Measurement and calculation of gain spectra for (GaIn)As/(AlGa)As single quantum well lasers

The gain spectrum of a (GaIn)As/(AlGa)As single-quantum-well laser diode is precisely measured at various currents in order to quantitatively check the predictions of a microscopic model. The theory includes carrier—carrier and carrier—LO-phonon collisions which lead to optical dephasing and screening of the Coulomb interaction. The measurements are based on a transmission technique using the broad spectrum of a 10 fs Ti:sapphire laser to obtain sufficient signal to noise ratio over a wide spectral range. We obtain excellent agreement between theoretical and experimental gain spectra and thus can clearly demonstrate the predictive capability of our microscopic model.