Multiresonances of Quasi-Trapped Modes in Metasurfaces Based on Nanoparticles of Transition Metal Dichalcogenides

Abstract

The features of polarization control of multiple multiresonances for quasi-trapped modes excited by synchronization of bianisotropic dipole responses in MoS2 disks with a hole are considered. Using numerical calculations with analytical multipole analysis, we showed that the presence of a strong optical anisotropy of MoS2 nanoparticles provides an additional degree of freedom and makes it possible to observe several resonances of electric and magnetic dipoles at once in a narrow spectral range. Based on the simulation results, we obtained the frequency dependences for the dipole polarizabilities of the MoS2 disk with a hole, which can be used to distinguish the contributions of the nonlocal and bianisotropic dipole responses and possessing several features in the near-infrared range. Using the polarizability spectra of single nanoparticles and applying the tuning strategy, the design of the MoS2 metasurface placed in air and supporting three resonances of quasi-trapped modes at once in a narrow spectral range was developed. One of these resonances corresponds to the telecom wavelength of about 1550 nm. The spectrum of light reflection for the MoS2 metasurface is characterized by three narrowband dips corresponding to the wavelengths of the quasi-trapped modes. It was shown that a change in the polarization of a wave normally incident on the metasurface to orthogonal one leads to a change in the type of bianisotropic response excited in each MoS2 disk and to the excitation of three other features in the reflection spectrum of the metasurface at wavelengths close to the initial values.

Keywords

• metasurfaces
• transition metal dichalcogenides (TMDCs)
• quasi-trapped modes (QTMs)
• polarizing control
• bianisotropic response