Design/deposition process tradeoffs for high-performance optical coatings in the DUV spectral region

Laser damage properties of Al2O3/MgF2 antireflection coatings on large, curved substrates at 248 nm

“…Surface roughness plays a key role in achieving low absorption and a high laser damage threshold for coatings. Surface preparation of the substrates is more critical in achieving a high laser damage threshold for AR coatings [6] as compared to high reflectors. Consequently, a larger variation in LIDT values is typically seen for AR coatings.…”

193 nm laser induced spectral shift in HR coated mirrors

“…Dielectric fluorides are excellent optical coating materials for 193-nm application due to their high transparency and low absorption. 2,3 However, evaporated fluoride films do contain the defects mentioned above, and, if heated, thermally activated atomic and/or molecular diffusion may readily take place. This reasoning follows from the knowledge that vacancies and micropores are known to play a key role in fostering diffusion in solid state materials.…”