Threshold current of 670-nm AlGaInP strained quantum well lasers

By means of gain-current calculations we have examined the factors which determine the threshold current of compressively strained Ga/sub x/In/sub 1-x/P/AlGaInP quantum well lasers for the various well width/composition (x) combinations which give a transition wavelength of 670 nm. In addition to valence band modifications we find that the increasing depth and decreasing width of the well are important in decreasing the current as the strain increases. We reveal the important role of well width fluctuations in devices with high compressive strain.>