Long wavelength interband cascade lasers

InAs-based interband cascade lasers (ICLs) can be more easily adapted toward long wavelength operation than their GaSb counterparts. Devices made from two recent ICL wafers with an advanced waveguide structure are reported, which demonstrate improved device performance in terms of reduced threshold current densities for ICLs near 11 mu m or extended operating wavelength beyond 13 mu m. The ICLs near 11 mu m yielded a significantly reduced continuous wave (cw) lasing threshold of 23 A/cm(2) at 80 K with substantially increased cw output power, compared with previously reported ICLs at similar wavelengths. ICLs made from the second wafer incorporated an innovative quantum well active region, comprised of InAsP layers, and lased in the pulsed-mode up to 120 K at 13.2 mu m, which is the longest wavelength achieved for III-V interband lasers.