Aberration-free high-harmonic source generated with a two-colour field

作者：Lambert G^*; Tissandier F; Gautier J; Hauri C P; Zeitoun P; Valentin C; Marchenko T; Goddet J P; Ribiere M; Sardinha A; Fajardo M; Hamouda F; Maynard G; Rey G; Sebban S

来源：EPL, 2010, 89(2): 24001.

DOI：10.1209/0295-5075/89/24001

Imaging experiments of ultrafast phenomena of matter at nanometre-scale require intense, short pulse duration and diffraction-limited soft-X-ray beams, nowadays almost only provided by free-electron lasers. Here, we focused on a table-top soft-X-ray source, which fulfils these fundamental criteria and in addition presents high temporal coherence, the high harmonics generated with a two-colour field (omega + 2 omega). These harmonics revealed to be free from aberration just by slightly spatially filtering the laser used for generation (omega). Indeed, the measured wavefront distortions, equal to lambda/17 RMS at 44 nm, correspond to a diffraction-limited beam. This behaviour is explained by an additional spatial nonlinear filtering effect of the driving laser wavefront, induced here in our particular but simple geometrical configuration of generation by the 2 omega component.

• 出版日期2010-1