Resarch On New Optical Fiber Sensor Based On Michelson Interferometer

In recent years,the sensor toward to more sensitive,more accurate,more compact direction.The optical fiber sensor has been widely used in metallurgy,high voltage cables,monitoring,bridges,aerospace and military fields because of its low loss of input,large dynamic range measurement,corrosion resistance,anti-electromagnetic interference.To solve the electromagnetic interference,the environment of bad measurement and control problems.The basic principle of the Mach-Zenhder interferometer(MZI),which integrates the sensing part into a single fiber,is using the external environment changes lead to changes in the refractive index within the fiber cladding,thus changing the refractive index difference of the cladding and core,making interference spectrum line drift phenomenon to detect changes in the external environment.This paper is the use of this basic principle to achieve sensing research,the main contents of this study include 1.The structure and characteristics of several popular fiber interferometers are introduced.Then,the traditional interference principle,temperature principle and refractive index sensing principle of interferometer are introduced.On this basis,the temperature and refractive index sensing of different interferometers were studied.2.The basic structure and fabrication process of the transmission peanut-type MachZehnder interferometer are introduced.Based on the basic principle of the on-line integrated Mach-Zehnder interferometer,and when two coupled excitation element is peanut structure,we research refractive index sensing.3.Due to the limitation of the transmission type peanut structure to the environment measurement,the traditional transmission type peanut structure Mach-Zehnder interferometer was simplified and improved,the sensing characteristics of reflection structure of peanut type Michelson interferometer are discussed.The refractive index sensing of the structure and the temperature sensing characteristic at 50-500 ? are studied.The production process of reflection peanut type structure is described in this paper,and proposes a method for encapsulation the end face of the fiber.It is only the reasonable to protect the smoothness of the fiber end face,it will not affect the Fresnel reflection.4.An array of microspheres structure is composed,which is fabricated by three microspheres structure using fiber fusion splicer and microscope cutting device.The refractive index sensing of the reflection Michelson interferometer characteristics was research.Due to the structure for the temperature sensing more sensitive,segment measurement scheme 50-90°C,500-570°C are adopted.