Application Research Of Photonic Crystal Fiber In Filtering And Sensing

Since the photonic crystal fiber not only has a controllable birefringence effect,but also has strong anti-corrosion and anti-interference characteristics,the optical fiber structure is flexible and variable,and the weight is light and small,so it is widely used in the field of communication and sensing.Combining the high detection sensitivity of surface plasmon resonance technology with the characteristics of a wide range of measurement objects,this paper shows great potential in the field of sensing and communication.The filters and sensors based on surface plasmon resonance of photonic crystal fiber are studied respectively.The filtering performance and sensing characteristics of the finite element are simulated and simulated.The main contents of the thesis are as follows:1.The research background and basic characteristics of photonic crystal fiber are introduced.The main theoretical research methods of photonic crystal fiber are summarized.The theoretical basis of surface plasmon resonance photonic crystal fiber and the choice of filling metal in photonic crystal fiber are given.After that,the numerical calculation method of the mainstream of photonic crystal fiber is introduced.2.This paper presents a surface plasmon resonance(SPR)based polarized photonic crystal fiber(PCF).Gold-plated PCF was studied by finite element method(FEM).The influence of structural parameters on the resonance characteristics is discussed.Numerical simulations show that the resonant wavelength can be modulated by changing the pore parameters and the thickness of the gold layer.The results show that the polarization of one direction can be selectively filtered by adjusting the pore diameter to achieve the filtering effect of the communication band.3.Based on the above model,we designed an improved version of the filter structure in combination with the principle of PCF birefringence.The birefringence effect is enhanced by the change of symmetry,so that the energy of the center is more transferred to the metal coating.In the middle,the difference between the x and y polarization directions and the loss at 1550 nm is increased,and a better polarization filtering effect is obtained.4.We designed a high-sensitivity plasma resonance(SPR)sensor based on photonic crystal fiber(PCF)and analyzed the sensor using finite element software(FEM).The performance of the sensor is improved by introducing a D-type aperture in the first ring of the photonic crystal fiber.We studied the effect of D-well parameters on sensing performance and analyzed sensor performance based on wavelength and amplitude sensitivity.The results show that the proposed sensor has a wide range of refractive index and high refractive index sensitivity.It also has high amplitude sensing sensitivity and high quality factor.