On Laser-induced Damage Features in an Ultraviolet (UV) Fluorophosphate Glass When Irradiated with a Nanosecond Laser Beam

In this study a novel ultraviolet (UV) window material, fluorophosphate glass, was prepared by the melt-quenching method. The laser-induced damage (LID) feature of fluorophosphate glass was measured using laser damage experiments, atomic force microscopy (AFM), and scanning electron microscopy (SEM). The results show that fluorophosphate glass has a high ultraviolet transmittance (88%) at 351.00 nm. And the laser-induced damage threshold (LIDT) of the fluorophosphate glass is almost 7.0 J/cm(2), which is more than 2 times higher than that of fused silica (3.2 J/cm(2)) irradiated with a 8 ns and 351.00 nm laser by the same processing method. In addition, AFM and SEM images indicate that the damage is also insensitive to the surface roughness of fluorophosphate glass.