Investigation On Fiber-optic Surface Plasmon Sensing Devices Based On Metallic Micro-Nano Structures

Surface plasmon polaritons(SPPs)is a surface electromagnetic wave which exists at the interface of two mediums with opposite dielectric constant.It have some significant features such as short wavelength,near-field enhancement,localized surface electromagnetic field.These properties of surface plasmons make it have a great application prospect in the field of integrated high-precision nanometer lithography,high sensitivity optical sensing,high-resolution microscope design,and so on.With the development of the surface plasmon resonance(SPR)theoretical research and the progress of micro-nano fabrication technology,development and application of metal micro-nano structure SPR optical elements get more and more attention.This paper conducts a series of theoretical and experimental research on the design of fiber surface plasmon resonance sensors,optimization detection performance and metal micro-nano structure optical integrated devices design by using metal oxide materials and nano-materials.On the basis of the principle of surface plasmon polaritons,by building the structure of optical fiber SPR sensor theory model and carrying out simulation calculation,we design and produce a variety of integrated multi-channel optical fiber SPR sensors.We set the miniaturized SPR sensor detection system and use Lab VIEW software platform to realize dual channel SPR sensor information acquisition and data analysis.We also verify the feasibility of the sensing system through biochemical experiments and achieve integrated high sensitivity SPR sensor chip design based on micro-nano grating and ring array.Major research works are as follows:1.Based on the basic theory of surface plasmon polaritons,this paper expounds the basic properties of SPR wave,introduces the numerical calculation method of surface plasmon polariton devices design and dispersion model of metal materials;build the theoretical model of optical fiber SPR sensor and analyze the influence of different parameters on the sensing performance of the system,optimize the sensing probe;use LabVIEW software to realize data real-time acquisition and analysis for the dual channel SPR sensor.2.Combine optical fiber with metal oxide materials,starting with multi-layer SPR phenomenon,by changing the sensing film system and structure,we design two kinds of dual channel SPR sensing system based on ITO material,Au and Ag materials.Firstly,we analyze the reason why ITO/Au double-layer membrane system in the visible and near infrared region can cause two resonance dips,and detect its sensing property.Refractive index sensitivities of two resonance dips are 1345 nm/RIU and 1100 nm/RIU.Next,we study the influence of Ag/ITO double membrane structure on the sensing sensitivity.On the basis of the single channel research,we design the self-compensated dual channel sensing structure based on concatenation Ag/ITO and Au channel.By using Ag/ITO double-layer structure as a reference channel,eliminate the influence of nonspecific adsorption to molecular specificity recognition effectively and improve the detection accuracy.3.Starting with the chemical synthesis of nanomaterials,we study the effect of different fixation methods of gold nanoparticles to the performance of sensors.We design optical fiber SPR sensor system based on gold nano material and multi-layer membrane structure.Through intensity and wavelength modulation method,dual channel sensing is realized at the same time.Refractive index sensitivities of two resonance dips are 334.1%RIU-1 and 1963.2 nm/RIU.This integrated structure can also realize real-time detection of anti-IgG and Con A molecule.4.We design two kinds of micro-nano optical integrated devices and study their sensing properties.We study the Fano resonance phenomenon of thin metal grating structure under the condition of oblique incidence and give a reasonable explanation to physical mechanism of resonant modes.The structural parameters of thin metal grating are optimized.In the different range of refractive index,different structural parameters of thin grating structure have high refractive index sensitivity and quality factor;We study the subradiant plasmon resonance of gold ring array under the condition of normal incidence and verify its sensing property.Results show the application value of the sensor in the field of high sensitive biological sensing.As a conclusion,we summarize the contents and put forward prospect to further research work.Combined with new nano-materials,nano structures and optical fiber micro-nano structure preparation technology,the sensitivity and integration level of SPR sensor system are expected to be further improved,which make the sensor realize biochemical reaction process real-time monitoring for a variety of biomolecules.