Low-threshold GaInNAsSb quantum well lasers

Long wavelength-GaInNAsSb quantum well lasers that include small amount of Sb were successfully grown by gas-source molecular beam epitaxy (GSMBE). We confirmed that Sb reacts in GaInNAs/GaAs system like a surfactant, which increase the critical thickness at which the growth mode changes from the 2-dimensional (2-D) growth to the 3-dimensional (3-D) growth. The GaInNAsSb/GaAs lasers oscillated under CW operation at 1.258micrometers at room temperature. The low CW threshold current of 12.4mA and high characteristic temperature (T ( )) of 157K were obtained for GaInNAsSb/GaAs lasers, which is the best result for GaInNAs- based narrow stripe lasers. To extend the lasing wavelength over 1.3micrometers with keeping the threshold density low, we adopted GaNAs barriers instead of GaAs barriers. We obtained the very low threshold current density of 570A/cm 2 at 900micrometers -long cavity with the lasing wavelength of 1.308micrometers . We can say that GaInNAsSb lasers are very promising material for realizing peltier-free devices for access network.