1.6 W high wall plug efficiency, continuous-wave room temperature quantum cascade laser emitting at 4.6 mu m

A strain-balanced, InP-based quantum cascade laser structure designed for light emission at 4.6 mu m was grown by metal-organic chemical vapor deposition. A maximum total optical power of 1.6 W was obtained in continuous-wave mode at 300 K for uncoated devices processed in buried heterostructure geometry with stripe dimensions of 5 mm by 9.5 mu m. Corresponding maximum wall plug efficiency and threshold current density were measured to be 8.8% and 1.05 kA/cm(2), respectively. Fully hermetically packaged laser of identical dimensions produced in excess of 1.5 W under the same conditions. (C) 2008 American Institute of Physics.