Waveguide design optimization for a quantum cascade laser emitting at 77 μm

The dependence of waveguide design parameters on the performance of a GaAs/AlGaAs quantum cascade laser emitting at View the MathML source is theoretically evaluated. We propose a new waveguiding scheme for modal confinement at such long wavelengths. An artificially tailored index layer and a plasmon enhanced layer act as the cladding at the top and bottom of the active region, respectively. The cladding layers have been made aluminum free to avoid the presence of DX centers. The waveguide design is optimized to enhance modal confinement and reduce waveguide losses. Finally, we present an optimized design of the quantum cascade laser in its entirety along with expected performance characteristics.