Enhanced high-slope-efficiency and high-power LD side-pumped Er:YSGG laser

We designed a high-slope-efficiency and high-power laser diode (LD) side-pump Er:YSGG laser based on the analysis for the effect of the crystal dimension and the LD distribution on the temperature and energy distributions in laser crystal. A maximum output power of 34.9 W for a 2.8 µm mid-infrared laser was achieved at 200A, 120 Hz, and 500 µs pulse width, corresponding to the slope efficiency of 13.7% and optical-optical efficiency of 12.7%. Moreover, the beam quality $M_x^2/M_y^2$Mx2/My2 factors of the laser were measured to be 5.15/5.19 and the far-field divergences ${\Theta _x}/{\Theta _y}$Θ_x/Θ_y were 9.52/9.75 mrad.