Ultrafast direct written waveguide Bragg gratings utilizing a high pulse energy femtosecond oscillator

Direct written Waveguide Bragg gratings (WBGs) were fabricated in Borosilicate. We utilized a 5.1 MHz femtosecond oscillator exploiting heat accumulation and micro-structuring effects. By synchronizing a Pockels cell to the translation of the sample the pulse energy was modulated between the cumulative heating regime and the micro-damaging regime. We present and characterize WBGs fabricated in a single step at high process speeds.