| Metamaterials are artificial electromagnetic media with unique and bizarre physical properties,which are of great significance in sensing,imaging and energy acquisition.Hyperbolic metamaterials rely on indefinite dielectric constant,which has a special high anisotropy dielectric properties.The air-metamaterial-air waveguide structure can produce a slow light effect,providing the necessary requirements for light absorption and signal processing.The methods for preparing porous metamaterials are still limited,so a simple method to study colloidal structures with anisotropic geometric structures can provide solutions for the preparation of potential hyperbolic metamaterials;meanwhile existing porous hyperbolic metamaterial waveguide structures The physics and preparation of this also need further study.Therefore,this paper uses the method of polymer self-stretching to construct three-dimensional porous metamaterials,explores the slow light effect of porous hyperbolic metamaterial waveguides,and uses photolithography technology to construct metamaterial slow optical waveguides.Mainly carried out the following work:?1?The three-dimensional periodic inverse opal structure with shape anisotropy was prepared by polymer PMMA stretching,and the optical properties such as anisotropic reflection spectrum,metal plasmon and dielectric non-positivity of shape anisotropic structure were studied.In the temperature range of 100-115?,the anisotropic structure using PMMA self-organized colloidal opal for directional tensile deformation was successfully constructed,and the anisotropic geometric shapes with a stretching ratio of1:1.22 to 1:3.22 were prepared.PMMA inverse opal.The photonic band gap of PMMA inverse opals with different degrees of anisotropic geometry is studied.The wavelength of the photon band gap is related to the length of the long and short axes of the inverse opal pores.When the PMMA inverse opal is stretched,the reflection The peak will move to a short wavelength,and the wavelength change of the photonic band gap is greatly affected by the change of the short axis length.The simulated photonic band gap position change is consistent with the experiment.When gold and platinum are deposited on the surface of an anisotropic inverse opal or conformally coated on its internal interface,the anisotropic optical property is that when the polarization direction deviates from the parallel direction,as the PMMA elongation increases,the surface The cut-off wavelengths of SPP valleys coated with metal-stretched inverse opals and conformal-coated metal-stretched inverse opals gradually increased.When 10 nm gold,copper and platinum are conformally deposited inside the long-short axis 160 nm-80 nm PMMA inverse opal,the dielectric properties corresponding to their structures exhibit non-positive definite dielectric properties,and the corresponding non-positive definite intervals are:1163-1371 nm,1225-1458 nm and 728-778 nm.The non-positive definite interval of 15 nm platinum conformally deposited on the long axis of 351 nm and the short axis of 200 nm anisotropic PMMA inverse opal is 759-805 nm.?2?Using MATLAB to calculate the dispersion equation of the waveguide,the dispersion relation diagram of the hyperbolic metamaterial waveguide of the metal-coated silica rod array structure is drawn,and the dispersion relation result is obtained.Comparing the dispersion relationship between the metal-dielectric stacked layered waveguide and the metal-coated silica rod waveguide,it is found that both have a slow light dispersion relationship.The layered structure has a slow light wavelength in the infrared range of 1.15?m,and the rod structure is slow The wavelength of light is in the range of visible light.The influence of the waveguide width on the slow light dispersion relationship of the rod array structure waveguide is explored.Within 400 nm to 10?m,only when the waveguide width changes,the rod waveguide dispersion curve changes but the wavelength of the strong and slow light is fixed,and the waveguide width is 200?m Above,the slow light effect disappears.The FDTD simulation of the dielectric constant of the rod waveguides coated with different metals was carried out.It was found that the slow light wavelength can be adjusted by adjusting the type of the coated metal.The slow light wavelength of the silver-coated rod waveguide structure is greater than that of the same thickness platinum The rod waveguide is more sensitive to changes in the thickness of the metallic silver,and the slow light wavelength becomes smaller as the thickness of the metal plating increases.The absorption characteristics of the rod-shaped slow-waveguide were simulated,and the non-equivalent medium and the equivalent medium of the rod-shaped waveguide were compared.The absorption peak of the equivalent medium shifted blue as the thickness of the silver plating increased,which was consistent with the slow-wavelength change trend The non-equivalent medium is affected by the metal plasmon,and the change of the slow light absorption peak is slightly different.?3?Using photolithography in combination with an oxidized silica array,an air-porous metamaterial-air waveguide structure construction method was developed.The SU-8 photoresist inverse opal waveguide structure was constructed by colloidal self-assembly method,and the Si O2opal successfully entered the molten SU-8photoresist at 120?;after exposure and development through the mask plate,SU-8photolithography The glue has even grooves.Using FDTD simulation to simulate the air-isotropic/isotropic SU-8 photoresist inverse opal-air waveguide structure,the isotropic/isotropic SU-8 photoresist inverse opal is periodic spherical air or rod-shaped filled with photoresist The structure of air and conformal coating of a layer of metal inside the inverse opal.The absorption spectrum of the SU-8 photoresist inverse opal waveguide structure coated with different metal thicknesses is simulated.The light absorption characteristics of the waveguide structure are good:the absorption of the isotropic waveguide structure coated with 10-20 nm silver is basically above 0.79;anisotropy The absorption of the waveguide structure is higher than 0.8 in the range of300 nm-650 nm.Compared with the effect of the presence or absence of the waveguide structure on the light absorption characteristics of the SU-8 photoresist inverse opal structure,the absorption of the isotropic waveguide structure coated with 5-15 nm silver is generally higher than or equal to the waveguide-free structure in the visible light range;When the thickness is 5-10 nm,the light absorption of the anisotropic waveguide structure in the visible range is greater than that of the non-waveguide structure,and when the silver thickness is greater than 5 nm,the light absorption of the waveguide structure is greater than that of the non-waveguide structure in a certain range,as the thickness of the metal increases The peak position of the ratio of the absorption spectrum of the waveguide structure to the non-waveguide structure is blue-shifted;the absorption of the anisotropic waveguide structure is 1.4 times higher than that of the non-waveguide structure,which is greater than that of the isotropic waveguide structure.The influence of different air layer thickness on the waveguide structure was explored.In the range of 450 nm-800 nm,the absorption of the isotropic waveguide structure of the 50-300 nm air layer is larger than that of the non-waveguide structure;in the range of 550 nm-650 nm,50 The absorption of the anisotropic waveguide structure of the-300 nm air layer is larger than that of the non-waveguide structure.Comparing the light absorption characteristics of the isotropic inverse opal waveguide structure and the anisotropic inverse opal waveguide structure,the anisotropic light absorption is higher than the isotropy in the range of 420 nm to 650 nm.Whether it is isotropic or anisotropic,the waveguide structure can enhance the light absorption of SU-8photoresist inverse opal. |
PDF Full Text Request