Influence of DX centers on the performance of unipolar semiconductor lasers based on GaAs-Al/sub x/Ga/sub 1-x/As

Author

Sirtori, Carlo ; Barbieri, Stefano ; Kruck, Peter ; Piazza, Vincenzo ; Beck, Mattias ; Faist, Jéerôme ; Oesterle, Ursula ; Collot, Philippe ; Nagle, Julien

Author_Institution

Lab. Central de Recherches, Thomson-CSF, Orsay, France

Volume

11

Issue

9

fYear

1999

Firstpage

1090

Lastpage

1092

Abstract

Optical and electrical characteristics of quantum cascade lasers, made in the GaAs-Al/sub x/Ga/sub 1-x/As material system, show persistent changes at low temperatures, when devices are illuminated with an external white light. The magnitude of the effect is a function of the exposure time and finally saturates. The induced variation on the threshold current density of the lasers is more than 30%. This effect is related to the presence of deep donors (DX centers) in the high aluminum content AlGaAs cladding layers, which under illumination release electrons, thus increasing waveguide losses. By analyzing the light induced variations of the optical characteristics we were able to deduce the waveguide losses of our devices.

Keywords

III-V semiconductors; aluminium compounds; deep levels; electron traps; gallium arsenide; laser beams; optical losses; semiconductor lasers; waveguide lasers; AlGaAs cladding layers; DX centers; GaAs-Al/sub x/Ga/sub 1-x/As laser; GaAs-AlGaAs; deep donors; electrical characteristics; electron release; exposure time; external white light; illumination; light induced variations; optical characteristics; quantum cascade lasers; threshold current density; unipolar semiconductor lasers; waveguide losses; Electric variables; Optical devices; Optical losses; Optical materials; Optical saturation; Optical waveguides; Quantum cascade lasers; Temperature; Threshold current; Waveguide lasers;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/68.784160

Filename

784160