Exterior surface damage of calcium fluoride outcoupling mirrors for DUV lasers.

Damage of optical components due to laser irradiation reduces reliability and limits durability. Calcium fluoride (CaF(2)) is commonly used for deep UV laser optics because it shows a very low tendency of color center formation as, compared to other UV-X optical materials. Here, we report on the exterior damage of CaF(2) UV-X optics due to radiation with high pulse-energy densities (80 mJ/cm(2)) from an ArF laser.