The Research On Au-metalized Nano-layer In Micro-structure Optical Fiber Sensors Based On Surface Plasmon Resonance

The detection and analysis of biochemical materials plays a key role in the aspects ofscientific research, food safety, medical diagnostics, environment protection etc. In recentyears, the research of sensors based on Surface Plasmon Resonance (SPR) has been one ofthe hot topics in the field of testing biochemical materials, especially, the real-timedetection to the unlabeled biochemical materials. Metal-filled photonic crystal fiber(MPCF), not only in terms of surface plasmon effects, but in flexible structure design dueto PCFs, provides a new approach to thinking for the detection and analysis ofbiochemical substances. In this thesis, two kinds of Au-coated PCF-SPR sensors, whichcan be used on frontiers of detecting the refractive index of unknown biomedical analytes,are proposed. The COMSOL Multiphysics based on finite element method (FEM) isemployed to analyze the sensing performance of the proposed sensors and graduallyoptimize the sensor structures. The main contents of this dissertation are as follows:Firstly, with the development status of the PCFs and SPR sensors generalized, theadvantages of the Au-coated PCF-SPR sensors are analyzed.Secondly, based on the Maxwell’s electromagnetic theories, the basic theory anddetecting methods of the PCF-SPR are introduced in detail. And the methods of liquidfilled technology in PCF are also analyzed.Finally, two kinds of PCF sensors based on Au-metalized nano-layer which can beused to realize self-calibration are designed. One is the selection of different fiber opticcore-guided modes for self-calibration, which is used for high accuracy measurement.Refractive index ranges of the detected aqueous are from1.33to1.45. The sensor’ssensitivity is expected to reach10448.5nm/RIU. The other one is the selection of differentplamonic modes for self-calibration to realize high linearity and accuracy with thedetecting refractive index ranges1.46-1.485and1.50-1.52. The sensor’s sensitivities areexpected to arrive at4354.3nm/RIU and4240nm/RIU, respectively.Utilizing of the designed Au-coated PCF sensors based on surface plasmon effects isexpected to achieve with real-time and high sensitivity measurement on biochemical liquid under test. Furthermore, the development of biochemical sensors based on MPCF isexpected to become the next hot topic in the field of specialty optical fiber.