Midinfrared type-II interband cascade lasers

We describe the progress made in the development of type-II interband casca de lasers emitting in the midinfrared (3.8-3.9 mu m) spectral region. Three nominally similar molecular beam epitaxy growths on substrates from differ ent vendors show qualitatively different electrical and optical properties. The devices tested show significant improvements over previously reported results with respect to differential external quantum efficiency (similar t o 500%), peak power (>4 W/facet), peak power conversion efficiency (similar to 7%), maximum operating temperature (217 K), and continuous-wave operati on.