Hybrid tilted-pulse-front excitation scheme for efficient generation of high-energy terahertz pulses

Conception of a hybrid type tilted-pulse-front pumping scheme for the generation of high-energy terahertz pulses is presented. The proposed setup is the combination of the conventional setup containing imaging optics and the contact grating. The solution was developed for nonlinear materials requiring large pulse-front-tilt angle, like LiNbO₃. Due to the creation of the pulse-front-tilt in two steps the limitations of imaging errors can be significantly reduced. Furthermore the necessary grating constant of the contact grating can be larger compared to the simple contact grating scheme making possible the fabrication of the grating profile with significantly higher precision. A detailed optimization procedure with respect to the diffraction efficiency on the contact grating is given for LiNbO₃. Instructions are also given how to construct the geometry of the setup in order to minimize imaging errors. Examples are given for LiNbO₃ based practically realizable, optimized schemes with reduced imaging errors and high diffraction efficiency on the contact grating.