Analysing distributed feedback waveguides

Author

Gong, J. ; Zheng, X. ; Liao, Y. ; Jin, W. ; Demokan, M.S.

Author_Institution

Dept. of Electron. Eng., Tsinghua Univ., Beijing, China

Volume

146

Issue

6

fYear

1999

fDate

12/1/1999 12:00:00 AM

Firstpage

253

Lastpage

258

Abstract

A method for analysing distributed feedback waveguides with arbitrary refractive index profiles is reported. The method considers a waveguide as a number of segments within which the reflection is weak, and thus the relevant transmission loss and multiple reflections can be neglected. By introducing a concept of reflective density formulas are derived for calculating the reflection and transmission coefficients and therefore the transfer matrix of an individual waveguide segment. The global reflection and transmission characteristics of the waveguide are then obtained by multiplying transfer matrices of all the waveguide segments together. The proposed method shows better accuracy than the coupled-mode method and requires less computation time than the effective-index method. The limitation of the coupled-mode method is shown both numerically and analytically for the first time and it is demonstrated that the coupled-mode method is only valid for analysing long Bragg gratings with particular initial phases

Keywords

Bragg gratings; light reflection; light transmission; matrix algebra; optical multilayers; optical waveguide theory; optical waveguides; arbitrary refractive index profiles; coupled-mode method; distributed feedback waveguides; effective-index method; individual waveguide segment; initial phases; long Bragg gratings; multiple reflections; reflection; reflection coefficients; reflective density formulas; transfer matrices; transfer matrix; transmission coefficients; transmission loss; waveguide segments;

fLanguage

English

Journal_Title

Optoelectronics, IEE Proceedings -

Publisher

iet

ISSN

1350-2433

Type

jour

DOI

10.1049/ip-opt:19990795

Filename

827273