Diode lasers with Al-free quantum wells embedded in LOC AlGaAs waveguides between 715 nm and 840 nm

In this paper, we present results on diode lasers in the wavelength range between 715 nm and 840 nm with Al-free QWs which are embedded in a high-quality AlGaAs LOC broadened waveguide structure with low optical loss and a small vertical far field divergence. The laser structures were grown by LP- MOVPE. We studied tensile-strained GaAsP-QWs as well as compressively strained InGaAsP-QWs with strain compensating barriers. For lasers with GaAsP QWs, the lowest transparency current densities of about 130 A/cm 2 were obtained in the wavelength range between 750 nm and 800 nm. Very low transparency current densities were achieved with InGaAsP-QWs at wavelengths above 800 nm. At 810 nm, high output powers (100 micrometer aperture) of about 7 W was achieved with both types of QWs from devices mounted epi up. However, with respect to high temperature operation and reliability tensile- strained GaAsP QWs seem to be the better choice, especially for the wavelength range below 760 nm.