Efficient Coupling of High-Intensity Sub-Picosecond Laser Pulses into Solid Grating Targets

Abstract

We have experimentally observed very efficient laser-solid coupling of high-intensity (1016Wcm–2) sub-picosecond (150 fsec) laser pulses into grating targets.1 This behavior is in contrast to the very high reflectivities observed from flat targets,2 where we have recently extended our measurements of normal-incidence flat-target reflectivities up to incident intensities exceeding 1016 W cm–2. The average flat target reflectivity observed was 86% - the peak reflectivity at the center of the focal spot and peak of the laser is therefore ≥ 90%. This data is shown in Fig. 1.