Theoretical limits of low optic loss in multicomponent halide glass materials.

This paper discusses a method whereby the minimum attenuation alpha(min) and its associated vacuum wavelength lambda(min) can be estimated for any vitreous multicomponent halide and presents specific numerical predictions for glasses based on such network formers as BeF2, CdF2, AlF3, ZrF4, HfF4, ThF4, CdCl2, BiCl3, ThCl4 and Cdl2. If such multicomponent glasses can be prepared which are homogeneous on the scale of lambda (min), then the ultimate low attenuation (in the absence of impurities or defects) is of order 0.0015-0.002 dB/km. This limit can be approached in divalent-cationic fluoride materials as well as in several heavier-halide glasses.