Fig. 1. Layout of the SG series laser facilities.

Fig. 2. Schematic of the SG-II 5PW laser facility. AO: adaptive optics; HS: Hartmann sensor; DM: deformable mirror; OAP: off-axis parabolic mirror; AWG: arbitrary waveform generator; FM: frequency modulator.

Fig. 3. Four-pass Öffner stretcher (left), laser based on Nd:YAG (middle) and first stage OPCPA on operation (right).

Fig. 4. Waveforms of the pump pulses for OPA-I and OPA-II.

Fig. 5. Waveforms of the chirped signal pulse along the current amplification chain.

Fig. 6. Signal pulse spectra for different amplification stages.

Fig. 7. (a) Normalized near-field distribution and (b) far-field focal spot of OPA-I.

Fig. 8. SG-II laser facility (left), a large-aperture KDP crystal (as a second harmonic generator (middle)), and a large-aperture LBO crystal in the second OPCPA stage (right).

Fig. 9. (a) Near-field distributions of the pump at location of LBO crystal and (b) signal pulse after the master compressor.

Fig. 10. Statistics of the pump and signal pulses energy as well as the pump-to-signal conversion efficiency for all shots of the OPA-II.

Fig. 11. (a) Amplified signal energy fluctuation for various pumps, (b) conversion efficiency, and (c) FF (red line) and FBC (blue line) along the LBO length in the OPCPA-II; the dotted lines in (c) are borderlines of the four intervals.

Fig. 12. FF (red line) and FBC (blue line) for the OPCPA-II amplified signal as a function of the crystal length that correspond to the amplification (a) with the ideal spatial–temporal super-Gaussian pump pulse and actual signal pulse and (b) that with the ideal spatial–temporal super-Gaussian signal pulse and actual pump pulse, respectively.

Fig. 13. Compressor tank (left) and an inner image of the gold-coated gratings (right).

Fig. 14. Compressed pulse duration with the whole beam diameter.

Fig. 15. Profile measured by a third-order cross-correlator with the whole beam diameter.

Fig. 16. Deformable mirror (left) and Hartmann sensor (right) in AO system.

Fig. 17. The measured static aberrations (a) before and (b) after correction, and (c) the pre-compensated dynamic aberrations when the amplifiers are on operation at the master compressor entrance; (d), (e) and (f) the calculated encircled energy and the profiles of far-field focal spot, respectively, corresponding to (a), (b) and (c).

Fig. 18. Target chamber.

Fig. 19. After the AO correction, (a) the focal spot of the unamplified signal pulse imaged by a CCD and (b) that of the high energy pulse imaged by an X-ray pinhole camera.

Fig. 20. (a) 3D ray tracing of OAP; focal spot size increase (b) as a function of the angular deviation of the incident light and (c) as a function of the deviation from the focal plane.