Research On High-Q Plasmonic Lattice Resonance Metamaterials Nanobiosensor

Under the nanometer scale,exploring the law of interaction between light and matter and discovering new physical effects are important research contents of nanophotonics.Surface plasmon polaritons（SPPs）can confine light to subwavelength scales and enhance the interaction between light and matter,but the inherent ohmic heat and external radiation losses in metal nanoparticles severely limit the application of SPPs in optical devices.Therefore,in order to overcome this difficulty,this thesis adopts the general strategy of multiple coupling effects to achieve high quality factor（Q）by exciting surface lattice resonance,Fano resonance and other optical effects in the lattice array.The radiation loss in the plasmonic nanostructures can be suppressed,and the sensitivity of the surrounding light field to the background refractive index is greatly improved.It has important research value for the development of a new generation of low-power,highly-integrated,high-sensitivity nano-biosensors.In this thesis,high-Q plasmonic biosensors with lattice array structure are mainly studied.First,the Fano resonance and surface lattice resonance based on surface plasmons in metamaterials are explored,and the research progress at home and abroad is reviewed;then,the dispersion relationship and excitation mode of surface plasmons are studied;Two numerical methods:Finite Difference Time Domain（FDTD）and Finite Element（FEM）numerical simulation methods are discussed;finally,Metal-Dielectric-Metal（MIM）waveguides,MIM gratings and hybrid waveguides are designed Three structures of metamaterials.The characteristics of quality factor（FOM）,quality factor（Q）and refractive index sensing（S）are analyzed and discussed in depth respectively.The specific research contents are as follows:1.A high-Q plasmonic filter and sensor with MIM waveguide structure are designed.By exciting the F-P-like resonance in the resonant cavity,two prominent resonance peaks appear simultaneously in the near-infrared band.The research results show that the sensitivity is S₁=1200 nm/RIU and S₂=900 nm/RIU in the refractive index range of1.00～1.20,respectively.In addition,it can provide a theoretical basis for the design of tunable dual-channel bandpass filters working in the communication windows of 850 nm and 1310 nm.2.A lattice resonance refractive index sensor with MIM grating structure is designed.Through the coupling of metal localized surface plasmon resonance and WA（-1,0）,a surface lattice resonance with a Q factor of up to 1064 can be achieved in the near-infrared band;an electric quadrupole mode is generated in the dielectric space between the metals,resulting in relatively Broad plasmon resonance peak.The calculated results show that the refractive index sensitivity of both modes is 310.7 nm/RIU.This research provides a theoretical basis for designing narrow-band,high-Q-factor optical sensing devices in the near-infrared band.3.A high-Q multi-Fano resonant hybrid waveguide metamaterial refractive index sensor is designed.Exciting the coupling of metal localized surface plasmon resonances with dielectric waveguides by hybrid waveguide metamaterial structures enables efficient tailoring of multiple Fano resonances in the visible wavelength range.The numerical calculation results show that the ultra-narrow linewidth,quality factor and Figure of Merit can reach 1.7 nm,690 and 236,respectively.The refractive index sensing sensitivity is about 200 nm/RIU.This conclusion has potential application value in other fields such as next-generation plasmonic high-resolution,label-free biochemical sensing,and narrow-band detection.