Effect of interface structure on the optical properties of InAs/GaSb laser active regions

Abstract
We present calculations of the fundamental band gap and intervalence absorption in InAs/GaSb materials incorporating both the intrinsic atomistic symmetry of interface bonding and typical compositional gradients near the interfaces. Including these effects quantitatively explains experimentally observed systematic trends in the band gaps of InAs/GaSb superlattices. Calculations of intervalence absorption indicate that the internal loss in laser active regions based on these materials can not be predicted quantitatively without including these effects.