GROWTH OF INALGAAS STRAINED-QUANTUM-WELL STRUCTURES FOR RELIABLE 0.8-MU-M LASERS

Incorporation of indium into the quantum well materials of graded-inde x separate confinement heterostructure quantum well lasers has proven to be a key to imparting a much needed robustness to such lasers. By g rowing wells which contain both indium and aluminum along with gallium , operating wavelengths can be engineered to fall in the technological ly important range of 0.8 microns, appropriate for pumping Nd:YAG. The organometallic vapor phase epitaxial growth of these strained-layer s tructures faces extra challenges rooted in the competing influences on the energies of the quantized states. At a minimum, meeting wavelengt h targets requires achieving control of the quaternary composition and of the quantum well thickness. Because laser elements are relatively large, lateral uniformity of wavelength is a critical issue. Device pe rformance is influenced by basic material quality, which is a function of such fundamental growth parameters as temperature, V/III ratio, an d growth rate. We have grown InAlGaAs structures using various combina tions of growth conditions and well composition and thickness combinat ions, and evaluated and life-tested lasers in CW mode. The reactor's p erformance in achieving composition and thickness uniformity is report ed, as are data on the influence of the effects of growth conditions o n device performance.