The Preparation And Properties Of Optical Fiber Sensor Based On Surface Plasmon Resonance

Optical fiber sensing technology has been developed at a high speed along with the optoelectronics and optical fiber communication industries.Compared with traditional sensors,surface plasmon resonance?SPR?based fiber optic sensors have many new detection features and advantages such as compact size,low detection cost,remote online monitoring,and easy reuse and networking.SPR based fiber optic sensors play an important role in solving the biological samples detection at present.Typically,besides the nobel metal such as gold?Au?or silver?Ag?,SPR sensors can be excited in copper?Cu?as well.Cu-coated sensors have sharpest resonant dip and lower cost than gold or silver-coated sensors.In this work,various types of novel structural Cu-SPR fiber optical sensors are studied theoretically and experimentally,and the applications of Cu-SPR fiber optical sensors in biochemistry are also studied.The main research work and achievements are as follows:Firstly,the device and the method for uniformly coating the side of the optical fiber are designed and manufactured,which can not only uniformly deposit multi film,but also flexibly control the film area deposited on the surface of the optical fiber.Secondly,a surface plasmon resonance?SPR?based fiber optic biosensor with bi layers?copper,ITO?has been proposed and demonstrated experimentally.A sensitivity of 4583.4 nm/RIU?refractive index unit?was achieved,with a large enhancement in the figure of merit?FOM?by 61.6%compared to the sample without ITO layer.Furthermore,the proposed SPR-based biosensor exhibits a bovine serum albumin?BSA?solution concentration sensitivity of 1.907 nm/?mg/mL?and a detection limit of 5.70×10^-7 mg/mL.Thirdly,the manufacturing method,parameter optimization and sensing response performance of the core-offset fiber are studied.Based on the analysis and structural characteristics of core-offset fiber transmission spectrum,the Mach-Zehnder?M-Z?interference structure model was proposed.The core-offset fiber sensor with interference resonance peak contrast greater than 15dB is obtained by parameter optimization,the sensing response of whose axial stress,temperature and RI were tested.In addition,a Cu-core-offset fiber SPR sensor was fabricated.And the RI response of the sensor was tested.