70% slope efficiency from an ultrafast laser-written Nd:GdVO4 channel waveguide laser.

We report high efficiency continuous wave laser oscillations at 1063.6 nm from an ultrafast laser written Nd(3+):GdVO4 channel waveguide under the 808 nm optical excitation. A record 17 mm·s(-1) writing speed was used while the low propagation loss of the waveguide (~0.5 dB·cm(-1)) enabled laser performance with a threshold pump power as low as 52 mW and a near to quantum defect limited laser slope efficiency of 70%.