To study the OH-ion contamination mechanism in silica-based optical fiber waveguides, a method for measuring the OH-ion distribution profile in fiber-rod preforms has been developed. Using a low-OH-content optical fiber as a light probe of the measuring set, high spatial resolution of several tens of micrometers was obtained. Using this technique, the OH-ion distribution profiles in nondoped silica-rod preforms were measured optically at 2.73 µm. The OH-ion distribution profile observed closely agreed with the calculated diffusion profile, from which the diffusion coefficient of OH-ion in silica glass was estimated to be ~7.0 × 10-9 cm2 sec-1 at 1600°C.
© 1978 Optical Society of America
M. Horiguchi and M. Kawachi, "Measurement technique of OH-ion distribution profile in rod preform of silica-based optical fiber waveguides," Appl. Opt. 17, 2570-2574 (1978)