Application of the Digital Alloy Composition Grading Technique to StrainedInGaAs/GaAs/AlGaAs Diode Laser Active Regions

摘要

Molecular beam epitaxy growth, lasing performance and transmission electronmicroscopy of ln(0.25)Ga(0.75)As asymmetric triangular quantum well (ATQW) active regions is reported. The digital alloy technique was utilized to form three active regions of widths 200 A, 300 A and 400 A. Plan view and cross-sectional TEM results indicate defect free material for the 200 A and 300 A wells while the 400 A well exceeded the critical layer thickness, exhibiting a high defect density. Each structure lased with a threshold current density of 313 A/sq cm,