High efficiency and high beam quality Er:YSGG Mid-infrared continuous-wave laser

•An LD end-pumped Er:YSGG mid-infrared (MIR) continuous-wave (CW) laser with high efficiency and high beam quality was demonstrated.•A composite crystal YSGG/Er:YSGG/YSGG with a size of 3 × 3 × 14 (2 + 10 + 2) mm3 was employed.•The absorption coefficient and thermal problems of the composite Er:YSGG crystal was optimized based on adjusting the center wavelength of the LD pump source.•The maximum output power of 2.01 W was achieved, corresponding to slope efficiency of 28.89 %, and the beam quality M2 of the laser was 1.19.