Laser-induced damage of 1 064 nm antireflection/532 nm high-reflection bichromatic coatings

1 064 nm antireflection/532 nm high-reflection bichromatic coatings with and without barrier layer were fabricated on the UBK7 substrate using electron beam evaporation technique. The optical property and laser-induced damage threshold(LIDT) of the coatings were investigated, respectively. Compared with the coatings without barrier layer, the 1 064 nm LIDT of the bichromatic coatings with SiO2 barrier layer is 49.6% higher. By analyzing the morphology and depth information of laser-induced damage spots, and the standing wave electric field distribution of the film stacks, the mechanisms of 1 064 nm and 532 nm laser-induced damages of the bichromatic coatings were discussed. The results show that SiO2 barrier layer strengthens the coatings-substrate interface, and ther