Interband cascade (IC) lasers take advantage of the broken band-gap alignment in type-II quantum wells to reuse injected electrons in cascade stages for photon generation with high-quantum efficiency, while retaining interband transitions for photon emission without involving fast phonon scattering. Over the past several years, significant progress has been made in developing efficient IC lasers, particularly in the 3-4 μm region where continuous wave (cw) operation was achieved at above room temperature with low power consumption. In this paper, we report our recent efforts in the development of IC lasers at longer wavelengths (4.3-7.5 μm) based on InAs substrates and plasmon-waveguide structures. Cw operation of plasmon-waveguide IC lasers has been achieved at temperatures up to 184 K near 6 μm. Also, improved thermal dissipation has been demonstrated with the use of the plasmon waveguide structure.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.