Abstract

InGaAs-GaAs-AlGaAs strained layer quantum well heterostructure laser diodes offer the availability of emission wavelengths in the 0.9-1.1-μm range otherwise largely inaccessible with conventional lattice matched semiconductor diode lasers. In particular, these lasers are attractive as small, efficient, low cost pump sources for rare earth doped glasses. We describe here high efficiency, low threshold, reliable InGaAs-GaAs strained layer lasers and laser arrays^1,2 grown by³ atmospheric pressure metal-organic chemical vapor deposition (MOCVD). The growth conditions for preparing these strained layer structures by MOCVD are outlined, including data on reproducibility in quantum well size and composition and information on the long term stability of In-alkyl precursors. Time-zero characterization of oxide defined stripe broad area lasers as a function of InGaAs layer composition and thickness, particularly in relation to the critical thickness for accommodating strain elastically, is presented as a baseline for comparison to more sophisticated devices. Various laser structures, grown throughout the 0.9-1.1-μm wavelength range and having In mole fractions from x = 0-0.50, are shown, as in Fig. 1, to have the low broad area threshold current densities (J_th < 200 A/cm²) and other desirable characteristics of unstrained quantum well heterostructure lasers.

© 1990 Optical Society of America