Abstract: A system, device, and method for laser cooling rare earth doped silica glass using anti-Stokes fluorescence is disclosed. The system includes a rare earth doped and codoped with one or more codopants silica glass; a laser that provides radiation to a first surface and through a body of the rare earth doped silica glass, wherein the laser is tuned from a first wavelength to a second wavelength; and a thermally sensitive device that captures images of the rare earth doped silica glass as the laser is tuned and determines a third wavelength between the first wavelength and the second wavelength where the rare earth doped silica glass is maximumly or near maximumly cooled.

Abstract: A system for measuring an absorption coefficient of a doped optical fiber may include: a laser source configured to transmit laser light at a selectable wavelength; a single-mode optical fiber including an end configured to splice to the doped optical fiber; two or more multimode fibers at a side of the doped optical fiber, spaced apart along the side of the doped optical fiber, configured to collect spontaneous emissions from the side of the doped optical fiber; and/or a photodiode or power meter connected to the two or more multimode fibers. A method for measuring an absorption coefficient of a doped optical fiber may include: collecting, from a side of the doped optical fiber, an emission spectrum using two or more multimode fibers; and/or calculating the absorption coefficient form using the emission spectrum and McCumber theory.

Abstract: A system for measuring an absorption coefficient of a doped optical fiber may include: a laser source configured to transmit laser light at a selectable wavelength; a single-mode optical fiber including an end configured to splice to the doped optical fiber; two or more multimode fibers at a side of the doped optical fiber, spaced apart along the side of the doped optical fiber, configured to collect spontaneous emissions from the side of the doped optical fiber; and/or a photodiode or power meter connected to the two or more multimode fibers. A method for measuring an absorption coefficient of a doped optical fiber may include: collecting, from a side of the doped optical fiber, an emission spectrum using two or more multimode fibers; and/or calculating the absorption coefficient form using the emission spectrum and McCumber theory.