Study on all-optical tunable terahertz slow-light effects based on polarization-insensitive metamaterials
The terahertz(THz)slow-light effect can effectively improve the security and memory proper-ty of THz pulse data during transmission.However,the general THz slow-light devices are sensitive to the polarization state changing of the incident THz wave.In this paper,we design a metamaterial struc-ture whose unit cell consists of one cross resonator and four U-shaped resonators.The results show that the THz slow-light effects based on metamaterials are not sensitive to both linear and circularly polarized light.A slow-light effect with the maximum group refractive index of 1618 is obtained by optimizing pa-rameters of the metamaterial structure.A molybdenum disulfide film between the metamaterial micro-structure layer and the SiO2 substrate is embedded.When the carrier concentration of molybdenum disul-fide increases from 1.7 ×1017 cm-3 to 5.1×1019 cm-3,the group refractive index decreases from 1566 to 26,and a polarization insensitive all-light tunable THz slow-light effect is realized.This study can pro-vides some new ideas for the design of polarization insensitive and all-light tunable THz slow-light de-vices.
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万方数据
维普
