Effect of PVA coating on the electric field intensity distribution and laser damage performance of fused silica optics surfaces

A facile method was proposed to enhance the laser damage performance of the fused silica optics by coating a PVA film on the rear surface of the optics. FDTD simulation result suggests that the PVA coating with suitable thickness can transfer the maximal electric field intensity from the rear surface to the interface between the coating and air, and reduce the electric field intensity of the rear surface remarkably. LIDT tests reveal that the LIDT of fused silica with PVA coating changed periodically with respect to the coating thickness, which agrees well with the tendency predicted by FDTD simulation. Finally, PVA coatings with a thickness of 60 nm and 300 nm can both improve the LIDT of AMP-treated fused silica by ~20%, which provide a potential to be applied in high power laser facility.