The invention discloses a method for constructing a dynamic multifocal
superlens based on a medium and
graphene. The method includes the following steps that: (1) as for incident light of different wavelengths,
phase gradient distribution on a medium metasurface within an
infrared wavelength range of 0.7 micron to 500 microns is calculated according to positional relations between focuses and wavelengths; (2) different periodic structures are designed for each center
wavelength, specific phase values are determined according to the
phase gradient distribution and Pancharatnam-
Berry phases; (3)height-determined columnar structures are designed as the basic units of the medium metasurface, and then, a corresponding concrete realization structure and rotation direction are designed; and (4)according to a substrate part, multilayer
graphene is adopted to form a reflection type focusing lens, and the
Fermi level of the
graphene can be changed such the position of a focusing point can be dynamically adjusted. According to the method of the invention, the dynamic multifocal reflective lens is realized through the medium metasurface and the multilayer graphene structure. The method has the advantages of high-efficiency focusing function, ultra-
wideband performance, dynamic adjustment, easiness in integration and the like.