| The study on optical properties of complex micro-nano structures has crucial application prospects in the fields of metamaterial design and spatial light field control,etc.which is also one of the hot topics in current research.The existence of surface roughness or defects in the preparation of various micro-nano structures or film-structures has a significant effect on its optical properties.The composite light scattering properties of micro-nano structures features with defects have important research significance on the development and application of design,nondestructive testing,optical manipulation and metamaterial research.This thesis studies the light field characteristics of different micro-nano structures and the composite/difference field light scattering properties with single,double or periodic particles,involving the composite properties of multi-layer particle inlaid or inside the micro-nano surface.Surface plasmon polaritions of the metal nanostructure,the light field control of defect-containing micro-nano surface and the optical micro-manipulation of multi-layer film system are also studied.The following are the research results and innovations of this thesis:1.Based on the basic principle of finite difference time domain method,the two-dimensional calculation model of slightly rough optical surface with targets is established by using the Monte Carlo method.The composite/difference scattering properties of slightly rough optical surface and multi-body particles are systematically studied.The numerical results are demonstrated to analyze the positioning and morphological characteristics of multi-body defect particles and the effect of different factors on the properties of micro-nano structures.2.For the detection problem of periodic defect particles inside the three-dimensional optical surface,the composite light scattering properties between slightly rough optical surface and inside periodic defect particles is discussed.The concept of difference scattering field and the reciprocity theorem are utilize to establish the calculation model which can calculate the difference radar cross section of the periodic defect particles.The frequency-domain’s properties of difference scattering field are studied to find the scattering contribution of periodic defect particles in the total scattering field.And the effects of different factors on the results of optical scattering are analyzed.3.According to the peroperties of surface plasmon polaritons generated on the metal surface of micro/nano structure,the calculation model of micro-nano complex structure is established by utilizing the description of Drude model and the illumination of Gaussian beam.The special conditions of dispersion and excitation of surface plasmon polaritons with different micro-nano structures are studied.The light field on the surface of metamaterials is effectively controlled by the change of micro-nano structure.The concept of defects and roughness is added to the calculation model to explore the properties of surface plasmon polaritons excited on the single layer or multilayer film with complex structure.4.Based on the theory and application of the optical micro-manipulation technology,the discrete Maxwell stress tensor equation which can be suitable for the three-dimensional full-space calculation model is derived to establish the calculation model of arbitrary micro-nano structure.Combined with the plasmon characteristics of complex structure at micro-nano scale,the optical trapping properties of surface plasmon polaritons exerted on nanoparticle is anaylzed.The result indicates the optical trapping force exerted on nanoparticle can be controlled for special movement,transfer,positioning and restraint by designing different structures.And the macroscopic phenomenon is explained by microscopic mechanism.5.Based on the theory of surface plasmon polaritons and the micro-manipulation of nanoparticle,the optical trapping properties of nanoparticle on multi-layered metallic film with periodic structure are studied.The optical manipulation calculation model of three-dimensional micro-nano structures with defects is established to analyze the effects of roughness on the manipulation of surface plasmon polaritons exerted on nanoparticle.The numerical result is verified how to eliminate the negative effect of the surface roughness on the optical trapping force through detailed analysis and discussion,which can provide guidelines for further research on the optical system design and manipulation of arbitrary composite nanoparticles. |
