Analysis of intensity modulation characteristics of quantum well lasers with carrier heating and carrier transport effects

A simple model is developed to describe hot carriers, hot phonons, carrier transport effects on intensity modulation response of quantum well lasers. It is shown that for modulation frequencies smaller than the inverse of phonon lifetime, the contribution to the response function from phonon heating can be characterized by a time constant for electron temperature relaxation and phonon number modulation factor. At small photon densities analytical expressions for the K-factor and the nonlinear gain coefficient are derived. A new mechanism is described that may limit modulation bandwidth due to multiplicative effect of carrier heating and carrier overflow. It is demonstrated that in the absence of carrier overflow, the dependences of the K-factor on the carrier density are determined mainly by hot phonon effects. At high modulation frequencies, carrier injection heating influence strongly on the intensity modulation response resulting in an increase of the modulation bandwidth under large band-gap offsets. Electron capture time is calculated taking into account intersubband transitions. Using our approach decreased amplitude of the oscillations in the capture time versus the well thickness and depth was obtained.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.