Fig. 1. (a) Scheme of the 1053 nm laser source. PBS: polarization beam splitter; L: lens; NDF: neutral density filter; NOPA: noncollinear OPA. The linewidth indicates the beam size roughly and the shade indicates the pulse energy. (b) Schematic of the NOPA, where the angle between the signal and the pump is less than 0.7°.

Fig. 2. (a) Spectra of NOPA2 output. The orange area is the amplified signal pulse and the green area is the idler pulse of NOPA2. The orange dashed line (simulated signal) and green dotted line (simulated idler) are the simulated spectra. The red area of the inset is the spectrum of the white light generated by YAG, and the jitter before 500 nm (gray area) may be caused by stray light of the spectrometer. The blue line of the inset is the amplified signal pulse of NOPA1. (b) Spectra of second-harmonic generation of the idler from NOPA2. The spectra fluctuate in the red area, and the middle solid line is the average value.

Fig. 3. Pulse width of the output 1053 nm. (a) Measured FROG trace. (b) Retrieved FROG trace. (c) Retrieved spectral intensity (blue solid line), spectral phase (orange), and actual spectrum of 1053 nm (blue dashed line). (d) Retrieved temporal intensity (blue solid line), retrieved temporal phase (orange) and Fourier transform-limited pulse (blue dashed line). The grid sizes are 256 × 256.

Fig. 4. (a) Temporal contrast of the initial 1030 nm (red line) and output 1053 nm (black line) pulses. The blue box indicates the noise level. (b) Details of the temporal contrast of the initial 1030 nm (red line) and output 1053 nm laser pulses (black line) at ±40 ps time.

Fig. 5. The quality of the output 1053 nm beam. (a) The beam pointing stability. (b) The M² quality of the output laser beam. (c) The power stability.