GROWTH AND ASSESSMENT OF INGAAS/INGAALAS/INP MULTIPLE QUANTUM-WELL LASERS

Atmospheric pressure MOCVD has been used to produce long wavelength MQW SCH lasers incorporating InGaAs quantum wells in an InGaAlAs waveguide surrounded by InP cladding regions. Emission wavelengths from 1.26 to 1.61-mu-m were obtained by varying the quantum well width from 20 to 140 angstrom. For lasers operating at wavelengths around 1.5-mu-m the lowest threshold current density observed was 820 A/cm2. A CW output of over 30 mW was obtained at 300 mA, with emission only in the TE mode. These are the best values for 1.5-mu-m wavelength lasers using the InGaAlAs quarternary alloy reported so far, in spite of compositional non-uniformity in the quaternary alloy revealed by transmission electron microscopy.