High-threshold fluoride AR coatings for KDP crystal at 352 nm

The laser damage thresholds and other properties of 352 nm fluoride AR coatings for KDP substrate were investigated. The HoF3 (or LaF3)/AlF3 AR coating deposited by IAD process had a high threshold of 24 J/cm2 (10 ns) when the laser conditioning procedure was used. These fluoride ARs were durable for wiping and also did not degrade during more than one year under room atmosphere.