Continuous wave operation of quantum cascade lasers at room temperature

Summary from only given. We present buried heterostructure QC lasers with a four quantum well (QW) active region designed for emission at 9.1 /spl mu/m with an improved waveguiding scheme and better heat dissipation for high temperature CW operation. The four quantum well design makes use of short lifetime of the lower lasing state and the good injection efficiency into the upper lasing state. The laser structure is grown by molecular beam epitaxy (MBE) using ternary InGaAs and InAlAs alloys lattice matched to an n-doped InP substrate. The QC laser active material consists of 35 periods, each comprising a partially n-doped injector region and the undoped four QW active region, embedded in an optical waveguide.