A broadband optical diode for linearly polarized light using symmetry-breaking metamaterials

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Complete amplitude and phase control of light using broadband holographic metasurface

Reconstruction of light profiles with amplitude and phase information, called holography, is an attractive optical technique to display three-dimensional images. Due to essential requirements for an ideal hologram, subwavelength control of both amplitude and phase is crucial. Nevertheless, traditional holographic devices have suffered from their limited capabilities of incomplete modulation in both amplitude and phase of visible light. Here, we propose a novel metasurface that is capable of completely controlling both amplitude and phase profiles of visible light independently with subwavelength spatial resolution. The simultaneous, continuous, and broadband control of amplitude and phase is achieved by using X-shaped meta-atoms based on expanded concept of the Pancharatnam-Berry phase. The first experimental demonstrations of complete complex-amplitude holograms with subwavelength definition are achieved and show excellent performances with remarkable signal-to-noise ratio compared to traditional phase-only holograms. Extraordinary control capability with versatile advantages of our metasurface paves a way to an ideal holography, which is expected to be a significant advance in the field of optical holography and metasurfaces

Metasurface-based reconfigurable visible light absorber

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Dual-mode metasurface: Simultaneous control of phase and spectral responses

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Dual-mode metasurface: Simultaneous control of phase and spectral responses

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Ultra-High Refractive Index of Optically Transparent Hydrogenated Amorphous Silicon for a Low-Cost Functional Photonic Device at The Visible Frequencies

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Challenges in fabrication towards realization of practical metamaterials

Metamaterials, artificially structured materials consisted of sub-wavelength unit cells, have attracted tremendous attentions in physics, material science, and engineering over the past decade. Many exotic and extraordinary electromagnetic phenomena such as negative refractive index, invisibility cloaking and super-resolution imaging have been realized through metamaterials. Now, metamaterials need to be focused on nanoscale optical metamaterials, operating at ultra-violet (UV), visible and near-infrared (NIR) frequencies for practical applications of them. Here, we review the fundamentals, recent progress, main challenges, and future direction of optical metamaterials and related fabrication processes. The fundamentals and recent progress of the optical metamaterials are discussed with representative examples such as negative index metamaterials and invisible cloaks. Main challenges in fabrication for practical metamaterials, three-dimensional and large-scale metamaterials, and brief discussion about the outlook for the next generation scalable nanofabrication methodologies are followed. (C) 2016 Elsevier B.V. All rights reserved.1197Nsciescopu