Monocrystalline Yb³⁺:(Gd,Lu)₂O₃ channel waveguide laser at 976.8 nm

We report on a $Yb^{3+}$-doped sesquioxide waveguide laser based on a lattice-matched $Yb^{3+}$(3%)$:(Gd,Lu)_2O_3$ film that has been epitaxially grown on $Y_2O_3$ using pulsed laser deposition. Rib-channel waveguides have been structured by reactive ion etching. Laser emission at 976.8 nm was observed under pumping with a $Ti^{3+}:Al_2O_3$ laser at 905 nm. A laser threshold of 17 mW and a slope efficiency of 6.7% have been achieved with respect to input power. For an incident pump power of 200 mW, a maximum output power of 12 mW could be realized.