Rayleigh Scattering in K_2O--MgO-SiO_2 and Na_2O-B_2O_3-SiO_2 Glasses

摘要

We investigated the Rayleigh scattering of ternary glass systems K_2O--MgO-SiO_2 and Na_2O-B_2O_3-SiO_2. The minimum Rayleigh scattering coefficients in both glasses were considerably lower than that in pure silica glass. The Rayleigh scattering due to concentration fluctuation of Na_2O-B_2O_3-SiO_2 glass increased rapidly with decreasing Na_2O content. By contrast, that of K_2O--MgO-SiO_2 glass was almost independent of the K_2O content. We found that K_2O--MgO-SiO_2 glasses with a high SiO_2 content (70 ～ 75 mol/100) can be expected as candidates for fabricating ultralow loss fiber because of their low Rayleigh scattering, zero material dispersion wavelength near 1.55 μm.