Study On Surface Plasmon Resonance Sensor For Terahertz Waves

With the development of Terahertz(THz)science and technology,there have been new and exciting research directions,including Terahertz Surface Plasmon Polaritons(SPPs).The SPPs become a hot subject with interesting features,such as beam splitting,beam amplification,tuning,and filtering.It has received more and more attentions due to its applications in sensing technology.The principles of THz-SPPs are presented first in this dissertation,and the THz Surface Plasmon Resonance(SPR)is described as the key point.Then the THz-SPP sensor's working principle,design parameters,fabrication method and applications are described gradually by theoretical analysis,the relevant device design and experiment.The main contents are classified as follows:1.Based on the theory of solid-state physics,Drude model is used to solve the dielectric function of the conductor in electromagnetic field and the expression of Bulk Surface Plasmons(Bulk SPs).Then the classified Maxwell's equations are derived to find out the relationship between SPPs and Bulk SPs,and the properties of SPPs dispersion are obtained.Several methods for exciting SPPs are introduced.2.The factors affecting SPR are discussed,which include the permittivity of the dielectric,the period of the metal structures,the thickness of the metal,the size and shape of the sample cells.The main factors which affect the central frequency of the resonance are the dielectric permittivity and period.The quality factor of the SPR is discussed,and the parameters affecting the Q factor are also discussed.3.The quantitative conversion relationship in SPP sensing has been found out.The concept of SPP sensor is given.Considering the principle of SPP,the sensor processing applications,and design principles are determined.The fabrication method of the SPP sensor is introduced.4.A specific size of the commercial metal hole array is chosen based on the theoretical analysis and calculation.The purpose of the experiment is to distinguish different grades of gasolines.The gasolines have been experimental tested using board band terahertz time-domain spectroscopy both with and without the SPP sensor.The results indicate that the SPP sensor could efficiently distinguish between different grades of commercial gasolines in the market.