Wide-angle Moiré metalens with continuous zooming

Due to the high design freedom, metasurfaces are widely applied to realize miniaturized optical devices with high performance. Recently, assisted by optical design, monochromatic aberration–corrected lenses, composed of two metasurface layers, have been proposed for a well-focused light spot in the focal plane at large incident angles. However, the focus cannot be tuned in these structures. In this paper, based on the principle of the Moiré lens, a wide-angle (±30^◦) metalens with continuously tunable and monochromatic aberration–corrected focus that consists of two cascaded face-to-face metasurfaces is proposed. The focal length of the lens can be tuned by the mutual rotation of the metasurfaces. Simulation results show that the focal plane is changed to 5.34 µm when the rotation angle is increased by 0.4 rad at the incident wavelength of 810 nm. It is anticipated that the proposed metalens may have a good application prospect in integrated miniaturized imaging systems.