Very low internal loss, 1.5 /spl mu/m wavelength SCH-MQW InGaAsP/InP laser diodes with broadened-waveguides

We have shown that the cladding layer free-carrier absorption is the main source of internal loss in the studied InGaAsP/InP SCH-MQW laser structures. Very low internal loss (1.3 cm/sup -1/) and low threshold current density (260 A/cm/sup 2/ for a 2 mm cavity) are obtained with the broadened-waveguide laser structure. High efficiency lasers can be made using this structure.