Research On The Principle And Characteristics Of Sensors Based On Surface Plasmon Polariton

The field of surface plasmon resonance(SPR)sensors has become more and more widely used,when the refractive index of the medium to be tested changes slightly,the sensor can sense this change for the purpose of sensing.The theory of attenuated total reflection and evanescent wave is introduced in the theoretical part of the paper,and highlights the conditions that stimulate the SPR effect,introduced several common SPR excitation structures.Several SPR sensor models are designed,change the parameters of the SPR sensor model,simulation using FDTD Solution simulation software,calculate sensor sensitivity and quality factor,then analyze and compare.A rectangular grating-glass composite SPR sensor was studied.A 20 nm deep rectangular grating was etched on a 50 nm thick silver film.Changing the period of the rectangular grating,and comparing the sensitivity and quality factor of single-metal SPR sensors,on this basis,the depth of the groove was set to 30 nm,comparing the sensitivity and quality factor of SPR sensors with grating under groove depth of 20 nm.Based on a groove depth of 20 nm and a rectangular grating period of 48 nm,changing the height of the rectangular raster,analysis and comparison of sensitivity and quality factors corresponding to different grating height structure SPR sensors was processed.When changing the thickness of the Ag film,analysis of the variation of the resonance effect of the SPR sensing device by the reflectance curve.A triangular grating-glass composite SPR sensor was designed,etching a triangular grating with a depth of 20 nm on a silver film with a thickness of 50 nm,changing the period of the triangular grating,comparing sensitivity with single-metal SPR sensors,then compare the sensitivity of the SPR sensor with a rectangular grating-glass composite structure.Silver-gold bimetal SPR sensor has the advantage of stable chemical properties.Based on a silver-gold SPR sensor with a silver film thickness of 20 nm,a gold film thickness of 30 nm and a silver-gold SPR sensor with a silver film thickness of 30 nm,a gold film thickness of 15 nm,a bimetallic rectangular grating-glass composite structure SPR sensor is designed,change the period of the rectangular grating,comparing the sensitivity and quality factor of bimetallic SPR sensors,change the height of the rectangular raster,analyze the sensitivity and quality factor of SPR sensors with different grating heights.When changing the thickness of Au film,analysis of the variation of the resonance effect of the SPR sensing device by the reflectance curve.For SPR sensors with a silver film thickness of 20 nm and a gold film thickness of 30 nm,change the groove depth of the gold film grating to 15 nm,20nm and 25 nm,calculate the sensitivity and quality factor of the corresponding structure separately,then compare and analyze.