Study On Sensing Characteristics Of Photonic Crystal Based On The Coupling Analysis Of Optical Tamm State

It is a comparatively novel subject to investigate photonic crystal. The forbidden band and local characteristics can be used to design high performance optical devices.Based on the design and production of photonic crystal structure, the optical sensor with characteristics of small size and high signal response speed, high detection sensitivity and strong ability to resist electromagnetic interference, has become a hot issue in research of optical sensor. Therefore, started from the characteristics of photonic crystal and combing with the surface plasmon resonance(SPR) sensor, a new refractive index sensor structure containing metal layer has been proposed. Then introduced the graphene material to optimize the sensor structure and analyzed its refractive index sensing characteristics, which provides theoretical support for the research of photonic crystal sensor. The research contents are mainly includes as follows:Firstly, based on the optical properties of surface plasma and photonic crystal,new refractive index sensor structure containing metal layer has been designed by the theory of optical Tamm state coupling. The refractive index sensing characteristics is discussed, and the relationship model between the reflection peak wavelength and the reflective index of the sample solution is established. In addition, the periodicity and the incident angle of the photonic crystal are optimized to improve the full width at half maximum(FWHM) of the defect peak and the quality factor(Q value). On this basis, in order to make better spectrum, the photonic crystal layer and the graphene layer have been optimized.Secondly, based on the photonic crystal sensor structure containing metal layer,coating the metal surface with graphene to optimize the sensor structure. The graphene has a higher surface volume ratio and the ? accumulation key can be established between the carbon ring structure of the organic maters and biological molecules and the six-member ring unit of graphene, which makes it fully contact with biomolecules.The graphene also can prevent oxidation of the metal film. According to therelationship between Goos-H?nchen phase shift and the resonant wavelength, the relationship model between the reflection peak wavelength and the reflective index of the sample solution is established.Finally, the sensing characteristics of SPR sensor, photonic crystal sensor structure containing metal layer and photonic crystal sensor structure containing graphene material are analyzed and compared. The results showed that after photonic crystals combined with SPR sensor, the Q values is improved greatly. And the sensing characteristics of the photonic crystal sensor structure containing graphene is higher than before optimization structure, which can demonstrated the advantages of the sensor structure. The structure provides some theoretical references for the design of refractive index sensors with high Q values and sensitivity and displays the design and application potential in optical sensing.