Patent ID: 7292766

Claim:
An optical waveguide comprising: a substrate; and a glass doped with a rare earth dopant deposit on and affixed to a surface of the substrate, wherein the glass comprises: (a) Al 2 O 3 , at least one of rare earth oxide (REO) or Y 2 O 3 , and at least one of ZrO 2 or HfO 2 , wherein at least 80 percent by weight of the glass collectively comprises the Al 2 O 3 , at least one of REO or Y 2 O 3 , and at least one of ZrO 2 or HfO 2 , based on the total weight of the glass; or (b) Al 2 O 3 , at least one of REO or Y 2 O 3 , and at least one of ZrO 2 or HfO 2 , wherein at least 80 percent by weight of the glass collectively comprises the Al 2 O 3 , at least one of REO or Y 2 O 3 , and at least one of ZrO 2 or HfO 2 , and wherein the glass contains not more than 20 percent by weight SiO 2 and not more than 20 percent by weight B 2 O 3 , based on the total weight of the glass, wherein the rare earth dopant is a different material than REO and the rare earth dopant is selected from the group consisting of cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, or their other compounds and mixtures thereof.