Researchers at the University of Birmingham have developed a metasurface hologram with 80% diffraction efficiency at 825 nm and a broad bandwidth between 630 nm and 1050 nm. The hologram uses a geometric metasurface (GEMS) design, which consists of an array of plasmonic nanorods with spatially varying orientations. This design allows for superior phase control and high polarization conversion efficiency. The GEMS hologram incorporates a ground metal plane to enhance the conversion efficiency between the two circular polarization states, leading to high diffraction efficiency without complicating the fabrication process. The study addresses the limitations of traditional phase-only computer-generated holograms (CGHs), which suffer from low efficiency and twin-image generation. The proposed GEMS design uses a 16-level phase CGH, combining the concept of GEMS for phase control and the concept of reflectarrays for high polarization conversion efficiency. The design features a 16-level phase distribution, which allows for high performance of the CGH. Simulation results show that the phase difference between the reflection coefficients approaches π within a wide wavelength range of 600-1000 nm, leading to high diffraction efficiency. The metasurface CGH is fabricated on a silicon substrate and tested with a supercontinuum light source. The results show a high optical efficiency, with the window efficiency reaching 94% in an ideal scenario. The hologram demonstrates a high diffraction efficiency, an extremely low 0th-order efficiency, and a broadband spectral response in the visible/near-IR range. The metasurface has an ultrathin and uniform thickness of 30 nm and is compatible with scalar diffraction theory, simplifying the design of holograms. The study also highlights the potential applications of the metasurface hologram in fields such as laser holographic keyboard, random spots generator for body motion, optical anti-counterfeiting, and laser beam shaping. The approach can be extended from phase-only to amplitude-controlled holograms by changing the size of the nanorods. The technique is limited by the fact that the polarization state of the light cannot be controlled, requiring circularly polarized incident light. The metasurface can be fabricated on a large scale using nano-imprinting, making it a promising candidate for large-scale holographic technology.Researchers at the University of Birmingham have developed a metasurface hologram with 80% diffraction efficiency at 825 nm and a broad bandwidth between 630 nm and 1050 nm. The hologram uses a geometric metasurface (GEMS) design, which consists of an array of plasmonic nanorods with spatially varying orientations. This design allows for superior phase control and high polarization conversion efficiency. The GEMS hologram incorporates a ground metal plane to enhance the conversion efficiency between the two circular polarization states, leading to high diffraction efficiency without complicating the fabrication process. The study addresses the limitations of traditional phase-only computer-generated holograms (CGHs), which suffer from low efficiency and twin-image generation. The proposed GEMS design uses a 16-level phase CGH, combining the concept of GEMS for phase control and the concept of reflectarrays for high polarization conversion efficiency. The design features a 16-level phase distribution, which allows for high performance of the CGH. Simulation results show that the phase difference between the reflection coefficients approaches π within a wide wavelength range of 600-1000 nm, leading to high diffraction efficiency. The metasurface CGH is fabricated on a silicon substrate and tested with a supercontinuum light source. The results show a high optical efficiency, with the window efficiency reaching 94% in an ideal scenario. The hologram demonstrates a high diffraction efficiency, an extremely low 0th-order efficiency, and a broadband spectral response in the visible/near-IR range. The metasurface has an ultrathin and uniform thickness of 30 nm and is compatible with scalar diffraction theory, simplifying the design of holograms. The study also highlights the potential applications of the metasurface hologram in fields such as laser holographic keyboard, random spots generator for body motion, optical anti-counterfeiting, and laser beam shaping. The approach can be extended from phase-only to amplitude-controlled holograms by changing the size of the nanorods. The technique is limited by the fact that the polarization state of the light cannot be controlled, requiring circularly polarized incident light. The metasurface can be fabricated on a large scale using nano-imprinting, making it a promising candidate for large-scale holographic technology.