Abstract: A thulium doped silicate glass composition which contains SiO2, Al2O3, and La2O3 emits visible and UV light when excited by infrared light. The glass composition may also contain GeO2 and Er2O3. When excited by infrared light of about 1060 nm, the glass emits visible light at fluorescent transitions of the Tm3+ ions with major broad features at 365, 455, 472, 651, and 791 nm.

Abstract: A wavelength tunable optical device comprises a polarization maintaining (PM) optical fiber having a length, a first end, a second end, and an initial birefringence. The PM optical fiber receives polarized light from a first polarizer adjacent to the first end of the PM optical fiber. A second polarizer receives a light output from the second end of the PM optical fiber. A wavelength tunable optical device provides a plurality of spectral peaks leaving the second polarizer with a periodicity determined by the length of the PM optical fiber. Each of the plurality of spectral peaks has a wavelength dependent upon the length and the initial birefringence of the PM optical fiber. The PM optical fiber is a radiation tunable optical fiber adaptable to a tuned birefringence such that the periodicity and each of the wavelengths change to a selectively tuned wavelength and a tuned periodicity.

Abstract: A radiation tuned optical fiber comprises an optical fiber that includes a substantially circular core and a cladding containing an asymmetric stress zone. The substantially circular core has an initial birefringence. A length of the optical fiber has at least one radiation-tuned portion wherein the substantially circular core has a tuned birefringence to provide the radiation tuned optical fiber in which the tuned birefringence differs from the initial birefringence.

Abstract: In one aspect, the invention provides glass beads and optical devices comprising the glass beads. In other aspects, the invention provides methods of making said glass beads and rapid glass screening methods that use glass beads. Glass beads of the invention comprise greater than 80 weight percent silica, active rare earth dopant, and modifying dopant. In another embodiment the glass beads comprise greater than 80 weight percent silica and at least 5 weight percent germania. In another embodiment, glass beads comprise and from about 20 to about 90 anion mole percent of non-oxide anion.

Abstract: A co-doped silicate optical waveguide having a core including silica, and oxides of aluminum, germanium, erbium and thulium. The composition concentrations are: Er from 15 ppm to 3000 ppm; Al from 0.5 mol % to 12 mol %; Tm from 15 ppm to 10000 ppm; and Ge from 1 mol % to 20 mol %. In a specific embodiment, the concentration of Er is from 150 ppm to 1500 ppm; Al is from 2 mol % to 8 mol %; and Tm is from 15 ppm to 3000 ppm. A boron-less cladding surrounds the core.

Abstract: A fusion splice including a first optical fiber having a first MFD and a first MFD expansion rate. The splice further includes a second fiber having a second MFD and a second MFD expansion rate, wherein the second MFD is lower than the first MFD. The second fiber comprises a core, a cladding radially surrounding the core, and a zone of high-concentration of fluorine between the core and the cladding. The rate of MFD expansion of the first fiber is less than the rate of MFD expansion of the second fiber during the fusion splicing operation.

Abstract: An optical waveguide including a core having silica, Al, a non-fluorescent rare-earth ion, Ge, Er, and Tm. The non-fluorescent rare-earth ion may be La. Exemplary compositions concentrations are Er is from 15 ppm to 3000 ppm, Al is from 0.5 mol % to 12 mol %, La is less than or equal to 2 mol %, Tm is from 15 ppm to 10,000 ppm; and the Ge is less than or equal to 15 mol %. The core may further include F. An exemplary concentration of F is less than or equal to 6 anion mol %.

Abstract: A thulium doped silicate glass composition which contains SiO2, Al2O3, and La2O3 emits visible and UV light when excited by infrared light. The glass composition may also contain GeO2 and Er2O3. When excited by infrared light of about 1060 nm, the glass emits visible light at fluorescent transitions of the Tm3+ ions with major broad features at 365, 455, 472, 651, and 791 nm.

Abstract: An optical article including a core; at least one cladding layer; and a narrow fluorine reservoir between the core and the cladding layer. The fluorine reservoir has a higher concentration of fluorine than either the cladding layer or the core. One particular embodiment includes a core including a halide-doped silicate glass that comprises approximately the following in cation-plus-halide mole percent 0.25-5 mol % Al2O3, 0.05-1.5 mol % La2O3, 0.0005-0.75 mol % Er2O3, 0.5-6 mol % F, 0-1 mol % Cl.

Abstract: A method of making an erbium-doped optical fiber for use in optical amplifiers according to the present invention includes the step of providing a substrate tube. High purity silica-based cladding layers are deposited on the inside of the tube. A core glass that includes silica, Al, a non-fluorescent rare-earth ion, Ge, Er, and Tm is then deposited in the tube. The non-fluorescent rare-earth ion may be La and the core may further include F. The tube is then collapsed to form a preform. Finally, the preform is drawn to yield optical fiber.

Abstract: An optical waveguide including a core having silica, Al, a non-fluorescent rare-earth ion, Ge, Er, and Tm. The non-fluorescent rare-earth ion may be La. Exemplary compositions concentrations are Er is from 15 ppm to 3000 ppm, Al is from 0.5 mol % to 12 mol %, La is less than or equal to 2 mol %, Tm is from 15 ppm to 10,000 ppm; and the Ge is less than or equal to 15 mol %. The core may further include F. An exemplary concentration of F is less than or equal to 6 anion mol %.

Abstract: A germanium-free co-doped silicate optical waveguide in accordance with the present invention includes a core material comprising silica, and oxides of aluminum, lanthanum, erbium and thulium, wherein the concentration of Er is from 15 ppm to 3000 ppm; Al is from 0.5 mol % to 15 mol %; La is less than 2 mol %; and Tm is from 150 ppm to 10000 ppm. In an exemplary specific embodiment the concentration of Al is from 4 mol % to 10 mol %; and the concentration of Tm is from 150 ppm to 3000 ppm. The core may further include F. In an exemplary embodiment, the concentration of F is less than or equal to 6 mol %. The waveguide may be an optical fiber, a shaped fiber or other light-guiding waveguides. An amplifier according to the present invention includes the optical fiber described above.

Abstract: A method for manufacturing an optical fiber, the method including the steps of providing a substrate tube; depositing a boron-free cladding layer; depositing a core comprising a glass including silica, and oxides of Al, Ge, Er, and Tm; collapsing the substrate tube to form a preform; and drawing the preform to yield optical fiber.

Abstract: A co-doped silicate optical waveguide having a core including silica, and oxides of aluminum, germanium, erbium and thulium. The composition concentrations are: Er from 15 ppm to 3000 ppm; Al from 0.5 mol % to 12 mol %; Tm from 15 ppm to 10000 ppm; and Ge from 1 mol % to 20 mol %. In a specific embodiment, the concentration of Er is from 150 ppm to 1500 ppm; Al is from 2 mol % to 8 mol %; and Tm is from 15 ppm to 3000 ppm. A boron-less cladding surrounds the core.

Abstract: A method for manufacturing an optical fiber, the method including the steps of: providing a substrate tube; depositing high purity silica-based cladding layers on the inside of the tube; depositing a germanium-free core comprising a glass including silica, and oxides of Al, La, Er, and Tm; collapsing the substrate tube to form a preform; and drawing the preform to yield an optical fiber.

Abstract: In one aspect, the invention provides glass beads and optical devices comprising the glass beads. In other aspects, the invention provides methods of making said glass beads and rapid glass screening methods that use glass beads. Glass beads of the invention comprise greater than 80 weight percent silica, active rare earth dopant, and modifying dopant. In another embodiment the glass beads comprise greater than 80 weight percent silica and at least 5 weight percent germania. In another embodiment, glass beads comprise and from about 20 to about 90 anion mole percent of non-oxide anion.

Abstract: A fusion splice including a first optical fiber having a first MFD and a first MFD expansion rate. The splice further includes a second fiber having a second MFD and a second MFD expansion rate, wherein the second MFD is lower than the first MFD. The second fiber comprises a core, a cladding radially surrounding the core, and a zone of high-concentration of fluorine between the core and the cladding. The rate of MFD expansion of the first fiber is less than the rate of MFD expansion of the second fiber during the fusion splicing operation.

Abstract: An optical article including a core; at least one cladding layer; and a narrow fluorine reservoir between the core and the cladding layer. The fluorine reservoir has a higher concentration of fluorine than either the cladding layer or the core. One particular embodiment includes a core including a halide-doped silicate glass that comprises approximately the following in cation-plus-halide mole percent 0.25-5 mol % Al2O3, 0.05-1.5 mol % La2O3, 0.0005-0.75 mol % Er2O3, 0.5-6 mol % F, 0-1 mol % Cl.

Abstract: A method for manufacturing an optical article including the steps of providing a substrate tube; forming one or more cladding layers inside the substrate tube, the one or more cladding layers including an innermost cladding layer; forming a concentric fluorine reservoir adjacent to the innermost cladding layer; and forming a core adjacent to the fluorine reservoir and concentric with the one or more outer cladding layers. The fluorine concentration in the fluorine reservoir is higher than the fluorine concentration in either the core or the innermost cladding layer.

Abstract: Silica tubes and sleeves are used to protect fusion splices between the ends of the fiber coil and polarizing fibers. Use of silica for most of the subassembly components matches the coefficients of thermal expansion of the subassembly to that of the fiber coil, and also allows the coil to be annealed at extremely high temperatures. Annealing yields fiber coils of lowered birefringence, particularly when used with spun fibers. Ferrules are used to adjust the angular orientation of the fibers with respect to their planes of polarization.