On Bridging the Terahertz Gap Using Four-Wave Mixing in Photonic Crystal Fibers

A newly introduced computationally-efficient FDTD model of pulse propagation in photonic crystal fibers, which accounts for both mode dispersion and third-order nonlinear properties of applied materials, is used in this paper to the study of the electrodynamics of terahertz generation with four-wave mixing of two co-propagating femtosecond pulses. Basic requirements for efficient conversion of energy, related to such parameters like group velocity dispersion, are specified. The impact of the transmission line characteristics and pulse properties on both spectral and time evolution of the generated terahertz radiation are shown and discussed. The obtained results pave the way for further rigorous studies heading toward bridging a terahertz gap with the aid of broadly available high-power femtosecond laser sources supplemented with dispersion-engineered photonic crystal fibers.