Laser-induced damage properties of antireflective porous glasses

In this paper, porous nanostructures on BK7 glass were manufactured by chemical treatment in order to obtain antireflection (AR) components with improved laser damage resistance. The damage-resistant properties of the samples with nearly 100% transmittances at three pulsed laser wavelength were investigated. The damage tests showed that the BK7 glass with AR nanostructures can achieve the LIDTs of 58J/cm(2), 20 J/cm(2) and 12 J/cm(2) under the irradiation of 12ns 1064nm pulses, 10ns 532nm pulses and 8ns 355nm pulses, respectively. These values are much higher than those of AR coated glasses, but are almost the same level of un-etched substrate. The effect of structural properties on electric field distribution of porous surface was investigated by a three-dimensional (3D) finite difference time-domain (FDTD) model. The simulation results and the morphology of damage site on porous glass are compared to those of un-etched surface, and are discussed to reveal the possible damage mechanism. Finally, some possible solutions to improve the LIDT are proposed.