Asymmetric, nonbroadened large optical cavity waveguide structures for high-power long-wavelength semiconductor lasers

We present a simple semianalytical model for evaluating the free-carrier loss in the waveguide layer of large-cavity semiconductor lasers, which proves that these losses may become an important factor at high bias currents. It is shown that nonbroadened asymmetric waveguide structures can significantly reduce these losses when compared to broadened symmetric waveguides, with little or no degradation in threshold, near- and far-field properties, and are thus a promising configuration for high-power lasers operating high above threshold.