Open AccessConcentrating evanescent waves: Systematic analyses of properties of the needle beam in three-medium dielectric cylindrical waveguide
Author(s) -
Fangli Qin,
Yang Zhao
Publication year - 2011
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.018795
Subject(s) - optics , materials science , beam (structure) , refractive index , waveguide , dielectric , core (optical fiber) , power (physics) , beam diameter , optoelectronics , physics , laser beams , laser , quantum mechanics
Needle beam is a guided beam with nanoscale beam size and significant power propagating in core area of a three-layer dielectric waveguide. Systematical numerical analyses of properties of the needle beam are presented. Properties of the fundamental mode of the needle beam, including field distribution, power distribution, and power concentration, are calculated for different waveguide parameters. It is shown that there is an optimum value of normalized frequency for maximum power concentration. Concentrated power is higher if the refractive index difference between the core and the middle layer is higher.