Optical and Laser-Induced Damage Characterization of Porous Structural Silicon Oxide Film with Hexagonal Period by Nanoimprint Lithography

Abstract

We designed and fabricated a porous nanostructured film with a hexagonal period for a high-power laser system. The proposed nanostructure exhibits polarization-independent, infrared, and antireflective properties. The measured transmittance of the structural film does not drop below 93% between 948 nm and 2500 nm (exceeding 95% from 1411–2177 nm), and this performance is maintained for incident angles ranging from 0–30°. The laser-induced damage threshold (LIDT) of the structural film (17.94 J/cm2) is much higher than that of the single layer of SiO2 film (7.06 J/cm2). These results show that the preparation process is an effective technique to obtain a large-scale structural surface for high-power laser systems.