Terahertz Generation Setups using Segmented Tilted-Pulse-Front Excitation

Summay form only given. A very efficient way of generating high energy terahertz (THz) pulses is the tilted-pulse-front excitation in lithium niobate (LN). In the last decade drastic increase of the THz pulse energy was achieved by the continual development of this technique. However, the following factors are still strongly limit of its energy scalability and THz beam quality: limited interaction length due to angular dispersion (i), prism shape of the LN crystal (ii), and imaging errors (iii). In order to overcome (i) a setup using a reflective echelon instead of optical grating was proposed [1], in which a segmented pump pulse front with adequate average tilt angle ensures the necessary velocity matching. However, (ii) and (iii) remained unsolved. A plan parallel structured nonlinear echelon slab (NLES) [2] can solve (ii) and significantly reduce (iii) keeping the same efficiency as available with the conventional setup as shown by blue and red curves in Fig. 1(a). Advantageously this setup allows energy scalability and good focusability. Working principle and single-cycle THz waveform was demonstrated with this setup [3].