilities. The technique is safe, reversible, and relatively selective, and its reliability, the optimum stimulation parameters, and elimination of the onset re...

Animal tissue development relies on precise generation and deployment of specific cell types into tissue sub-structures. Understanding how this process is regulated remains a major challenge of biology. In many tissues, development progresses through a sequence of dividing progenitor cells, each with decreasing potency, that balance their growth and differentiation. Dividing progenitor cells th...

Polarized infrared reflection spectra of Sr(C103)2 single-crystal plates are recorded and analysed for the frequencies of the transversal and longitudinal optical zone-centre phonon modes and other oscillator parameters by Kramers-Kronig analyses and both the classical 3 parameter (dielectric sum-function) and the 4 parameter (factorized form) oscillator-fit methods. The frequencies computed ar...