Organometallic vapor phase epitaxy of high-performance strained-layer InGaAs-AlGaAs diode lasers

Abstract

Graded-index separate-confinement heterostructure single-quantum-well lasers incorporating a strained In/sub x/Ga/sub 1-x/As active layer, with x<or=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/sub th/ is reduced from 550 A/cm/sup 2/ for structures without bounding layers to 125 A/cm/sup 2/ for structures with 10-nm-thick bounding layers, while the differential quantum efficiency eta /sub d/ is increased from 46 to 80%.<<ETX>>