Laser-Induced Damage of Anti-Reflection Coating for Optical Guide of YAG Laser

Abstract

Antireflection (AR) coating with high damage resistance for optical guides of high power YAG laser was developed. We have indicated that each single layer films must be improved AR coating with high damage threshold. An optimum deposition of the Si0₂ film and Ta₂O₅ films that compose the AR coating was studied by the Taguchi method. Reflectance and laser-induced damage threshold of AR coating was less than 0.2% and 15.9 J/cm², respectively at 1064 nm. The AR coating irradiated by cw YAG laser of 3-kW class was durable for 5 minutes.