Reduction of effective linewidth enhancement factor alpha /sub eff/ of DFB lasers with complex coupling coefficients

Author

Kudo, Koji ; Shim, Jong In ; Komori, Kazuhiro ; Arai, Shigehisa

Author_Institution

Dept. of Phys. Electron., Tokyo Inst. of Technol., Japan

Volume

4

Issue

6

fYear

1992

fDate

6/1/1992 12:00:00 AM

Firstpage

531

Lastpage

534

Abstract

The effective linewidth enhancement factor alpha /sub eff/ of DFB lasers which have both gain and index coupling coefficients is theoretically analyzed. The unique reduction mechanism of alpha /sub eff/ due to the optical negative feedback of modal phase and modal gain in gain coupled DFB lasers was found for the first time. The numerical result showed that alpha /sub eff/ can be reduced to almost one half of the material defined linewidth enhancement factor alpha when there exists an index coupling coefficient comparable to the gain coupling coefficient.<>

Keywords

distributed feedback lasers; feedback; laser theory; optical constants; refractive index; semiconductor junction lasers; spectral line breadth; complex coupling coefficients; effective linewidth enhancement factor; gain coupled DFB lasers; gain coupling coefficients; index coupling coefficients; modal gain; modal phase; optical negative feedback; reduction mechanism; Laser feedback; Laser modes; Laser theory; Negative feedback; Optical coupling; Optical feedback; Optical materials; Optical refraction; Reflectivity; Refractive index;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/68.141957

Filename

141957