Abstract:
The conventional tilted-pulse-front (TPF) setup is one of the most promising methods to generate few-cycle terahertz pulses. Due to the noncollinear phase matching condition and the asymmetry of the prism-shaped nonlinear crystal geometry, the generated terahertz pulses possess large spatial inhomogeneity. In order to fully investigate the terahertz generation process in the TPF scheme, a 3-D numerical model is required. In this presentation, we compare the differences of the 1-D, 2-D, and 3-D numerical models. The simulations suggest that the diffraction and beam size at the dimension perpendicular to the pulse-front-tilt plane has a negligible influence on the terahertz generation process. In contrast, the beam size within the pulse-front-tilt plane largely influences the generated terahertz electric field and the conversion efficiency. To conclude, a strong spatial dependence on the terahertz electric field is found and the few-cycle region is only generated around the apex of the prism.