High performance single mode GaAs quantum cascade lasers

Abstract

We report on the realization of distributed feedback quantum cascade lasers in the AlGaAs/GaAs material system. Strong coupling is achieved by the use of a metalized surface relief grating, allowing the realization of short lasers. Continuous wave operation was achieved for an AlAs/GaAs chirped superlattice laser with an emission wavelength of 11.8 μm . The used double plasmon enhanced optical waveguide consists only of the binary material GaAs and not of a ternary compound which results in a small thermal resistance. Further, the emission wavelength of the distributed feedback laser is continuously tunable according to the temperature dependence of the refractive index. Additionally, we want to report about pulsed single mode operation up to 335 K for a laser material, where Al 0.45Ga 0.55As is used for the barriers and GaAs for the wells. The emission wavelength is 9.5 μm and the optical peak power in pulsed mode operation from one facet of the distributed feedback laser is 0.3 W at a temperature of 0°C.