Dual-wavelength eye-safe Nd:GYSGG/YVO4 intracavity Raman laser under in-band pumping

An acousto-optic (AO) Q-switched dual-wavelength laser operating at 1.5 µm eye-safe region is demonstrated via stimulated Raman scatting of a-cut YVO4-Nd:YVO4 crystal within an end-pumped dual-wavelength Nd:GYSGG laser cavity. The in-band pumping absorption peak and coefficient of the dual-wavelength laser crystal Nd:GYSGG are measured in order to carry out efficient pumping, thus overcoming the drawbacks of short thermal focal length of the crystal and scale up the eye-safe output. Under 23.2 W absorbed pump power, 2.11 W of simultaneous dual-wavelength outputs at 1497 and 1516 nm are obtained with a pulse repetition rate of 23 kHz and a corresponding conversion efficiency of 9.1%.