Fig. 1. Schematic diagram of the seed laser. $\text{PBS}_{1}$, $\text{PBS}_{2}$: polarization beam splitters; FR: Faraday rotator isolator; HWP: half-wave plate; VBG: volume Bragg grating; $\text{BS}_{1}{-}\text{BS}_{3}$: beam splitters; $\text{M}_{1}{-}\text{M}_{5}$: high-reflectivity mirrors.

Fig. 2. Schematic diagram of the amplifier and SHG construction. $\text{P}_{1}{-}\text{P}_{3}$: polarizers; FR: Faraday rotator isolator; $\text{HWP}_{1}{-}\text{HWP}_{5}$: half-wave plates; $\text{TFP}_{1}$, $\text{TFP}_{2}$: thin-film polarizers; QWP: quarter-wave plate; PC: Pockels cell; $\text{R}_{1}$, $\text{R}_{2}$: convex mirrors; $\text{M}_{1}{-}\text{M}_{7}$: high-reflectivity mirrors; $\text{MD}_{1}{-}\text{MD}_{5}$: Nd:YAG modules; $\text{AL}_{1}$, $\text{AL}_{2}$: aspheric lenses; $\text{L}_{1}{-}\text{L}_{7}$: lenses; $\text{V}_{1}{-}\text{V}_{3}$: vacuum tubes; $\text{QR}_{1}$, $\text{QR}_{2}$: $90^{\circ }$ quartz rotators; $\text{A}_{1}$, $\text{A}_{2}$: aluminum blocks; $\text{M}_{8}$, $\text{M}_{9}$: dichroic mirrors.

Fig. 3. Waveform of RA.

Fig. 4. Beam direction fluctuation.

Fig. 5. Intensity distributions of (a) input Gaussian beam ($\text{TEM}_{00}$ laser) and (b) laser after the shaping lens.

Fig. 6. Power fluctuation at 1064 and 532 nm.

Fig. 7. Spectral evolution of the system. The spectral widths of the seed, RA and oscillator power amplifier are 0.187, 0.112 and 0.142 nm, respectively.

Fig. 8. Dependence of the green power and second harmonic conversion efficiency on the incident fundamental power.

Fig. 9. Spectrum of the SHG.

Fig. 10. Beam quality of SHG.