We derive model equations for the propagation of ultrashort pulses in materials with resonant linear and quadratic nonlinear responses and find approximate soliton solutions describing all-bright and dark-bright polaritons. We report the specific phase matching condition for efficient 2nd harmonic generation, which involves detuning from the resonance. We also demonstrate that the 2nd harmonic ...

Converters are used in the utility interface of renewable energy system to reduce harmonic contents in line current/voltage and to increase reliability. These converters suffer from high level of Total Harmonic Distortion (THD) in the utility line currents/voltages which creates a lot of problems in the power system. In this paper selective harmonics are eliminated to reduce the THD, that is, t...