Plasma metamaterials as cloaking and nonlinear media

Abstract

Plasma metamaterials, composites of lowtemperature plasmas and periodic functional microstructures, work as cloaking and nonlinear media. Due to functions of the microstructures like negative permeability, electromagnetic waves in and around plasma metamaterials propagate in a quite different manner from the case with the conventional space in which relative permeability is positive and unity. Using plasmas and plasma metamaterials, we achieve various controls of microwave propagating paths such as unidirectionality and cloaking in the two or 3D spaces. For instance, a concentric plasma layer makes wave propagation unidirectional, and waves propagate in different routes when they start inside or outside the concentric layer. Furthermore, due to spatial permittivity gradient and anisotropic refractive index, electromagnetic waves detour in plasma metamaterial layers. Another significant point that plasma metamaterials can realize is nonlinearity. When we study highpower electromagnetic waves propagating in them, we observe several properties describable in terms of nonlinear dynamics and nonlinear photonics. Microwaves beyond threshold energy trigger bifurcations in plasma permittivity, and the second harmonic wave detected simultaneously is generated with strong emission levels. Such electromagnetic wave propagation is achieved with advantages over other materials, since plasmas and metallic microstructures work in harmony and in synergy.

Spatiotemporally Controllable Plasma Lattice Structures in Dielectric Barrier Discharge

“…So far, there have been some proposals to make tunable PCs via mechanical, thermal, biological, and optofluidic methods [5][6][7][8]. Recently, increased efforts have been made using plasma photonic crystals (PPCs) as a special "meta"-material by use of the plasma dispersive properties and the active temporal switching capabilities [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. These have led to some dynamic devices for electromagnetic waves, such as the plasma lens, plasma antenna, plasma stealth aircraft, and so on.…”

“…Generally, four methods are implemented to produce tunable PPCs in experiments. First, an array of metal electrodes or an array of discharge tubes are utilized to generate periodic plasma columns whose symmetries are * fanweili@hbu.edu.cn right commensurate with the artificial structures [10][11][12][13][14][15]. Second, PPCs are fabricated either by inserting an arrangement of solid rods (dielectric or metal) into the plasma background, or in reverse, producing periodic plasma rods in a solid background [17,18].…”

A Novel Temperature Controlled Broadband Metamaterial Absorber for THz Applications

“…Recently, metamaterials have been received considerable attentions from scientific and engineering communities due to the feasibility of artificially designed material properties since the concept was first introduced theoretically [1]. Composed of sub-wavelength resonator with three-layer structure of metal-dielectric-metal, the metamaterials exhibit exclusive phenomenon [2], such as polarization rotation [3]- [5], flat focusing lens [6], invisibility cloaking [7], [8], phase manipulation [9] and so on. Also, the metamaterial absorber was widely investigated as a result of the potential applications in stealth technology [7], [8], thermal emission [10] and photodetection [11].…”

“…Composed of sub-wavelength resonator with three-layer structure of metal-dielectric-metal, the metamaterials exhibit exclusive phenomenon [2], such as polarization rotation [3]- [5], flat focusing lens [6], invisibility cloaking [7], [8], phase manipulation [9] and so on. Also, the metamaterial absorber was widely investigated as a result of the potential applications in stealth technology [7], [8], thermal emission [10] and photodetection [11]. The first metamaterial absorber was studied in 2008 [12]; after that, a variety of metamaterial absorbers from single band [12]- [14] to multi-band [15], [16], from narrow band [12], [13] to broad band [17]- [20], from polarization-sensitive [21] to polarization-insensitive [22]- [24] have been reported for microwave, THz, even optical applications.…”

Frequency‐agile microstrip resonator using DC plasma discharge

“…In this context, non‐magnetised low‐pressure non‐equilibrium plasma (cold plasma) offers a reliable solution [2]. Plasma has been investigated to provide original solutions for microwave power limitation [3], radiation [4], stealth [5], and frequency tuning where the plasma was considered as a lumped element [6]. Its electron density may indeed be controlled to change its dielectric permittivity and hence enable frequency agility.…”