Fig. 1. Schematic diagram of the picosecond PW laser beam target alignment system

Fig. 2. Program interface for real-time identification of spots and target positions

Fig. 3. Experimental setup for the picosecond PW laser beam target alignment system. (a) Surrogate laser; (b) beam target alignment system

Fig. 4. Experimental results of resolution verification of the picosecond PW laser beam target alignment system. (a)(b) Two imaging surfaces of plate beam splitter + spherical lens; (c) the center field of cube beam splitter + spherical lens; (d) the edge field of cube beam splitter + spherical lens; (e) the center field of cube beam splitter + aspherical lens; (f) the edge field of cube beam splitter + aspherical lens

Fig. 5. Beam target coupling experiment. (a)‒(c) Beam target coupling by the beam target alignment system; (d) actual beam target coupling results

Fig. 6. Simulation results by Zemax. (a) Wavefront of plate beam splitter; (b) wavefront of cube beam splitter; (c) simulation of plate beam splitter + spherical lens; (d) simulation of the center field of cube beam splitter + spherical lens; (e) simulation of the edge field of cube beam splitter + spherical lens; (f) simulation of the center field of cube beam splitter + aspherical lens; (g) simulation of the edge field of cube beam splitter + aspherical lens

Fig. 7. Optimized result by Zemax. (a) Lens structure; (b) modulation transfer function(MTF) curves; (c) simulation of center field-of-view with 2.5 μm line pair; (d) simulation of edge field-of-view with 2.5 μm line pair