High-dispersion optical glass - based on barium fluorophosphate and fluorides of aluminium, magnesium, calcium and strontium

摘要

Optical glass, which can replace the expensive CaF2 or BaF2 monocrystals in instruments in which a similar index of refraction but a higher dispersion degrees is required, consists of (in mole %): BaPO3F 8.0-29.9, AlF3 30-40, MgF2 4.76-10.0, CaF2 15-30, and SrF2 4.76-20. Opt 2-8 mole % YF3, 5-10 mole % MgO. and 5 mole % CaO can be added. These glasses have wide transparency range. Monochromatic aberration is greatly reduced; at higher BaPO3F contents (20.0-29.9 mole %) and in the presence of MgO, the spherical aberration is reduced.