Surface Plasmon Resonance Sensing Of Metal Grating Based On RDMS Thin Film

Recent year,micro accepts technical and the superficial plasma optics fast development,has already become more popular research content which the multitudinous scientific researcher favors.When people when research incident light and periodic metal diffraction grating mutual function,has become the model using the metal thin film manufacture diffraction grating model which the researcher uses frequently.Not only the metal thin film structure has the merit which spend little money,light to make,also has the very good future in the practical application aspect.The present paper based on the time domain finite difference method the principle,to one kind which designs take gathers the polydimethylsiloxane(PDMS)thin film as the basis periodic plasma diffraction grating structure simulation model as well as diffraction grating surface plasma resonating the sensing structure to conduct the research and the analysis.The main research contents of this paper are as follows:(1)Introduced the superficial plasma resonating basic principle as well as stimulates the SPR effect the condition and two ways,namely prism coupling and diffraction grating coupling,when theoretical calculation plasma diffraction grating reflection and transmission diffracts the progression and the wavelength relations;Afterwards introduced the diffraction grating SPR sensor two important parameters,namely the refractive index sensitivity and the quality factor,have provided the corresponding rationale for as follows simulation structural model analysis.(2)Proposed one kind of new stress sensitive gathers the polydimethylsiloxane(PDMS)thin film plasma diffraction grating,based on time domain finite difference method(FDTD)principle,structure one kind of structure simulation model,namely periodic plasma diffraction grating model.With the aid of the cycle boundary condition,through to the diffraction grating infliction stress,the transform plasma diffraction grating parameter(i.e.period,duty cycle and the Au film thickness)realizes the resonating wavelength survey,the research diffraction grating parameter to the strength response sensitive degree;Finally makes the simulation result and the theory value the contrast,and obtains the relative error the size.The simulation result indicated,when diffraction grating period p=0.7?m,duty cycle f=55%,golden film thickness b=0.02?m,this time is most sensitive to the strength response;Next,compares the simulation obtained different cycle time resonating wave length and the theoretical value may know the two result to tally;When period for 0.7?m,the resonance peak wave length for 1.251 ?m,obtains through the comparison,the relative error all does not surpass 2%,the result is accurate.(3)Studied in the plasma diffraction grating coupled structure foundation take the PDMS thin film as the basis diffraction grating surface plasma resonating sensing structure,has analyzed changed when some diffraction grating design parameter the refractive index sensitivity and the quality factor performance;Finally obtains under the most superior parameter condition through the analysis sensitivity and the quality factor performance the diffraction grating surface plasma resonating sensing structural model.The result indicated,when the light incidence angle theta for 50°,diffraction grating period p is 0.7?m,golden film thickness b is 0.02?m,duty cycle f is when 55% obtains the diffraction grating surface plasma resonating sensing structure performance achieved superiorly,this time diffraction grating surface plasma resonating sensing structure sensitivity is 1173nm/RIU,the quality factor is19.78/RIU.