Phys.org  May 30, 2024 Researchers in China demonstrated a 978 nm laser diode (LD) side-pumped YSGG/Er:YSGG/YSGG composite crystal with a size of Ф 3 mm × 65 mm and continuous-wave (CW) mode. By optimizing resonator length and output mirror transmittance, a maximum output power of 28.02 W was generated, corresponding to slope efficiency of 17.55% and optical-optical efficiency of 12.29%, respectively. The thermal focal lengths were obtained by resonator stability condition. The laser wavelength was centered near 2.8 µm. Moreover, the beam quality factors 2/2 were fitted to be 8.14 and 7.35, respectively. The results indicated that a high-performance 2.8 µm CW laser could […]