Mie Theory Study On The Optical Properties Of Multi-particle Core-shell Structure

In the past ten years,significant progress has been made in research based on surface plasmons.Surface plasmon nano-photonics,as a cutting-edge cross-discipline,a science that studies the interaction of light and matter.Under the condition of breaking the optical diffraction limit,it has been developed rapidly.Surface plasmon nanophotonics has a wide range of applications in the fields of nano-level optical manipulation,single-molecule level biological detection,sub-wavelength aperture light transmission enhancement,and ultra-high-resolution optical imaging.Since the research object is sub-wavelength size,theoretical calculations play a significant role in the research process.As calculation method for simulating plasmon,Mie theory has become a powerful tool for the study of spherical nanoparticles due to its fast calculation speed and accurate result.However,the code based on the Mie theory is shortage,the study expands the existing Mie codes and uses the code to realize the optical properties of simple structure.The specific work is as follows:(1)Covert the theoretical hybridization of the spherical shell structure into MATLAB code and combine it with the multi-sphere coupling part.Synthesized and optical characterized metal nanoparticles.The results can provide references for the application of surface plasmons in many fields.For example,the use of the relationship between the core-shell structure parameters and field enhancement effects can provide a reference for improving the signal strength of Surface Enhanced Raman Scattering(SERS),which can be used detection fields and others.(2)Using the extended Mie code to study the strong interaction between the plasmon and the chiral molecule of the spherical core-shell structure.It is found that the geometric parameters of the structure and the change of the oscillator strength of the chiral layer will improve the ability of chiral layer induce CD response of plasmon.And using extended Mie code combined with the commercial software COMSOL to study the deviation of enhancement factor and radiation enhancement factor of the SERS enhancement factor calculated by the plane wave approximation method of the common SERS structure,and also used the Purcell factor to estimate the radiation enhancement.For the spherical shell and multi-particle structure,this thesis extended the existing Mie code and realized the simulation of the multi-particle core-shell structure.The research on the extended Mie code,the related chiral shell structure and the SERS enhancement factor is instructive for the promotion of the Mie theory,the study of the unique optical properties of metal nanospheres and the selection of the calculation method for the SERS enhancement factor.