15 Nov 2013 | Xingjie Ni, Alexander V. Kildishev & Vladimir M. Shalaev
This article presents an experimental demonstration of ultra-thin metasurface holograms that operate in the visible range, with a thickness of only 30 nm (approximately 1/23 of the operational wavelength). These holograms can modulate both amplitude and phase of the wavefront scattered by an object, enabling high-resolution, low-noise images. The metasurface holograms are fabricated using nanostructured plasmonic nanoantennas, which allow for subwavelength-scale control of both amplitude and phase. The design involves a set of Babinet-inverted, complementary nanoantennas (CNAs) that provide specific phase shifts to the cross-polarized, scattered light. The metasurface hologram modulates both amplitude and phase on a subwavelength scale, leading to a conceptually much higher diffraction efficiency than traditional holograms. The experimental results show that the metasurface holograms can produce clear images of the word 'PURDUE' at a wavelength of 676 nm, with a resolution of less than 8 × 8 μm². The metasurface holograms also exhibit a signal-to-noise ratio of 24.4, demonstrating their potential for practical applications. The study highlights the advantages of metasurface holograms in terms of flexibility, compactness, SNR, and image resolution. The results show that the metasurface holograms can be used in both transmission and reflection modes with the same design. The study also discusses the potential for further optimization of the metasurface holograms to build more compact, efficient, and versatile optical components for planar optics, conformal nanophotonics, and display devices. The article references several previous studies on holography, metasurfaces, and plasmonic nanoantennas, and provides a detailed description of the design, fabrication, and characterization of the metasurface holograms.This article presents an experimental demonstration of ultra-thin metasurface holograms that operate in the visible range, with a thickness of only 30 nm (approximately 1/23 of the operational wavelength). These holograms can modulate both amplitude and phase of the wavefront scattered by an object, enabling high-resolution, low-noise images. The metasurface holograms are fabricated using nanostructured plasmonic nanoantennas, which allow for subwavelength-scale control of both amplitude and phase. The design involves a set of Babinet-inverted, complementary nanoantennas (CNAs) that provide specific phase shifts to the cross-polarized, scattered light. The metasurface hologram modulates both amplitude and phase on a subwavelength scale, leading to a conceptually much higher diffraction efficiency than traditional holograms. The experimental results show that the metasurface holograms can produce clear images of the word 'PURDUE' at a wavelength of 676 nm, with a resolution of less than 8 × 8 μm². The metasurface holograms also exhibit a signal-to-noise ratio of 24.4, demonstrating their potential for practical applications. The study highlights the advantages of metasurface holograms in terms of flexibility, compactness, SNR, and image resolution. The results show that the metasurface holograms can be used in both transmission and reflection modes with the same design. The study also discusses the potential for further optimization of the metasurface holograms to build more compact, efficient, and versatile optical components for planar optics, conformal nanophotonics, and display devices. The article references several previous studies on holography, metasurfaces, and plasmonic nanoantennas, and provides a detailed description of the design, fabrication, and characterization of the metasurface holograms.