Αποτελέσματα Αναζήτησης
In electromagnetics, an evanescent field, or evanescent wave, is an oscillating electric and/or magnetic field that does not propagate as an electromagnetic wave but whose energy is spatially concentrated in the vicinity of the source (oscillating charges and currents).
An evanescent wave is a type of wave that propagates along a specific direction, decays in a particular half-space, and exhibits elliptical polarization with a cycloidal trajectory. AI generated definition based on: Physics Reports, 2015
When total internal reflection occurs, the transmitted field is an evanescent wave; i.e., a surface wave which conveys no power and whose magnitude decays exponentially with increasing distance into Region 2.
Evanescent waves are associated with imaginary wave vector components. Total internal reflection occurs when the magnitude of the wave vector in air is smaller than the required wave vector component along the surface.
An evanescent wave is defined as a small portion of light that extends out of an optical fiber or waveguide due to total internal reflection. This wave penetrates the cladding material and its intensity diminishes exponentially with increasing distance from the interface.
Evanescent Wave. An electromagnetic wave observed in total internal reflection, undersized waveguides, and in periodic dielectric heterostructures. While wave solutions have real wavenumbers k, k for an evanescent mode is purely imaginary.
The book begins with a brief review of the basic concepts of electromagnetism, then introduces evanescent waves through reflection and refraction, and shows how they appear in diffraction problems, before discussing the role that they play in optical waveguides and sensors.
