Continuous wave laser operation in Nd:GGG depressed tubular cladding waveguides produced by inscription of femtosecond laser pulses

Abstract

Depressed tubular cladding waveguides have been produced in Nd:GGG crystals by using multiple inscription with femtosecond (fs) laser pulses. The guiding cores are located inside the tubular regions with crosssection diameters of 90-150 μm, which are surrounded by fs-laser induced low-refractive-index tracks. At room temperature continuous wave (cw) laser oscillations at wavelength of ~1063 nm have been realized through the optical pump at 808 nm. The slope efficiency of the cladding waveguide lasers is as high as 44.4% and the maximum output power at 1063 nm is 209 mW, which shows superior laser performance to the Type II stress induced Nd:GGG waveguides.