Highly efficient tunable terahertz all-dielectric metasurface absorber based on high mode

All-dielectric terahertz metasurface absorbers have aroused widespread attention over the past few years for their flexible design concepts and excellent absorbing properties. However, the existing all-dielectric terahertz metasurface absorbers are subjected to poor tunability. In this study, a high-efficiency magnetically tunable terahertz all-dielectric metasurface absorber scheme is proposed based on high modes. In this paper, the all-dielectric metasurface is compounded with the liquid crystal, and the device can be tunable by different applied magnetic fields. The results show that the absorption peak of the device is very sensitive to different applied magnetic fields. By studying the tunable performance of the first three levels of Mie resonance peaks of the absorber, we found that the device has efficient tunability in high mode and optimized the design of the all-dielectric metasurface absorber with the tuning figure of merit (FOM) of up to 6.67. This scheme shows the advantages of simple fabrication, low cost, and high integration, and it will provide a novel idea for the design of highly efficient terahertz tunable all-dielectric metasurface absorbers. Graphical Abstract In the terahertz range, this work proposes to composite the all-dielectric metasurface and liquid crystal, and it is found that under the high mode of Mie resonance, the dielectric properties of the liquid crystal change due to the applied magnetic field, so as to realize the efficient active tuning of the absorber absorption peak.