Fig. 1: The testbed platform.
a Experimental setup of the testbed platform: The pump laser with a pulse energy Elaser, a pulse duration τlaser, and a peak intensity Ilaser interacts with a cylindrical hydrogen-jet target. Time-resolved high-resolution shadowgraphy utilizes a single microscope and two simultaneous backlighters with a pulse duration of 260 fs (258 nm probe) and 160 fs (515 nm probe). b Showcase with Elaser = 160 mJ, τlaser = 37 fs, and Ilaser = 1.6 × 1018 Wcm−2: Exemplary shadowgrams of a time-delay scan as recorded by the 258 nm probe. The pump-probe delay is given in the upper-right corner of each shadowgram and the shadow diameter \({D}_{{{{{{{{\rm{E}}}}}}}}}^{258\,{{{{{{{\rm{nm}}}}}}}}}\) is measured between the cyan arrows. For 30 ps delay, volumetric transparency is observed. The spatial extent and fluence of the parasitic plasma emission vary from shot-to shot. The colorscale and spatial scale are consistent between the images.
