Fig. 1. Schematic diagram of the Er:LuAG SLM oscillator and the MOPA system. FR, Faraday rotator; F-P, Fabry-Perot etalon.

Fig. 2. Absorption cross section of the Er:LuAG crystal and the wavelength of the pump laser. Inset: the absorptivity of the Er:LuAG crystal under different pump powers.

Fig. 3. (a) Value of (A + D)/2 versus the thermal focal length of the Er:LuAG crystal. (b) Oscillating spot in the double CCRs Er:LuAG oscillator under different thermal focal lengths.

Fig. 4. Output power of the Er:LuAG oscillator without the Faraday rotator. Inset: Fabry–Perot spectrum.

Fig. 5. Output characteristics of the Er:LuAG SLM oscillator. (a) The output power. (b) The output wavelength and the Fabry-Perot spectrum.

Fig. 6. Influence of the CCR on the Er:LuAG SLM power. (a) Perpendicular to the CCR direction. (b) Parallel to the CCR line. (c) Rotating along the point on the axis.

Fig. 7. The gain and the amplified power versus the seed power.

Fig. 8. Laser properties of the Er:LuAG single-pass amplifier. (a) Beam qualities M² of the 2.32 W SLM laser. (b) The power stability within 30 minutes.