Title :
Linewidth enhancement factor in InGaAs quantum-dot amplifiers
Author :
Schneider, Stephan ; Borri, Paola ; Langbein, Wolfgang ; Woggon, Ulrike ; Sellin, Roman L. ; Ouyang, D. ; Bimberg, Dieter
Author_Institution :
Univ. Dortmund, Germany
Abstract :
We report systematic measurements of the linewidth enhancement factor (LEF) in an electrically pumped InGaAs quantum-dot (QD) amplifier in the temperature range from 50 K to room temperature. At injection currents below transparency, the value of the linewidth enhancement factor of the ground-state interband (excitonic) transition is between 0.4 and 1, and increases with increasing carrier density. Additionally, we investigate the spectral dependence of the LEF by tuning the wavelength of our optical probe from below resonance with the ground state of the QDs up to resonance with the first optically active excited-state transition. We find a decrease of the LEF with increasing photon energy at all investigated temperatures.
Keywords :
III-V semiconductors; carrier density; excited states; gallium arsenide; ground states; indium compounds; laser tuning; quantum dot lasers; semiconductor device measurement; semiconductor optical amplifiers; spectral line breadth; transparency; 50 to 293 K; InGaAs; InGaAs quantum-dot amplifiers; carrier density; electrical pumping; excited state transition; ground-state interband transition; injection currents; linewidth enhancement factor; quantum dots; room temperature; semiconductor devices; semiconductor lasers; spectroscopy; transparency; wavelength tuning; Charge carrier density; Electric variables measurement; Indium gallium arsenide; Optical amplifiers; Optical pumping; Optical tuning; Probes; Quantum dots; Resonance; Temperature distribution; Amplifiers; QDs; quantum dots; semiconductor devices; semiconductor lasers; spectroscopy;
Journal_Title :
Quantum Electronics, IEEE Journal of
DOI :
10.1109/JQE.2004.834779
