Femtosecond laser direct-writing of waveguide Bragg gratings in a quasi cumulative heating regime.

Waveguide Bragg gratings (WBGs) were directly inscribed into Alkaline Earth Boro-Aluminosilicate glass samples in a single process step at high fabrication speeds. We utilized a 5.1 MHz femtosecond oscillator to exploit high repetition rate heat accumulation effects.