title: Brillouin spectroscopy of a novel baria-doped silica glass optical fiber.
abstract: Presented here for the first time to the best of our knowledge is a detailed Brillouin spectroscopic study of novel, highly-BaO-doped silica glass optical fibers. The fibers were fabricated utilizing a molten-core method and exhibited baria (BaO) concentrations up to 18.4 mole %. Physical characteristics such as mass density, acoustic velocity, visco-elastic damping, and refractive index are determined for the baria component of the bariosilicate system. It is found that, of each of these parameters, only the acoustic velocity is less than that of pure silica. The effect of temperature and strain on the acoustic velocity also is determined by utilizing estimates of the strain- and thermo-optic coefficients. The dependencies are found to have signs opposite to those of silica, thus suggesting both Brillouin-frequency a-thermal and a-tensic binary compositions. Via the estimate of the strain-optic coefficient and data found in the literature, the Pockels' photoelastic constant p(12) is estimated, and both a calculation and measured estimate of the Brillouin gain versus baria content are presented. Such novel fibers incorporating the unique properties of baria could be of great utility for narrow linewidth fiber lasers, high power passive components (such as couplers and combiners), and Brillouin-based sensor systems.
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 USA. p-dragic@illinois.edu
authors.forename: P
authors.initials: P
authors.lastname: Dragic
authors.forename: C
authors.initials: C
authors.lastname: Kucera
authors.forename: J
authors.initials: J
authors.lastname: Furtick
authors.forename: J
authors.initials: J
authors.lastname: Guerrier
authors.forename: T
authors.initials: T
authors.lastname: Hawkins
authors.forename: J
authors.initials: J
authors.lastname: Ballato
mesh_terms: D001464:Barium / Q000737:chemistry*; D055119:Elastic Modulus; D005898:Glass / Q000737:chemistry*; D008422:Materials Testing; D055100:Optical Fibers; D012031:Refractometry / Q000379:methods*; D012822:Silicon Dioxide / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D001464:Barium; D012822:Silicon Dioxide