Specific features of the formation of optical waveguides in silicate glass at high energy and doze of electron irradiation

The formation of an optical waveguide in silicate glass that contains alkali-metal ions is experimentally studied under electron irradiation at an energy of 50 keV and a doze of 25–50 mC/cm$^2$. A gradient waveguide with a maximum variation in the refractive index of 0.01–0.04 is formed in the glass due to irradiation. It is demonstrated that a variation in the refractive index results from both field migration of alkalimetal ions to the region of negative space charge and structural modifications in the glass related to the destruction of glass structure by high-energy electrons.