High-harmonics from a UV laser plasma

The generation of high-harmonics in laser-plasma interactions on the steep density gradients is discussed, especially by using short pulse UV laser radiation. Low intensity experiments with 5 • 1015W/cm2 showed high harmonics in the VUV range and the efficiency could be optimized by modifying the density gradient. The disagreement among different experiments and the lack of a full theoretical understanding of the generation mechanism forced us to switch for higher intensities. The experimental arrangement for obtaining 5 • 1017W/cm2 intensity with low-prepulse using a table-top system is shown. Preliminary results and future trends for high-harmonics generation with this method is given.