Nano-imprint lithography of broad-band and wide-angle antireflective structures for high-power lasers
Mehrnaz Modaresialam, Nicoletta Granchi, Marek Stehlík, Camille Petite, Sorin Delegeanu, Anthony Gourdin, Mohammed Bouabdellaoui, Francesca Intonti, Badre Kerzabi, David Grosso, Laurent Gallais, Marco Abbarchi
Abstract
We demonstrate efficient anti reflection coatings based on adiabatic index matching obtained via nano-imprint lithography. They exhibit high total transmission, achromaticity (99.5% < T < 99.8% from 390 to 900 nm and 99% < T < 99.5% from 800 to 1600 nm) and wide angular acceptance (T > 99% up to 50 degrees). Our devices show high laser-induced damage thresholds in the sub-picosecond (>5 J/cm 2 at 1030 nm, 500 fs), nanosecond (>150 J/cm 2 at 1064 nm, 12 ns and >100 J/cm 2 at 532 nm, 12 ns) regimes, and low absorption in the CW regime (<1.3 ppm at 1080 nm), close to those of the fused silica substrate.