Generation of arbitrary terahertz wave forms in fanned-out periodically poled lithium niobate

The authors demonstrate a flexible terahertz pulse-shaping technique, manipulating spatially dispersed multifrequency components generated by optical rectification in a fanned-out periodically poled lithium niobate crystal. Spatial masks of low pass, high pass, and double slit in front of the crystal manipulate the spatial pattern of the optical excitation beam on the crystal, which is mapped onto the intensity profile of the terahertz spectrum. The spatial dispersion of the terahertz spectrum is removed by the line-to-point imaging of a spherical mirror.