Abstract:
X-ray structural analysis and photoluminescence spectroscopy techniques were used to study heterostructures based on InGaAs/InAlGaAs superlattice for active regions of 1300 nm range lasers grown by molecular beam epitaxy. It is shown that the grown heterostructures have a high crystal quality. The perpendicular lattice mismatch of the average crystal lattice constant of the InGaAs/InAlGaAs superlattice with respect to the crystal lattice constant of the InP substrate is estimated at $\sim$+0.01%. An analysis of the photoluminescence spectra made it possible to conclude that the contribution of Auger recombination is insignificant in the studied range of excitation power density. Studies of vertical-cavity surface-emitting lasers with an active region based on the InGaAs/InAlGaAs superlattice made it possible to estimate the gain coefficient at a level of 650 cm$^{-1}$ for the standard logarithmic approximation of the dependence of the gain on the current density. The transparency current density of the laser was $\sim$150 À/cm$^2$, which is comparable to the record low values for the case of highly strained InGaAs–GaAs and InGaAsN–GaAs quantum wells in the spectral ranges of 1200 nm and 1300 nm, respectively.