Artificial microstructures drive the wave field manipulations to multi-dimension

Lights and sounds are two primary carriers for information. What people see and hear in their daily life is closely related to the light field and sound field. Basically, the main information of the two fields can be described by their amplitude, phase, frequency and a few other attribute dimensions. How to manipulate these dimensions more flexibly and effectively has been an important task for the scientists. However, traditional components for wave field manipulations are often bulky and heavy, which limit the applications of these components in miniaturized and integrated devices. In recent years, the proposal of artificial microstructures has injected new vitality into the field of wave field manipulations and greatly enriched the means of wave field manipulations. Artificial microstructure is a kind of artificial structure with subwavelength size in one or more dimensions. It can resonate with electromagnetic (EM) waves or acoustic waves to achieve functions beyond traditional natural materials. Metamaterials with three-dimensional periodic artificial microstructures and metasurfaces with two-dimensional (2D) artificial microstructures have been widely studied to realize miniaturization and integration of wave field manipulation devices. The response properties of metamaterials and metasurfaces are not determined by the properties of the materials, but largely by the geometric parameters of the artificial microstructures. Thus, by designing artificial microstructures with different shapes and sizes, researchers can realize numerous novel applications, such as left handed metamaterials, holograms, beam deflectors, metalenses and coding metasurfaces. With the development of science and technology, wave field manipulations based on artificial microstructures have gradually extended from one-dimensional manipulation to multi-dimensional manipulation, which have greatly expanded the application scope of artificial microstructures. It also means that the ability of human to manipulate sound and light has been greatly improved. Numerous advanced acoustic and optical devices will continue to emerge with the help of artificial microstructures, and people will have more convenient and diverse ways to obtain and transmit information.

Figure 1 Overview of the multi-dimensional manipulation of wave fields based on artificial microstructures. 

The research group of Prof. Shuqi Chen from Nankai University reviewed recent progresses of wave field manipulations, including EM wave manipulations and acoustic wave manipulations. First, this review focuses on the methods and principles of using metasurface to realize 2D manipulation of wave fields, including the simultaneous manipulation of phase–amplitude, phase–polarization, amplitude–polarization, frequency–phase, and some other 2D manipulations of EM waves. The 2D manipulation of wave fields greatly expands the scope of metasurfaces, which certainly will bring out numerous novel optical devices. For example, by manipulating phase and amplitude of EM waves simultaneously, complex amplitude holograms and energy tailorable multifunctional metasurfaces can be realized. By manipulating phase and polarization simultaneously, vectorial holograms and polarization dependent multifunctional metasurfaces can be realized. By manipulating amplitude and polarization simultaneously, asymmetric transmission devices and chiral metasurfaces can be realized. By manipulating frequency and phase simultaneously, nonlinear phase gradient metasurfaces can be realized. Next, this review introduces the manipulation of acoustic waves from the viewpoint of different acoustic wave dimensions, including the amplitude, phase and energy band structure. Topological Chern insulators, topological semimetals and some other acoustic topological systems based on artificial microstructures are discussed in this section. Subsequently, this review introduces some important optical and acoustic applications based on artificial microstructures, such as structural colors, polarization measurements, optical sensors, optical information encryptions, acoustic holography, metasurface cloaks, and so on. Finally, they discuss some promising research directions in this field, including arbitrary dimensional manipulation of EM waves, on-chip optical dimensional manipulations and manipulation of elastic phonons. This review has entirely summarized recent developments on multidimensional manipulation of wave fields based on artificial microstructures, which are practically important and widely concerned on metamaterials and metasurfaces research area. This review provides a useful guide for researchers trying to realize miniaturized and integrated optical and acoustic devices, and it also has a high reference value for non-professional readers to quickly learn about the field of artificial microstructures. The article is entitled “Artificial microstructures drive the wave field manipulations to multi-dimension” and published in Opto-Electronic Advances Issue 11 2020.

About The Group

Authors of this review article are from the Advanced Photonics and Acoustics in Microstructure (APAM) research group at Nankai University, which focuses on the systematic study of new physical effects and new technology applications of artificial microstructures in the field of wave field manipulations. They proposed the few-layer metasurfaces and found some important coupling mechanisms and symmetric effects between layers. They therefore systematically carried out the study of theories, experiments and potential applications for wave field manipulations by the artificial microstructures. They have published more than 100 high-level articles in Physical Review Letters, Advanced Materials, Light: Science & Applications, Physical Review Applied and some other international journals. More information can be found on the home page of APAM research group: https://chenlab.nankai.edu.cn

Article

Zhang Y B, Liu H, Cheng H, Tian J G, Chen S Q. Multidimensional manipulation of wave fields based on artificial microstructures Opto-Electron Adv 3, 200002 (2020).

DOI: 10.29026/oea.2020.200002