Effects of Dot-height Uniformity on the Performance of 1.3 µm InAs Quantum Dot Lasers

We have systematically investigated the growth parameters of InAs quantum dots (QDs) so as to preserve the uniformity of dot height for 1.3 µm OD laser diodes. It is found that the uniformity of dot height plays an important role in contributing to the enhancement of radiative efficiency and the narrowed linewidth of emission spectra. As-cleaved ridge laser diode prepared using the optimized dot-height uniformity exhibit low threshold current density as low as 250 A/cm2 and internal quantum efficiency as high as 63 % under continuous-wave operation.