Fig. 1. Schematic of laser 3D imaging under different illumination modes. (a) Collimated illumination; (b) focused illumination

Fig. 2. Schematic of pixel points layout under sub-pixel scanning

Fig. 3. Design of confocal sub-pixel scanning device. (a) Device schematic; (b) resolution target; (c) panda doll

Fig. 4. Resolution target depth maps under collimated beam illumination

Fig. 5. Echo intensity histograms at different positions and comparison result of intensity. (a) Histogram at initial position; (b) histogram after small displacement offset; (c) intensity comparison of collimated illumination and focused illumination

Fig. 6. Illumination depth diagrams of collimated beam and focused beam at 8 m

Fig. 7. Illumination depth maps of focused beam with different scanning steps at 10 m

Fig. 8. Intensity and depth maps of panda doll illuminated by focused beam at 8 m

Fig. 9. 3D reconstruction results of panda doll. (a) Picture of panda doll; (b) result of pixel by pixel scanning; (c) result of 1/4 sub-pixel scanning; (d) result of 1/8 sub-pixel scanning