Measurement of logarithmic gain coefficient (G0) and temperature sensitivity in gaas/aigaas quantum well lasers

Due to gain saturation effects, the gaincurrent density curve in QW lasers is better approximated by a logarithmic than a linear curve. (Γg = G₀ ln(ηi J/J₀)). We report on the determination of the logarithmic gain coefficient (G₀) for QW lasers, from single pass gain measurements. We show that G₀ scales well with the number of quantum wells. These G₀ values are compared with the values obtained from a logarithmic fit to the theoretical gain-current density curves. The temperature dependence of single pass gain is also investigated and was found to increase with G₀.