Preparation and analysis of laser heterostructures in InGaAsP/GaAs and InGaAsP/InP with wave emission between 0.8 and 1.3 micrometers

The present work reports about the fabrication and investigation of InGaAsP/InP and InGaAsP/GaAs lasers heterostructure with wavelength of 1.3 and 0.8 mu m, respectively. We propose a method based on the concept of solubility to determine the distribution of the temperature in the oven along the graphite boat. That permits to know the temperature immediatly in the interface between the liquid phase and the substrate. This procedure together with a series of measurements of X-ray diffraction and photoluminescence spectra allows to simplify the optimization of the composition of the layers forming the heterostructure. The modified growth technology method by liquid phase epitaxy is described in detail. Using a especial construction of the graphite boat allows to grow the layers with the thickness down to 50 Angstrom. We did a comparative analysis of a laser double heterostructure and a separate confinement heterostructure. The best threshold current densities were 270 and 370 A/cm(2) for the heterostructures with the wavelength of 0.8 and 1.3 mu m, accordingly. These magnitudes are comparable with the threshold current densities reported early in different articles for equivalent structures.