Abstract

ThF4 is widely used as standard low index material in optical coatings on infrared optics at 2.0- 12.0μm wavelength regions. Since Th is radioactive and toxic, handling of this material in film production, e.g. running and maintenance of the vacuum chamber, requires special investments for protection of the operators, and for eliminating pollution of the environment. Therefore, the search for other, less problematic materials as substitutes has been the subject of some earlier studied[1,2].

© 1998 Optical Society of America