Fig. 1. Structure of double-layer LC lens with alignment conversion layer

Fig. 2. Modulation of E_x polarized light（a）and E_y polarized light（b）by LC lens

Fig. 3. Equivalent circuit of modal LC lens

Fig. 4. Distribution curves of the voltage（a）and the phase（b）of LC layer

Fig. 5. Fabrication flow of double-layer LC lens

Fig. 6. Optical path of imaging

Fig. 7. （a）Fuzzy image of LC lens without driving voltage；（b）Clear image under 0° polarized light by suitable driving voltage；（c）Clear image under 90° polarized light by suitable driving voltage；（d）Clear image under natural light by suitable driving voltage.

Fig. 8. Normalized focused light intensity of LC lens

Fig. 9. Mach-Zehnder interference optical path

Fig. 10. Imaging，interference and phase distribution diagrams at different voltage，frequency，and object distance.（a）10.12 V_rms，150 kHz，13 cm；（b）15.1 V_rms，220 kHz，12 cm；（c）22.5 V_rms，300 kHz，11 cm；（d）28.8 V_rms，350 kHz，10.5 cm.

Fig. 11. Lens power of the LC lens as a function of an applied voltage