Research On The Characteristics Of Refractive Index And Temperature Sensing For Microstructure Fiber Filled With Liquid Crystal Based On SPR

Photonic crystal fiber(PCF)is also known as microstructure fiber,it has more complex structure and unique physical properties comparing with traditional fiber.Metal material can be coated or filled in air holes of the PCF to excite surface plasmon resonance(SPR),and the refractive index of the fiber core can be tuned by infiltrating the temperature-sensitive material liquid crystal(LC)E7 into the fiber core,so that the PCF has temperature sensitivity.In this paper,the refractive index and temperature sensors based on the LC filled SPR-PCF are designed by using the finite element method(FEM)and the mode coupling theory(CMT),which has very important scientific research value and application prospect.The main research results of the thesis are as follows:Firstly,a PCF refractive index sensor coated with gold or silver nanofilm is designed.The performance of the sensor is optimized by changing the diameter of the LC core and the type of coated metal.The refractive index measurement range of PCF reaches1.33～1.37 and the average sensitivity of 1 700nm/RIU is obtained.Secondly,a tunable LC core PCF refractive index sensor based on SPR is proposed.The transmission characteristics of the PCF are changed by tuning the LC core and the thickness of the gold nanolayer.The average sensitivity of the optimized sensor is 10 700nm/RIU in the refractive index measurement range of 1.405～1.445.Thirdly,an asymmetric D-shaped PCF temperature sensor based on SPR is designed.The temperature sensing characteristics of PCFs filled with one,three and five gold wires are studied by FEM.The results show that the average sensitivity of the designed PCF with one and three gold-filled air holes is 3.1nm/℃ in the detection range of 15℃～50℃.Finally,two kinds of LC filled D-shaped PCFs temperature and refractive index dual parameter sensors are studied.The numerical results show that the temperature and refractive index detection ranges of the dual parameter sensor are 15℃～50℃ and1.47～1.55,respectively,and the average sensitivity of 3.2nm/℃ and 2 567nm/RIU is obtained.