Effects of structural parameters on the external optical feedback sensitivity in DFB semiconductor lasers

Author

Alam, Mohammad F. ; Karim, Mohammad A. ; Islam, Saiful

Author_Institution

Center for Electro-Opt., Dayton Univ., OH, USA

Volume

33

Issue

3

fYear

1997

fDate

3/1/1997 12:00:00 AM

Firstpage

424

Lastpage

433

Abstract

External optical feedback sensitivity in distributed feedback (DFB) semiconductor lasers is analyzed with special attention to phase-shifted and complex-coupled lasers. The effects of various structural parameters such as coupling strength, facet reflectivity, and corrugation phase angle on external optical feedback sensitivity are studied. The λ/4 phase-shifted index-coupled DFB laser exhibits low external optical feedback sensitivity for large index-coupling coefficient and high facet reflectivity. Pure gain-coupled DFB lasers perform better than the phase-shiftless uniform index-coupled DFB lasers but worse than λ/4 phase-shifted index-coupled lasers with high coupling strengths. External optical feedback sensitivity of complex-coupled lasers depends significantly on the index-to-gain coupling ratio, the phase between the index and gain gratings, and the total coupling

Keywords

diffraction gratings; distributed feedback lasers; laser feedback; laser theory; optical couplers; optical transmitters; phase shifters; reflectivity; refractive index; semiconductor device models; semiconductor lasers; sensitivity; λ/4 phase-shifted index-coupled lasers; DFB semiconductor lasers; complex-coupled lasers; corrugation phase angle; coupling strength; external optical feedback sensitivity; facet reflectivity; gain gratings; high coupling strengths; high facet reflectivity; high facet reflectivity. Pure gain-coupled DFB lasers perform better than the phase-shiftless uniform; index gratings; index-to-gain coupling ratio; large index-coupling coefficient; low external optical feedback sensitivity; phase-shifted; phase-shifted index-coupled DFB laser; phase-shiftless uniform index-coupled DFB lasers; pure gain-coupled DFB lasers; structural parameters; Distributed feedback devices; Laser feedback; Laser modes; Laser noise; Laser stability; Laser theory; Laser transitions; Optical coupling; Optical feedback; Semiconductor lasers;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/3.556012

Filename

556012