ORGANOMETALLIC VAPOR-PHASE EPITAXY OF HIGH-PERFORMANCE STRAINED-LAYER INGAAS-ALGAAS DIODE-LASERS

Graded-index separate-confinement heterostructure single-quantum-well lasers incorporating a strained In(x)Ga1-xAs active layer, with x less-than-or-equal-to 0.25, and AlGaAs confining layers have been grown on GaAs substrates by low-pressure organometallic vapor phase epitaxy. The emission wavelength increases from 0.85-mu-m for x = 0 to 1.03-mu-m for x = 0.25. The growth of GaAs layers bounding the InGaAs active layer significantly improves laser performance. For devices with x = 0.25 and a cavity length L of 500-mu-m, the pulsed threshold current density J(th) is reduced from 550 A/cm2 for structures without bounding layers to 125 A/cm2 for structures with 10-nm-thick bounding layers while the differential quantum efficiency eta-d is increased from 46 to 80%. For x = 0.25 and L = 1500-mu-m, J(th) = 65 A/cm2. Output powers as high as 1.6 W per facet and power conversion efficiencies as high as 47% have been obtained for continuous operation of lasers with x = 0.25 having uncoated facets.