Fig. 1. Structure of liquid crystal (LC) lens with a shiftable optical axis. (a) Schematic diagram of lens structure; (b) top view of lens structure; (c) electrode structure on upper substrate; (d) electrode structure on lower substrate

Fig. 2. Voltage difference distributions of positive lens. (a) x_c=-0.5 mm; (b) x_c=-0.25 mm; (c) x_c=0 mm; (d) x_c=0.25 mm; (e) x_c=0.5 mm

Fig. 3. Voltage difference distributions of negative lens. (a) x_c=-0.5 mm; (b) x_c=-0.25 mm; (c) x_c=0 mm; (d) x_c=0.25 mm; (e) x_c=0.5 mm

Fig. 4. Electrode structure fabricated by photolithography. (a) Partial electrode structure on upper substrate; (b) zoomed-in view of electrode structure on upper substrate; (c) partial electrode structure on lower substrate; (d) zoomed-in view of electrode structure on lower substrate

Fig. 5. Physical image of liquid crystal lens

Fig. 6. Polarized interferometry setup

Fig. 7. Interference fringes of positive and negative lenses. (a) Positive lens, x_c=-0.5 mm; (b) positive lens, x_c=-0.25 mm; (c) positive lens, x_c=0 mm; (d) positive lens, x_c=0.25 mm; (e) positive lens, x_c=0.5 mm; (f) negative lens, x_c=-0.5 mm; (g) negative lens, x_c=-0.25 mm; (h) negative lens, x_c=0 mm; (i) negative lens, x_c=0.25 mm; (j) negative lens, x_c=0.5 mm

Fig. 8. Setup for collecting focused light spot

Fig. 9. Focused spots of positive lens. (a) x_c=-0.5 mm; (b) x_c=-0.25 mm; (c) x_c=0 mm; (d) x_c=0.25 mm; (e) x_c=0.5 mm

Fig. 10. Intensity distributions of different focused spots. (a) Three-dimensional intensity; (b) cross-section intensity

Fig. 11. Recorded images when LC lens was turned off and on. (a) Lens was turned off; (b) lens was turned on

Fig. 12. Images recorded at different positions of lens optical axis