Theory of terahertz pulse generation through optical rectification in a nonlinear optical material with a finite size

The full analytical solutions for plane terahertz waves generated through optical rectification in a slab of a nonlinear optical material are calculated. Terahertz dispersion, absorption of both optical and terahertz waves, and multiple reflections are considered. The results are valid for an arbitrary difference between the optical group index and the terahertz refractive index, including equal indices. It is demonstrated that the full terahertz wave is freely propagating and has no contribution of a 'forced' pulse.