Multi-function optical switch and optical storage based on synergistic triple plasmon-induced transparency

Conventional plasmon-induced transparency (PIT) typically relies on direct coupling between bright and dark modes. To further expand the application potential of PIT, the exploration of new coupling mechanisms based on bright and dark modes has become an important research direction. In this paper, we propose a hypersurface consisting of two longitudinal graphene ribbons and five transverse graphene strips, which is capable of generating a significant triple-PIT through the synergistic effect between two single-PITs, breaking through the limitation of the traditional coupling of light and dark modes. The study reveals that the metasurface is capable of achieving dynamic switching for asynchronous optical modulation, with the quad-frequency asynchronous optical switch exhibiting exceptional modulation depth (MD) (93.2% < MD < 99.7%), insertion loss (IL) (0.14 dB < IL < 0.81 dB), and extinction ratio (ER) (11.7 dB < ER < 26.3 dB). In addition, the triple-PIT system exhibits a group index as high as 1109, indicating its excellent potential application in optical storages. Thus, this study is expected to provide new theoretical guidance and technical ideas for the design of multi-function optical switches and optical storages with important application prospects.