Comparison of experimental and theoretical gain-current relations in GaInP quantum well lasers

Summary form only given. AlGaInP quantum well (QW) lasers (620-690 nm) that satisfy the performance required for applications such as digital versatile disk and photodynamic therapy are still difficult to design. To progress we need a good description of the gain and to understand which recombination mechanisms are significant. We performed experiments at 300 K on 670-nm lasers, conditions where thermally activated leakage current is small. The structure consists of a 6.8-nm-wide, compressively strained, Ga/sub 0.41/In/sub 0.59/P QW in an (Al/sub 0.5/Ga/sub 0.5/)/sub 0.51/In/sub 0.49/P waveguide core and clad with (Al/sub 0.7/Ga/sub 0.3/)/sub 0.51/In/sub 0.49/P. We determined gain spectra and quasi-Fermi level separation from experimental transverse electric (TE) spontaneous emission spectra. The measurements were converted into real units by experimentally determining the threshold loss.