1 Department of Photonics Engineering, Technical University of Denmark2 Nanophotonics Theory and Signal Processing, Department of Photonics Engineering, Technical University of Denmark3 Department of Micro- and Nanotechnology, Technical University of Denmark4 Risø National Laboratory for Sustainable Energy, Technical University of Denmark
The gain spectra of a submonolayer (SML) InGaAs/GaAs quantum dot (QD) laser working at 30°C were measured using the Hakki–Paoli method. It is found that the maximum modal gain of QD ground states is as high as 44 cm–1 and no gain saturation occurs below the threshold at the lasing wavelength of 964.1 nm. When the injection current is about 0.98 times the threshold, the gain spectrum becomes symmetric with respect to the lasing wavelength, and zero-linewidth enhancement factor is observed. These properties are attributed to the high density and the high uniformity of SML QDs in our laser diode.
Applied Physics Letters, 2004, Vol 85, Issue 15, p. 3259-3261
LAYER; REFRACTIVE-INDEX; POWER; DIODE-LASER; DIFFERENTIAL GAIN; GROWTH; WELL LASERS; EFFICIENCY