From Single‐Dimensional to Multidimensional Manipulation of Optical Waves with Metasurfaces

Abstract

given refractive indices. The limited refractive indices of natural materials prevent the generation of new optical phenomena. The size and weight of traditional optical devices also prevent optical system miniaturization and integration. Nowadays, there is an everincreasing demand for new approaches to implement the effective manipulation of optical waves in different dimensions and to get the novel optical devices on demand.With the development of nanofabrication technology, artificial nanostructures become approachable which offer a promising solution to the achievement of efficient manipulation of optical waves in different dimensions. Metamaterials, which attain their optical functionalities from the subwavelength structures rather than their constitutive materials, provided intriguing possibilities for the evolution of modern optics and have attracted great interest from the scientific community over the past twenty years. [1][2][3] By judiciously modulating their subwavelength structure parameters, the effective values of the permeability and permittivity of the metamaterials can be designed on purpose to realize the manipulation of optical waves in a spectific dimension and to get the desirable optical functionalities, which are even not achievable with natural materials. Previous works have demonstrated that metamaterials can be widely applied in realizing negative refractive index, [4][5][6] electromagnetic invisibility cloaks, [7,8] optical black holes, [9] chiral media, [10,11] and so on. However, the commercialization of metamaterial-based optical devices in real applications is still challenging, which we ascribe to the strong dispersion and high losses associated with typically used metallic structures, and also the difficult and costly fabrication for 3D designs.Recently, planar metamaterials or metasurfaces have received great attention for their advantages to meet these challenges. [12][13][14] Compared to metamaterials, metasurfaces, as artificial planar designs, have dramatically reduced the fabrication complexity. Moreover, the thickness of metasurfaces is less than or similar to the wavelength of operating waves, which results in the reduction of the undesirable losses and offers an effective manner for implementing tunable and reconfigurable optical devices. Overall, metasurfaces provide an effective way to overcome the challenges in metamaterials, and it has been successfully proven that metasurfaces are more feasible for the engineering of the fundamental dimensions of optical Metasurfaces, 2D artificial arrays of subwavelength elements, have attracted great interest from the optical scientific community in recent years because they provide versatile possibilities for the manipulation of optical waves and promise an effective way for miniaturization and integration of optical devices. In the past decade, the main efforts were focused on the realization of single-dimensional (amplitude, frequency, polarization, or phase) manipulation of optical waves. Compared to the metasurfaces with sing...

A Bilayer Plasmonic Metasurface for Polarization‐Insensitive Bidirectional Perfect Absorption

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Controllable Polarization Rotator with Broadband High Transmission Using All‐Dielectric Metasurfaces

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