title: Novel technique for the determination of hydroxyl distributions in fused silica.
abstract: Bound OH- is one major unwanted absorbing impurity causing significant attenuation for certain wavelengths of laser radiation when propagating through fused silica. A wavelength tunable laser calorimeter (LCA) is used to detect dopants and other impurities in optical material. Also, a technique for photothermal absorption measurements is combined with the LCA set-up allowing for a lateral scan of the sample retaining an absolute calibration. Regarding inhomogeneities within the distribution of impurities the combination of both techniques provides a highly sensitive method to investigate in the lateral distribution of OH- content in fused silica.
authors.affiliation: Laser Zentrum Hannover e.V., Department of Thin Film Technology, Hollerithallee 8, 30419 Hannover, Germany. l.jensen@lzh.de
authors.forename: Lars O
authors.initials: LO
authors.lastname: Jensen
authors.forename: Istvan
authors.initials: I
authors.lastname: Balasa
authors.forename: Holger
authors.initials: H
authors.lastname: Blaschke
authors.forename: Detlev
authors.initials: D
authors.lastname: Ristau