Improvement of single-mode gain margin in gain-coupled DFB lasers

Author

Chen, Jianyao ; Champagne, Alain ; Maciejko, Romas ; Makino, Toshihiko

Author_Institution

Optoelectron. Lab., Ecole Polytech., Montreal, Que., Canada

Volume

33

Issue

1

fYear

1997

fDate

1/1/1997 12:00:00 AM

Firstpage

33

Lastpage

40

Abstract

Using the Bloch-wave analysis, this paper investigates the effect of the gain grating on the single-mode condition in DFB lasers. Various factors affecting the threshold gain of gain-coupled DFB lasers are analyzed in some detail. It is shown for the first time that unequal section lengths in the gain grating can have a significant effect on the single-mode gain margin of gain-coupled DFB lasers, especially when the linewidth enhancement factor α_M is large, because the long and shortwavelength Bloch waves are in phase and in antiphase with the index grating of DFB lasers, respectively

Keywords

diffraction gratings; distributed feedback lasers; laser modes; laser theory; semiconductor device models; semiconductor lasers; spectral line breadth; Bloch-wave analysis; antiphase; gain grating; gain-coupled DFB lasers; index grating; linewidth enhancement factor; longwavelength Bloch waves; shortwavelength Bloch waves; single-mode condition; single-mode gain margin; threshold gain; unequal section lengths; Coatings; Distributed feedback devices; Fiber lasers; Gratings; Laser feedback; Laser modes; Optical coupling; Optical feedback; Periodic structures; Semiconductor lasers;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/3.554873

Filename

554873