Research On Plasmon-Induced Transparency Phenomenon Based On Graphene Metamaterials

Electromagnetic metamaterials offer versatile control over electromagnetic waves,resulting in improved functional device models for micro and nanophotonics applications.Plasmonic Induced Transparency(PIT),as one of the research branches in the field of metamaterials,can solve the problems of optical flux control,optical speed regulation,optical storage design,nonlinear optics and refractive index sensing measurement in micro and nano structures,and is one of the optional functionalized structural units for future nanophotonic chips.In this paper,based on graphene metamaterials,the equipartition Plasmonic-induced transparency phenomenon is the main research object,and the simulation experiments are performed by finite-domain difference method,and Lorentz theory and coupled mode theory are used to theoretically analyze and summarize the laws of PIT phenomenon.The current tunable PIT devices exhibit limited tuning freedom and lack a clear application context.Therefore,this study utilizes simulation software to investigate the practicality of PIT functional devices and to enhance their performance by adjusting key parameters.The following are the corresponding works performed:1.We designed a triple-channel asynchronous filter based on patterned graphene.By changing the Fermi energy level from 0.2 e V to 1.2 e V,both simulation and theoretical calculations showed a tuning bandwidth of 3.67μm–9.53μm when the graphene layers N=3,which can cover two atmospheric windows effectively.In addition,the control of the PIT effect on/off is realized by changing the polarization angle.Based on this,triple-channel asynchronous filtering or optical switching can be realized.Device performance analysis shows that a 90%modulation depth and low insertion loss can be achieved at a relatively high Fermi energy level.Therefore,our design achieves a dynamically tunable triple-channel asynchronous filter in the atmospheric windows.Considering the ultrathin characteristics of metasurfaces and the high modulation rate brought by the high carrier mobility of graphene,integrating this device into an infrared detector can achieve multi-channel dynamic filtering while improving the integration level and response rate of the infrared detector.2.We have designed a multifunctional device based on a metamaterial-waveguide hybrid system that can generate three Plasmonic Induced Transparency(PIT)effects,with each PIT having a different construction principle.Specifically,PIT-I can switch between PIT and BIC by changing the Fermi energy level,while PIT-III is formed by the near-field coupling of a low-Q wideband bright mode and a high-Q dark mode,both of which have a high quality factor Q,which is a key indicator for improving the performance of slow light devices and refractive index sensors.Regarding sensing,PIT-I can achieve a sensitivity of S=0.30 THz/RIU and Figure of Merit(FOM)=15.3,showing good sensing performance,with the adjustable FOM being a standout advantage in our design.In terms of slow light,when E_f=0.6 e V,the group delay of PIT-I can reach 29.5 ps,while when E_f=1.0 e V,the group delay of PIT-III can reach 105.7 ps.Therefore,our design exhibits good performance in slow light.Additionally,this device has potential applications in areas such as multi-frequency optical switching and narrowband filtering.This design approach based on different mechanisms also provides a potential idea for the design of multi-PIT functional devices.This paper presents research findings on the implementation of various functions of PIT devices using graphene metamaterials.By improving device performance through structural design,this study offers optional design solutions for micro and nano-photon functional devices.