Research On The Preparation And Characteristics Of Few Mode Optical Fiber Sensors

In recent years,the optical fiber sensor has been used widely in industrial,mechanical equipment,power systems and other fields,which due to the characteristics of small size,anti-interference ability and adaptability.Few mode fiber(FMF)not only has the low nonlinearity characteristic of multi-mode fiber,but also the low transmission loss and low mode dispersion characteristics of single-mode fiber.So it has gradually become the research focus of new sensor.Therefore,it is of great significance to research various types of sensors based on FMF.In this paper,the research status of the modular interference optical fiber sensor and the FMF sensor at home and abroad is researched,and a cascading FMF sensor is proposed.The temperature,curvature,strain,refractive index sensing characteristics have been explored.The main content is included as follows:Firstly,the research status of FMF and module interference sensor is analyzed,and the realization method of the module interference sensor is introduced,and the research contents of this paper are described.Secondly,the preparation and principle of FMF sensor are discussed.The internal light field and mode of the FMF are analyzed.The relationship between the FMF length and the transmission spectrum is discussed.The transmission mode and the FMF length with the interference are analyzed.And the temperature and refractive index sensing characteristics with the different FMF length are studied.The experimental system is constructed.For different FMF length,the refractive index and temperature experimental results are discussed.Finally,the tensile,torsion and curvature sensing characteristics are studied.For different FMF length,the tensile,torsion and curvature experimental results are analyzed and discussed.