Patent ID: 8346029

Claim:
A multicomponent silicate glass fiber comprising: a core having a first doping concentration of 55%-85% (wt./wt.) of a first rare-earth oxide; and a cladding having a second doping concentration of 55%-85% (wt./wt.) of a second rare-earth oxide; wherein: the first rare-earth oxide and the second rare-earth oxide are selected from the group consisting of Pr 2 O 3 , Nd 2 O 3 , Pm 2 O 3 , Sm 2 O 3 , Eu 2 O 3 , Gd 2 O 3 , Tb 2 O 3 , Dy 2 O 3 , Ho 2 O 3 , Er 2 O 3 , Tm 2 O 3 , Yb 2 O 3 , La 2 O 3 , Ga 2 O 3 , Ce 2 O 3 , and Lu 2 O 3 ; and a refractive index of the cladding is lower than a refractive index of the core.