Enhanced extreme ultraviolet emission from a transverse profile-tailored laser-driven preformed tin disk targets

Highly efficient in-band extreme ultraviolet (EUV) generation from a confined plasma, produced by a 1-μm wavelength transverse-profile-tailored laser-irradiated preformed disk target, has been demonstrated via radiation hydrodynamic simulations. The tailored laser exhibits a crater-like intensity profile, with a lower intensity at the center and a higher intensity in the surrounding annular region. It is found that such an intensity profile can confine plasmas by driving inward plasma flow, which induces ion density accumulation. The confined plasma can effectively convert part of the expanding plasma kinetic energy into thermal energy for further radiative energy conversion. Further investigations into the in-band radiation emissivity and optical depth show that although the self-absorption effect in the confined plasma is relatively significant, the increase in emitter density ultimately boosts the final conversion efficiency (CE). Eventually, the light source generated by the tailored laser achieves a CE of 4.1%, which is 20% higher than that of the Gaussian laser (3.5%) under the same conditions. This study highlights a promising pathway for advancing efficient EUV source generation by modulating the laser transverse profile.