A novel-type tunable and narrowband extreme ultraviolet radiation source based on high-harmonic conversion of picosecond laser pulses

At the Laser Centre Vrije Universiteit a table-top size, tunable and narrowband laser-based source of extreme ultraviolet radiation was developed using high-harmonic generation of powerful laser pulses of 300 ps duration and Fourier-transform limited bandwidth. The generated radiation has unprecedented spectral purity of ?/??>2.5×105 at wavelengths covering the entire tunability range of 40-100 nm. The process of high-order harmonic generation was investigated in different gases (Ar, Kr, Xe, N 2) uncovering resonance phenomena for the conversion efficiency of specific harmonic orders.