Summary form only given. We show how a laser resonator design exploiting chaotic ray motion can dramatically increase output power and directionality of whispering gallery lasers. This effect is demonstrated in quantum cascade (QC) lasers, which are based on mid-infrared intersubband transitions.

Summary form only given. Quantum cascade (QC) lasers are a new type of semiconductor laser for the mid-infrared based on electronic intersubband transitions. Because of their high power output and above room temperature (RT) operation, QC lasers are prime candidates for laser-based portable and stand-alone environmental monitoring systems. For gas spectroscopy the lasers have to operate with stable single-mode emission and controlled ...

Summary form only given. Planar waveguides for long-wavelength quantum cascade (QC) lasers require thick cladding layers. This prolongs and complicates the growth and processing procedures of these lasers. In this paper we demonstrate that optical waveguiding for a laser in this wavelength range can also be achieved using electromagnetic surface waves at a metal-semiconductor interface directly above the active region of the laser. No ...