Mid-infrared InAsAlGaSb superlattice quantum-cascade lasers

We report on the demonstration of mid-infrared InAsAlGaSb superlattice quantum-cascade lasers operating at 10 μm. The laser structures are grown on n-InAs (100) substrate by solid-source molecular-beam epitaxy. An InAsAlGaSb chirped superlattice structure providing a large oscillator strength and fast carrier depopulation is employed as the active part. The observed minimum threshold current density at 80 K is 0.7 kA cm2, and the maximum operation temperature in pulse mode is 270 K. The waveguide loss of an InAs plasmon waveguide is estimated, and the factors that determine the operation temperature are discussed.