Patent ID: 7531473

Claim:
A ytterbium-phosphate glass comprising: a base glass comprising 60 to 75 mole percent P 2 O 5 , 13 to 30 mole percent Yb 2 O 3 ; and from 0 to 30 mole percent of a combination of two or more of the following X 2 O 3 , R 2 O, and MO wherein; X 2 O 3 is present in an amount of from 0 to 26 mole percent and X is selected from the group consisting of Al, B, La, Sc, Y, and mixtures thereof; R 2 O is present in an amount of from 0 to 26 mole percent and R is selected from the group consisting of Li, Na, K, and mixtures thereof; and MO is present in an amount of from 0 to 26 mole percent and M is selected from the group consisting of Mg, Ca, Sr, Ba, Zn, and mixtures thereof; said ytterbium-phosphate glass further comprising at least one lasing ion selected from the group consisting of erbium oxide, neodymium oxide, holmium oxide, thulium oxide, or a mixture thereof.