Transient grating measurement of in-plane ambipolar diffusion in a 4-micron-band-gap, four-layer superlattlce

Summary form only given. We describe time-resolved transient grating measurements of in-plane ambipolar transport in a narrowband-gap superlattice that has a period comprised of four layers: InAs/GaInSb/InAs/AlGaInAsSb. The structure was designed as an active region for mid-infrared semiconductor lasers. Two 140-fs, 840-nm pulses from a mode-locked Ti:sapphire laser were interfered in the superlattice to create the transient grating, which was subsequently interrogated in a time-resolved manner by diffraction of a weak, mid-infrared, 160-fs probe pulse. The diffraction efficiency was measured at 300 K as a function of time-delay, grating period, and carrier density.