Enhancement And Control Of The Interaction Between Light And Graphene By Surface Plasmon And Micro Nano Structure

As the first two-dimensional material,graphene has excellent optoelectronic properties and has bright application prospects in photodetectors,modulators,and new light sources.In order to enhance and control the interaction between light and graphene,based on graphene plasmon and micro-nano resonance structure,an electrically adjustable mid-infrared perfect absorber and polarizer were designed and numerical demonstrated.A nanobeam cavity that resonances near 1THz was also designed and fabricated.The main contents are as follows:1.A tunable perfect absorber based on spatially separated double-layer graphene structure was designed.The simulation results show that the tunable perfect absorption can be realized in the infrared and terahertz bands by rationally designing the structure size of the absorber.The effects of Fermi level,polarization direction,incident angle and structural parameters(insulation thickness,substrate thickness)on the absorption rate were analyzed.2.A polarizer with adjustable polarization direction is designed,and numerical demonstrated that the function of polarizer can be realized and its polarization direction is electrically adjustable.At the same time,when the incident angle is less than 20 degrees,it can still achieve a polarization extinction ratio of more than 20 dB.So the polarizer is insensitive to the incident angle and has a wide-angle polarizing function.3.The principle of high-Q value in nanobeam cavity is analyzed.The general steps of designing nanobeam cavity are given.A high-Q nanobeam cavity is designed.The simulation results show that the cavity has an ultra-high Q of 27422 at the resonance wavelength of 283.53?m.The influence of structural parameters on Q value and resonance wavelength was analyzed.The considerations and design process of designing electronic layout were proposed before making samples.Finally,experimental samples were made.