New nonlinear parametric conversion mechanism for coherent THz generation

We propose a new nonlinear mechanism for coherent THz generation in cubic media. We show that this phenomenon can be presented only by χ(3) parametric process without inclusion of χ(2) processes. In this work we consider the particular case of generation of THz signal from femtosecond laser pulses propagating in optical fibers (fused silica). On the base of proposed theoretical model we derive a system of nonlinear partial differential equations investigated numerically by means of the split-step Fourier method. The numerical results show a significant coherent THz generation when the dispersion is negligible.We propose a new nonlinear mechanism for coherent THz generation in cubic media. We show that this phenomenon can be presented only by χ(3) parametric process without inclusion of χ(2) processes. In this work we consider the particular case of generation of THz signal from femtosecond laser pulses propagating in optical fibers (fused silica). On the base of proposed theoretical model we derive a system of nonlinear partial differential equations investigated numerically by means of the split-step Fourier method. The numerical results show a significant coherent THz generation when the dispersion is negligible.