Carrier capture in type-II quantum wells for optically pumped mid-infrared lasers

Summary form only given. Type-II InAs-GaInSb quantum structures are attractive as the active regions in mid-infrared lasers, because they can be grown with bandgaps throughout the mid-infrared, engineered with suppressed Auger recombination and intersubband absorption, and grown lattice-matched to GaSb substrates. The efficiency of these lasers depends on the rapid transfer of carriers into the wells from the thick GaInAsSb barrier regions, which serve as separate absorbers for the 2-/spl mu/m pump. The capture rate can be investigated by exciting carriers into the barriers with an ultrafast pulse and then measuring the rise-time of the photoluminescence (PL) from the wells. The variation of the rise-time with excitation density and sample temperature yields information about the capture process.