Intrinsic birefringence in calcium fluoride and barium fluoride

John Burnett, Zachary Levine, Eric Shirley
2001 Physical Review B (Condensed Matter)  
We report measurements of the intrinsic birefringence in CaF 2 and BaF 2 for wavelengths in the range 365 nm to 156 nm, and ab initio optical response calculations in these materials and Si, Ge, GaAs, and GaP. Calculations typically agree within 40%. For ͗110͘ propagation, where the effect is largest, our measurements for CaF 2 ͓BaF 2 ͔ give n ͗1 10͘ Ϫn ͗001͘ ϭ(Ϫ11.8Ϯ0.4)ϫ10 Ϫ7 ͓(ϩ34Ϯ3)ϫ10 Ϫ7 ͔ for ϭ156.10 nm. The magnitudes of these values have serious consequences for the use of crystalline
more » ... se of crystalline optics in precision optical systems in the ultraviolet, including 193 nm and 157 nm optical lithography.
doi:10.1103/physrevb.64.241102 fatcat:avgszg7srrgxxajx3nrdwqxmjm