Bifocal Metalens with Diverse Polarization Combination

One compound metalens with the multiple functions is benefit to the optical integration. A bifocal metalens with diverse polarization combination is proposed by using the optical metasurface. This metalens consists of nanometer rectangular holes etched on a silver film. Two focusing spots result respectively from the propagation phase introduced by nanoholes with different sizes and the geometric phase caused by the rotation of nanoholes. Two focal spots for one designed compound metalens take on different polarization combination under different polarization light illumination. The interference between them is effectively controlled through the ingenious design. Theoretic analysis and calculation simulations give the powerful verification for the diverse polarization combination of the bifocal matelens. This focusing metalens with diverse polarization combination can expand the wide applications of metalenses.