Yb/Al-codoped fused-silica planar-waveguide amplifier

•Yb/Al-codoped silica waveguides with 0.2 dB loss and 0.6 dB gain per 1 cm are reported.•Waveguides feature a large core (20 μm) and a high CW damage threshold (>0.1 GW/cm2).•Full Yb3+ functionality was determent by lifetime, gain and absorption measurements.

We report an Yb/Al-codoped fused silica planar waveguide amplifier with <0.2 dB/cm passive loss and 0.6 dB/cm gain, featuring a high damage threshold (>0.1 GW/cm2) and a relatively large core (20 μm thick). Waveguide fabrication is based on a novel silica-on-silica technology combining modified-chemical-vapor deposition and a high temperature CO2 laser treatment for making high-power photonic devices.