Feature

High Power Mid-IR Interband Cascade Lasers

R.Q. Yang, C-H. Lin, B.H. Yang, D. Zhang, S.J. Murry, and S.S. Pei, Space Vacuum Epitaxy Center, Univ. of Houston, Tex.; C.L. Felix, W.W. Bewley, I. Vurgaftman, and J.R. Meyer, Naval Research Laboratory, Washington, D.C.; and A.A. Allerman and S.R. Kurtz, Sandia National Laboratories, Albuquerque,NM

Mid-IR lasers are in demand for a number of commercial, space, and military applications. These include trace gas detection, IR counter measures, IR light detection and ranging (LIDAR) systems, laser surgery, and medical diagnosis. We have recently demonstrated a new type of mid-IR quantum cascade (QC) laser based on interband transitions in type-II quantum wells. This interband cascade (IC) laser takes advantage of the broken-gap band alignment in the InAs/Ga(In)Sb heterostructure to recycle electrons from the valence band back to the conduction band (see Fig. 1), thus enabling sequential photon emissions from active regions stacked in series. However, by sticking to the interband transitions, it circumvented the fast phonon scattering, which limits the performance of devices based on intersubband transitions such as the QC lasers.