Fig. 1. Beam deflection principle of liquid crystal polarization grating

Fig. 2. Optical path principle of scanning system

Fig. 3. Scanning angle range of liquid crystal polarization grating

Fig. 4. Optimized optical path of system

Fig. 5. Evaluation results of optical system

Fig. 6. Working principle of control system

Fig. 7. Three-stage cascaded liquid crystal polarization gratings

Fig. 8. Flow chart of control program

Fig. 9. Optical layout for testing response characteristics of liquid crystal half-wave plate

Fig. 10. Response characteristics of liquid crystal half-wave plate

Fig. 11. Experimental optical path for measuring control voltage of liquid crystal half-wave plate

Fig. 12. Optical spot images of measuring control voltage of half-wave plate

Fig. 13. Experimental system for beam scanning

Fig. 14. Optical spots for different scanning positions of beam

Fig. 15. Diagram of relationship between scanning angles and errors

Fig. 16. Diagram of relationship between deflection times and scanning angles