Unified Approach for Coupling to Cladding and Radiation Modes in Fiber Bragg and Long-Period Gratings

Author

Lu, Yu-Chun ; Yang, Li ; Huang, Wei-Ping ; Jian, Shui-sheng

Author_Institution

Electr. & Comput. Eng. Dept., Mc-Master Univ., Hamilton, ON

Volume

27

Issue

11

fYear

2009

fDate

6/1/2009 12:00:00 AM

Firstpage

1461

Lastpage

1468

Abstract

Couplings of core mode to guided cladding and unguided radiation modes in fiber Bragg and long-period gratings are investigated by a unified approach based on complex mode matching method (CMMM). With the combination of the perfectly matched layer (PML) and the perfectly reflecting boundary (PRB), the continuous radiation modes can be well represented by a set of discrete complex modes so that simulation of coupling to radiation modes is greatly simplified and may be treated in the same fashion as guided modes. Numerical results of fiber Bragg and long-period gratings with refractive index of the outer cladding lower, equal, and higher than that of the inner cladding indicate that the unified approach is highly effective in the simulation of couplings to cladding and radiation modes.

Keywords

Bragg gratings; mode matching; optical fibres; refractive index; FBG; complex mode matching method; fiber Bragg grating; fiber cladding; long-period grating; perfectly matched layer; perfectly reflecting boundary; unguided radiation mode; unified approach; Cladding mode; complex mode; complex mode matching method (CMMM); fiber Bragg gratings (FBGs); long-period fiber gratings (LPFGs); mode coupling; perfectly matched layer (PML); radiation mode;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/JLT.2009.2012725

Filename

4840395