Room-temperature laser operation at 1.8 μm in Tm:GdVO4 waveguides

We report on the first experimentally demonstrated Tm-doped gadolinium vanadate waveguide laser operating at 1.8 mu m. Cladding waveguides with a diameter of 60 mu m are fabricated by femtosecond laser direct writing (FsLDW) in 3 at. % Tm:GdVO4 crystal. A continuous-wave (CW) Ti:sapphire laser is used as the pump source for waveguide laser generation. The impacts of waveguide lengths and cavity conditions on the obtained lasing performance are well studied. For the Tm:GdVO4 waveguide with a total length of 2.8 mm, the laser output at 1812 nm is achieved with a lasing threshold of 116.6 mW and a slope efficiency of 23.2% when utilizing the pi-polarized pump source at 799 nm. And the maximum output power of 179 mW is determined at a pump power of 932 mW, which corresponds to an overall optical-to-optical efficiency of 19.2%. The experimental results achieved in this work suggests that compact and low-threshold Tm:GdVO4 waveguide lasers can be very promising for applications in mid-infrared photonic devices with compact structures.