Abstract: The present disclosure relates to a silica-based crucible material that includes, before sintering or firing, selected amounts of a thermal expansion stabilizer component (B2O3 and Ca2SiO4) which impart improved thermal shock resistance and enhanced ability to withstand repeated thermal cycling, to a sintered or fired crucible made of the material. An illustrative embodiment of the invention provides a crucible material whose chemical composition comprises, in weight %, about 91% to about 98% SiO2, about 1% to about 8% thermal stabilizer component, and up to about 1.0% of additional oxides including MgO, Al2O3 Fe2O3, CaO and ZrO2.

Abstract: The present invention is directed to a fluorinated rare earth doped glass composition and method for making a glass-ceramic optical article therefrom, e.g. optical fiber waveguides, fiber lasers and active fiber amplifiers, having application in the 1300 nm and 1550 nm telecommunications windows. The inventive compositions include Pr3+ and/or Dy3+ in a concentration range of between 300-2,000 ppmw and Ag+ in a concentration range of between 500-2000 ppmw; or Er3+ in a concentration range of between 500-5,000 ppmw and Ag+ in a concentration range of between 0-2,000 ppmw. The monovalent silver ion provides an ionic charge balanced glass-ceramic crystal. These compositions exhibit reduced or absent rare earth ion clustering and fluorescence quenching effects in the presence of high concentrations of rare earth ion dopants.

Abstract: The present invention is directed to a fluorinated rare earth doped glass composition and method for making a glass-ceramic optical article therefrom, e.g. optical fiber waveguides, fiber lasers and active fiber amplifiers, having application in the 1300 nm and 1550 nm telecommunications windows. The inventive compositions include Pr3+ and/or Dy3+ in a concentration range of between 300-2,000 ppmw and Ag+ in a concentration range of between 500-2,000 ppmw; or Er3+ in a concentration range of between 500-5,000 ppmw and Ag+ in a concentration range of between 0-2,000 ppmw. The monovalent silver ion provides an ionic charge balanced glass-ceramic crystal. These compositions exhibit reduced or absent rare earth ion clustering and fluorescence quenching effects in the presence of high concentrations of rare earth ion dopants.