Nonlinear mechanisms of filamentation in broad-area semiconductor lasers

Author

Marciante, John R. ; Agrawal, Govind P.

Author_Institution

Inst. of Opt., Rochester Univ., NY, USA

Volume

32

Issue

4

fYear

1996

fDate

4/1/1996 12:00:00 AM

Firstpage

590

Lastpage

596

Abstract

There are three nonlinear mechanisms that can lead to filamentation in broad-area semiconductor lasers: gain-saturation-induced changes in the refractive index through the linewidth-enhancement factor, self-focusing due to heat-induced index changes, and self-defocusing through intensity-dependent index changes in the cladding layer. We present a theoretical model to analyze these mechanisms and their relative roles in destabilizing the laser output. We find that there exists a critical value for the linewidth-enhancement factor below which broad area lasers are stable for wide stripe widths (as wide as 250 μm) and high pumping levels (as high as 20 times threshold). We also find that broad-area lasers are less susceptible to filamentation through self-defocusing and show how an intensity-dependent index in the cladding layer may be used to suppress filamentation caused by the linewidth-enhancement factor

Keywords

claddings; laser stability; laser theory; nonlinear optics; optical pumping; optical self-focusing; refractive index; semiconductor lasers; spectral line breadth; 250 mum; broad-area semiconductor lasers; cladding layer; filamentation; gain-saturation-induced changes; heat-induced index changes; high pumping levels; intensity-dependent index; intensity-dependent index changes; laser output destabilisation; linewidth-enhancement factor; nonlinear mechanisms; refractive index; self-defocusing; self-focusing; theoretical model; threshold; wide stripe widths; Laser modes; Laser theory; Laser transitions; Nonlinear optics; Optical pumping; Optical refraction; Optical saturation; Pump lasers; Refractive index; Semiconductor lasers;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/3.488831

Filename

488831