Fig. 1. Schematic diagram of the exposure

Fig. 2. Schematic diagram of the scanning motion. (a) Motion module; (b) beam expansion module; (c) scanning track

Fig. 3. Uniformity of light intensity. (a) Schematic diagram of multiple scan overlay; (b) uniformity of light intensity at different S/ω

Fig. 4. Experimental setup

Fig. 5. Flowchart of the procedure. (a) Processing of spot patterns; (b) fringe drift-locking

Fig. 6. Schematic diagrams of spot. (a) ω=5 mm; (b) ω=8 mm; (c) ω=15 mm

Fig. 7. Intensity distribution curves along the step direction. (a)-(c) ω=5 mm, S/ω is 1.1, 1.2, 1.3, respectively; (d)-(f) ω=8 mm, S/ω is 1.1, 1.2, 1.3, respectively; (g)-(i) ω=15 mm, S/ω is 1.1, 1.2, 1.3, respectively

Fig. 8. Comparative tests with open and closed loop. (a) Schematic diagram of fringe drift-locking at different positions; (b)(c) time domain analysis of the fringe drift at the reference light point; (d)-(f) time domain analysis of fringe drift at different positions; (g)-(i) frequency domain analysis of fringe drift at different positions

Fig. 9. Comparative test with open and closed loop. (a)(b)(c)(g)(h)(i) Time domain analysis of fringe drift at different positions; (d)(e)(f)(j)(k)(l) frequency domain analysis of fringe drift at different positions