Mid-IR interband cascade lasers

Summary form only given. The mid-IR interband cascade laser is based on optical transition between the conduction and valence bands in type-II QW structures such that the fast phonon scattering loss in intersubband QC lasers can be circumvented, while retaining the advantages of cascaded tunneling injection and wavelength tailoring. Here, we report an interband cascade laser at 3.85 /spl mu/m with a threshold current density significantly lower than previously reported.