Designed for the most demanding deep UV applications, our high-energy Excimer laser mirrors have an all dielectric coating designed to minimize scatter and maximize reflected energy. Excimer grade UV fused silica substrates polished to λ/10 flatness and 10-5 surface quality preserve wavefront quality, minimize scatter, and maintain stability.
Photo-contamination is a key word for Deep-UV optics, and Newport understands these requirements. We understand the effect contamination can have on Deep-UV optics, and we have invested years of research and analysis to develop materials and processes compatible to Deep-UV wavelengths. Great care is taken to make sure that incompatible materials are not introducted into the manufacturing process, and we take even greater care with our cleaning and coating processes. Special Pet-G and non-outgassing, metallicized lined packaging insure that parts are delivered clean and protected from any environmental photo-contamination.
Extensive analysis, research and testing have been done to better understand the conditions at these short UV wavelengths. The standard rules for coating design and processing do not always apply. Our coating scientists have investigated various conditions including thermal issues, densification of materials, and wavelength shift in order to properly optimize the performance of the mirrors at 193 nm under long term use.
An investigation is made of the spectral shift in 193 nm high reflection mirrors. Observations show that when the 193 nm mirror is irradiated, there is a spectral shift to shorter wavelengths which is due to densification of the coating structure.
A novel technique was employed to test the absorption of high reflectors during irradiation by a 193 nm ARF excimer laser source. Wavefront deformation was measured and shown that wavefront differences are caused by the compaction of the coating heated by the ARF source.