Effect of epitaxial-structure design and growth parameters on the characteristics of metamorphic lasers of the 1.46-$\mu$m optical range based on quantum dots grown on GaAs substrates
Abstract:
The characteristics of lasers of the 1.44–1.46-$\mu$m optical range grown on GaAs substrates using a metamorphic buffer are studied. The active region of the laser contains 10 rows of InAs/In$_{0.4}$Ga$_{0.6}$As/In$_{0.2}$Ga$_{0.8}$As quantum dots. It is shown that the use of special selective high-temperature annealing along with the application of short-period In$_{0.2}$Ga$_{0.8}$As/In$_{0.2}$Al$_{0.3}$Ga$_{0.5}$As short-period superlattices makes it possible to substantially decrease the density of threading dislocations in the active region. A threshold current density of 1300 A cm$^{-2}$, external differential quantum efficiency of 38%, and maximal pulsed-mode output power of 13 W are attained for a laser with a broad area 3 mm in length.