Abstract: There is provided hollow microspheres comprising: at least 45 wt % of recycled glass based on the total weight of a feed composition from which the hollow microspheres are derived, wherein the hollow microspheres have a density of less than 1.25 g/cm3, strength at 20% volume reduction greater than 20 MPa and have a substantially single cell structure. There is also provided hollow microspheres comprising: a blend of recycled glass and glass feed, wherein the hollow microspheres have a density of less than 1.25 g/cm3 and are made from a feed composition that is essentially free of an added effective blowing agent. There is provided a method for making hollow microspheres.

Abstract: This invention relates to the use of novel glass materials comprising rare earth aluminate glasses (REA1™ glasses) in the gain medium of solid state laser devices that produce light at infrared wavelengths, typically in the range 1000 to 3000 nm and for infrared optics with transmission to approximately 5000 nm in thin sections. The novel glass materials provide stable hosts for trivalent ytterbium (Yb3+) ions and other optically active species or combinations of optically active species that exhibit fluorescence and that can be optically excited by the application of light. The glass gain medium can be configured as a waveguide or placed in an external laser cavity, or otherwise arranged to achieve gain in the laser waveband and so produce laser action.

Abstract: This invention relates to the use of novel glass materials comprising rare earth aluminate glasses (REA1™ glasses) in the gain medium of solid state laser devices that produce light at infrared wavelengths, typically in the range 1000 to 3000 nm and for infrared optics with transmission to approximately 5000 nm in thin sections. The novel glass materials provide stable hosts for trivalent ytterbium (Yb3+) ions and other optically active species or combinations of optically active species that exhibit fluorescence and that can be optically excited by the application of light. The glass gain medium can be configured as a waveguide or placed in an external laser cavity, or otherwise arranged to achieve gain in the laser waveband and so produce laser action.