CARRIER-GAIN DYNAMICS IN INXGA1-XAS ALYGA1-YAS STRAINED-LAYER SINGLE-QUANTUM-WELL DIODE-LASERS - COMPARISON OF THEORY AND EXPERIMENT/

We present measurements and calculations of femtosecond gain dynamics in InxGa1-xAs/AlyGa1-yAs strained-layer single-quantum-well diode lase rs using a multiple-wavelength pump-probe technique. To aid in the int erpretation of gain dynamics induced by both interband absorption and stimulated emission of photons, we develop a detailed theoretical mode l for gain dynamics in quantum-well laser diode structures and compare it with experimental measurements. In the model, transient gain and d ifferential transmission are computed in a multiband effective-mass mo del including biaxial strain, valence subband mixing, and polar-optica l-phonon scattering both within and between subbands. Transient photog eneration of electron-hole pairs by the pump pulse and subsequent rela xation of carriers by polar-optical-phonon scattering are calculated i n a Boltzmann-equation framework.