Fluorophosphate glass is a class of optical glasses composed of metaphosphates and fluorides of various metals. It is a variant of phosphate glasses. Some fluorophosphate glasses are used as low dispersion glasses. Some show anomalous partial dispersion. One such glass is composed of Ba(PO3)2, Al(PO3)3, AlF3, and alkaline earth fluorides MgF2, CaF2, SrF2, and BaF2, with possible addition of titanium, sodium, potassium, and/or hydrogen. The components by wt.% are 0.5-3% Mg, 8-10% Ca, 12-20% Sr, 9-12% Ba, 7-9% Al, 5-9% P, 8-12% O, and 35-38% F.