Single-shot laser-induced damage threshold of free-standing nanometer-thin diamond-like carbon foils

Single-shot laser-induced damage threshold (LIDT) of free-standing nanometer-thin diamond-like carbon (DLC) foils was measured in vacuum environment for pulse durations from 50 fs to 200 ps. It is found that, due to higher surface defects density, the LIDT of free-standing ultrathin DLC foils is lower than that of bulk DLC by a factor of 3, and the damage fluence is almost a constant of about 0.1 J/cm2 when the pulse duration is longer than 500 fs. Different from DLC films coated on silicon wafer, the damage fluence of free-standing DLC has a weak dependence on their thickness. Based on the measurement, the damage mechanism is illustrated by virtue of the carrier population analysis, and the requirement on the temporal laser contrast when DLC targets are used in relativistic laser-plasma experiment is discussed.