Asymmetric Full-Color Vectorial Meta-holograms Empowered by Pairs of Exceptional Points

Abstract

Holography holds tremendous promise in applications such as immersive virtual reality and optical communications. With the emergence of optical metasurfaces, planar optical components that have the remarkable ability to precisely manipulate the amplitude, phase, and polarization of light on the subwavelength scale have expanded the potential applications of holography. However, the realization of metasurface-based fullcolor vectorial holography remains particularly challenging. Here, we report a general approach utilizing a modified Gerchberg−Saxton algorithm to achieve spatially aligned full-color display and incorporating wavelength information with an image compensation strategy. We combine the Pancharatnam−Berry phase and pairs of exceptional points to address the issue of redundant twin images that generally appear for the two orthogonal circular polarizations and to enable full polarization control of the vectorial field. Our results enable the realization of an asymmetric full-color vectorial meta-hologram, paving the way for the development of full-color display, complex beam generation, and secure data storage applications.

Twins of Exceptional Points with Opposite Chirality for Non-Hermitian Metasurfaces

“…In practical applications, most researches in non-Hermitian metasurfaces have been limited to achieving a single EP with a definite chirality, − which is around the scattering resonance of the meta-structures. To seek more than one EP with opposite chirality in non-Hermitian metasurfaces is significant; that two or more EPs are found can increase the degree of freedom in designing optical elements and exploring new functionalities …”