Continuous wave operation of quantum cascade lasers

We present buried heterostructure quantum cascade lasers with a four quantum well (QW) active region based on a double phonon resonance and with an improved waveguiding scheme and better heat dissipation for high temperature CW operation. The laser structure is grown by molecular beam epitaxy (MBE) using ternary InGaAs and InAlAs alloys lattice matched to an n-doped InP substrate.