Abstract

So far, long wavelength Stranski-Krastanow (SK) quantum dots (QDs) have been failed to provide enough differential gain and temperature stability, required for high speed VCSEL - the fastest modulation bandwidth of a SK QD-VCSEL is only 3 GHz [1], In contrast, InGaAs quantum dots, grown at low temperatures of ~ 400 °C (LTQDs), demonstrate the possibility to reach simultaneously long wavelengths and a high QD density with an exciton-like recombination mechanism. LTQDs allow a high modal gain, avoid temperature depletion and gain saturation effects. Thus they are suitable for high-speed vertical-cavity surface-emitting lasers (VCSELs).

© 2007 IEEE