Research On Plasmon-Induced Transparency Based On ?-Structure Of Phosphorene

Black phosphorus two-dimensional materials have many superior properties.Include high room temperature carrier mobility,widely tunable direct band gap,in-plane anisotropy and excellent nonlinear optical response.Therefore,it has broad application prospects in optoelectronic devices.Compared with metal and graphene,it has a wider modulation range and means.In recent years,the phenomenon of plasmonic induced transparency based on phosphorene has gradually attracted people's attention,and it has great potential in slow light and optical switching devices.In this paper,FDTD solutions is used to calculate the plasmon-induced transparency by excimer based on the ?-structure structure of phosphorene.The purpose is to realize wide-range modulation of transparent window in mid-infrared band.The main contents and conclusions of this paper include:(1)Three models based on phosphorene are established: single ?-structure,reverse?-structure cascade and homodromous ?-structure cascade.By comparison,it is concluded that the coupling between bright state and dark state is enhanced,the near-field enhancement is realized,and the intensity of transparent window is significantly improved.In addition,the adjacent dark state coupling in the same direction ? cascade structure weakens the intensity,so the intensity is slightly lower than that in the reverse ? cascade structure.In contrast,the reverse ?cascade structure is more effective.On this basis,the distance between adjacent single ? structures in the inverted ?-structure cascade structure is adjusted to further adjust the intensity of the transparent window.As the distance decreases,the coupling between the dark stripe on the left and the bright stripe in the single ? structure on the right of two adjacent phosphoene nanoribbons increases continuously,and a new transparent window appears.(2)Build a compact ?-structure with smaller size and more potential application.The compact ?-structure eliminates the dark state coupling between neighbors,and reduces the size.The width in the middle can adjust the number and intensity of transparent windows within a fixed wavelength range.The model parameters can adjust the number of transparent windows.Under this structure,it is found that it is sensitive to polarized light.By adjusting the polarization angle of incident light,the intensity of transparent window can be adjusted to achieve the effect of "switching".(3)By changing the Fermi level of phosphorene,the transparent window shows excellent wide-band tunability,in which ultra-wide dynamic control of 5-12 ?m and 15-30 ?m can be performed in X direction and Y direction respectively.Compared with graphene and metal,phosphorene can better realize tunable transparency with wide range,low loss and strong dispersion in the middle and far infrared bands.