Influence of laser light on induced-absorption spectra of fiber waveguides made of pure quartz glass

A study was made of the influence of laser light on radiation color centers in glass fiber waveguides of the SiO₂–SiO₂:B₂O₃ type. The induced-absorption spectra were determined in the wavelength range 300–1900 nm for fibers subjected to γ-ray doses from 300 to 10⁴ rad at irradiation temperatures 77 and 300 K. Eight types of radiation color centers were identified and the induced-absorption spectra of the waveguides were almost entirely due to these color centers. The centers differed in respect of the stability when subjected to laser light and temperature variations. Infrared absorption appeared when the induced-absorption band at 340 nm was suppressed by λ = 337 nm laser light and then restored at room temperature.