Gain-current calculations for bulk GaInP lasers including many-body effects

The gain-current characteristics of undoped GaInP (660-nm) bulk lasers have been calculated over a range of temperatures. The calculations use parabolic bands with strict k selection and include band-gap narrowing and lifetime broadening due to carrier-carrier interactions at high densities. The broadening lifetime τ has been implemented as a constant value of 10−13 s and as a carrier-dependent value proportional to n−1/3. Using τ=10−13 s, our calculations for GaInP at room temperature give a value for the differential gain β of 0.026 cm−1 (A cm−2 μm−1)−1 and a value for the transparency current J0 of 4.4 kA cm−2 μm−1. These are in close agreement with experimental results. Results for GaAs at room temperature are also given.