Direct writing of optical waveguides in fused silica by the fundamental beam of an Yb:KGW femtosecond laser

We report the fabrication of an optical waveguide with a propagation loss below 1 dB/cm in fused silica using the fundamental beam of an Yb:KGW femtosecond laser. By selecting the pulse energy and pulse duration, we obtained a propagation loss comparable with that of a waveguide made using a Ti:Sapphire laser. We demonstrate that the nano-wrinkles and nano-pores, which dominate the losses, are not formed in the modified silica if the pulse energy is below 0.80 mu J and the pulses are shorter than 300 fs. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

This study demonstrates the fabrication of an optical waveguide with propagation loss below 1 dB/cm using an Yb:KGW femtosecond laser in fused silica. By controlling pulse energy and duration, the propagation loss achieved is comparable to that of a waveguide made using a Ti:Sapphire laser. It is also shown that nano-wrinkles and nano-pores, which cause losses, can be avoided in modified silica under certain conditions.