Ultrafast gain recovery and modulation limitations in self-assembled quantum-dot devices

Author

Berg, Tommy W. ; Bischoff, Svend ; Magnusdottir, Ingibjorg ; Mørk, Jesper

Author_Institution

Res. Center COM, Tech. Univ. Denmark, Lyngby, Denmark

Volume

13

Issue

6

fYear

2001

fDate

6/1/2001 12:00:00 AM

Firstpage

541

Lastpage

543

Abstract

Measurements of ultrafast gain recovery in self-assembled InAs quantum-dot (QD) amplifiers are explained by a comprehensive numerical model. The QD excited state carriers are found to act as a reservoir for the optically active ground state carriers resulting in an ultrafast gain recovery as long as the excited state is well populated. However, when pulses are injected into the device at high-repetition frequencies, the response of a QD amplifier is found to be limited by the wetting-layer dynamics.

Keywords

III-V semiconductors; excited states; ground states; indium compounds; laser beams; laser theory; numerical analysis; optical modulation; quantum well lasers; self-assembly; semiconductor optical amplifiers; semiconductor quantum dots; wetting; InAs; InAs quantum-dot amplifiers; comprehensive numerical model; excited state; excited state carriers; high-repetition frequencies; modulation limitations; optically active ground state carriers; pulse injection; reservoir; self-assembled InAs quantum-dot amplifiers; self-assembled quantum-dot devices; ultrafast gain recovery; wetting-layer dynamics; Gain measurement; Numerical models; Optical amplifiers; Optical modulation; Pulse amplifiers; Quantum dots; Reservoirs; Stationary state; Stimulated emission; Ultrafast optics;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/68.924013

Filename

924013