title: Nonlinear transmission and color-center dynamics in germanosilicate fibers at 420-540 nm.
abstract: We report evidence in support of the view that induced loss and nonlinear transmission in pure germanosilicate fibers at blue-green wavelengths are governed by the formation (through two-photon absorption), spontaneous and stimulated transformation, and bleaching (through single-photon events) of Ge(1), Ge(2), and Ge(3) color centers. Using a tunable pulsed-dye laser, the excitation spectrum of the induced absorption, its spectral attenuation, and the effects of Ge concentration and thermal annealing are investigated.
authors.forename: L J
authors.initials: LJ
authors.lastname: Poyntz-Wright
authors.forename: M E
authors.initials: ME
authors.lastname: Fermann
authors.forename: P S
authors.initials: PS
authors.lastname: Russell