Abstract:

A strain-balanced, InP-based quantum cascade laser structure, designed for light emission at 4.6 mu m using a new nonresonant extraction design approach, was grown by molecular beam epitaxy. Removal of the restrictive two-phonon resonant condition, currently used in most structure designs, allows simultaneous optimization of several design parameters influencing laser performance. Following the growth, the structure was processed in buried heterostructure. Maximum single-ended continuous-wave optical power of 3 W was obtained at 293 K for devices with stripe dimensions of 5 mm x 11.6 mu m. Corresponding maximum wallplug efficiency and threshold current density were measured to be 12.7% and 0.86 kA/cm(2). (C) 2009 American Institute of Physics. [doi: 10.1063/1.3238263]