Open AccessEffect of perfectly matched layer reflection coefficient on modal analysis of leaky waveguide modes
Author(s) -
Chih-Hsien Lai,
Hung-Chun Chang
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.19.000562
Subject(s) - reflection coefficient , optics , waveguide , perfectly matched layer , refractive index , reflection (computer programming) , propagation constant , modal , attenuation coefficient , materials science , slab , transmission coefficient , terahertz radiation , physics , finite difference time domain method , transmission (telecommunications) , telecommunications , geophysics , computer science , polymer chemistry , programming language
The reflection coefficient is one important parameter of the perfectly matched layer (PML). Here we investigate its effect on the modal analysis of leaky waveguide modes by examining three different leaky waveguide structures, i.e., the holey fiber, the air-core terahertz pipe waveguide, and the gain-guided and index-antiguided slab waveguide. Numerical results reveal that the typical values 10(-8) ~10(-12) are inadequate for obtaining the imaginary part of the complex propagation constant, and the suggested reflection coefficient would be much smaller, for example, 10(-50) or 10(-100). With such a small coefficient, both the computational window size and the PML thickness can be significantly reduced without loss of stability. Moreover, in some cases, the modal field profiles can only be accurately obtained with such a small coefficient.