Efficient waveguide lasers in femtosecond laser inscribed double-cladding waveguides of Yb:YAG ceramics

We report on the fabrication of depressed double-cladding waveguides in Yb:YAG ceramics by using femtosecond (fs) laser inscription. The double-cladding structures consist of tubular central structures with 30 μm diameter and concentric larger size tubular claddings with diameters of 100-200 μm. Continuous wave laser oscillations at wavelength of 1030 nm have been realized at room temperature through optical pump at 946 nm. The obtained maximum output power of the double-cladding waveguide lasers is ~80.2 mW with a slope efficiency as high as 62.9%