Channeled-Substrate GaAs/AlGaAs Multiple Quantum-Well Lasers Grown by Molecular Beam Epitaxy

Abstract

Single and multiple quantum-well (MQW) lasers have been extensively investigated1,2. Besides their low threshold current density, these quantum-well heterostructure lasers exibit good linearity in light-output versus current characteristics, a high external differential quantum efficiency, and a high value of To which is a measure of lesser temperature sensitivity. To date, however, there have been few studies3,4 concerning the index-guiding of these quantum-well lasers which is of great interest for practical applications. For fiber-optical communications at high data rates, the control and stability of the lasing modes have become of great concern. Although it is commonly believed that crystal growth using molecular beam epitaxy (MBE) reproduces substrate features with uniform thickness, we have found that growth is sufficiently inhomogeneous to produce thickness variation in the epilayer over the channels. From our laboratory, we have reported the achievement of a single-longitudinal-mode operation of AlxGa1−xAs/GaAs simple double-heterostructure (DH) lasers made by MBE over the channels along [110] direction which provides for lateral modes stabilization. In this paper, we are going to present the fabrication processes and the characteristics of channeled-substrate AlxGa1−xAs/GaAs MQW lasers grown by MBE.