WRITING WAVE-GUIDES AND GRATINGS IN SILICA AND RELATED MATERIALS BY AFEMTOSECOND LASER

With the goal of creating various optical glass devices for the teleco mmunications industry, the effects of 810 nm, femtosecond laser radiat ion on various glasses were investigated. By focusing the laser beam v ia a microscope objective, transparent but visible, round-elliptical d amage lines were successfully written inside high silica, berate, soda -lime-silicate, fluoride and chalcogenide glasses. Microscopic ellipso metric measurements of the damaged region in pure and Ge-doped silica glasses showed refractive index increases of 0.01 to 0.035. The format ion of several types of defects, including Si E' or Ge E' centers, non -bridging oxygen hole centers, and peroxy radicals, was also detected in addition to the identification. These results suggest that multi-ph oton interactions occurs in the glasses and that it is possible to wri te three-dimensional optical circuits in bulk glasses via such a focus ed laser beam technique. (C) 1998 Elsevier Science B.V. All rights res erved.