High-temperature interband cascade lasers emitting at λ=3.6-4.3 μm

The authors report the operating characteristics of ten-stage interband cascade lasers from two wafers with room-temperature wavelengths of 4.1 and 4.3 mu m. For 150-mu m-wide stripes, the threshold current densities are as low as 4.8 A/cm(2) at 78 K (cw) and 1.15 kA/cm(2) at room temperature (pulsed). At 78 K, the cw wall-plug efficiency for an 11-mu m-wide ridge with 0.5-mm-long cavity and coated facets is 27%, while a 3-mm-long cavity emits a maximum cw power of 200 mW. Devices from the two wafers have maximum cw operating temperatures of 261 K (lambda approximate to 4.0 mu m) and 243 K (lambda approximate to 4.2 mu m). (c) 2007 American Institute of Physics.