[19a-H116-1~12] 3.16 Optics and Photonics English Session

▲ [19a-H116-8] Bidirectional metamaterial perfect absorbers

〇(P)Nguyen Thanh Tung^1,2, Takuo Tanaka¹ (1.Metamaterials Lab, RIKEN, Japan, 2.Vietnam Academy of Science and Technology, Vietnam)

Keywords:metamaterials,perfect absorber,symmetry

Recently, a new class of artificially engineered materials, the so-called metamaterials, has been studied extensively in the field of optics and photonics. The most noteworthy advantage of metamaterials, which usually contain small inhomogeneous unit cells, is the ability to create macroscopic effective behavior by structural designations. Their unique properties, such as negative refractive index, light bending, and electromagnetically induced transparency, have captured a great interest of scientists owing to promising electromagnetic applications. While absorption loss in metamaterials is unwilling for applications requiring high transmitivity, it becomes an important gain to those relying on electromagnetic radiation probe technologies. In this regard, the concept of metamaterial perfect absorbers has been introduced, magnifying the significance of metamaterials beyond the classical ones. Despite numerous studies have been carried out, metamaterials absorbers are often made up by a dielectric spacer sandwiched between resonators and a metallic ground plane, which have been inherently anisotropic. In this report, we propose a simple approach to bi-directional metamaterial perfect absorbers. This is realized by systematically controlling the losses induced by the electric and magnetic resonance using a symmetric cut-wire-pair metamaterial. It is shown that at the superposition of two resonances, one can obtain a desired absorption without losing the structural isotropy.