Published online by Cambridge University Press: 31 January 2011
Elemental migration inside a glass was induced space-selectively and microscopically by high-repetition femtosecond(fs) laser irradiation. The tendency of the elemental migration depended on the strength of the bond between cations and oxygen ions:strongly bonded ions like Si or Al migrated to the center of the irradiated spot, whereas weekly bonded ions such as Ca migrated to the outside. Judged from analyzed temperature distribution, this phenomenon may be due to the thermomigration(Soret effect). The refractive index distribution was modified locally by controlling elemental distribution and optical waveguide was formed in phosphate and borate glasses.