The invention discloses a multi-channel vector holographic polarization multiplexing method based on a birefringent medium metasurface, and belongs to the technical field of micro-nano optics and holographic multiplexing application. The method comprises the following steps that: the metasurface for achieving the holographic polarization multiplexing is composed of nano column arrays with rectangular cross sections and different geometric dimensions and different azimuth angles; by changing the geometric size and azimuth angles of the nano column unit, the phase and polarization state of the emergent light beam are randomly regulated and controlled by the metasurface; holograms corresponding to different mutually independent original images are obtained by using a GS algorithm; according to the obtained holograms, the geometric size and azimuth angles of the nano column unit are determined by coding so as to generate a processing file of a corresponding medium metasurface structure; the metasurface of the transmission-type medium is processed by adopting a micro-nano processing process of electron beam etching; through the selection of the polarization states of the incident lightbeam and emergent light beam, the combination and multiplexing of seven different polarization images of twelve different polarization channels are achieved.
Multi-channel vector holographic polarization multiplexing method based on birefringent medium metasurface