Research Of Fiber Sensor Based On Cascaded Spherical-shape

Optical fiber sensor,especially the sensor based on Mach-zehnder(M-Z)interferometer has been deeply researched and developed in recent years,and its application to the measurement of the external physical characteristics is becoming a hotspot.The work of this paper is to study the theory,fabrication and application of optical fiber sensor,and cascade two simple spherical structure optical fiber sensor together to research its performance on measuring external physical characteristics to discuss its potential applications prospects.The details are arrange as following:1.Referring to a large number of references,to introduce the development background,fabrication principle and development prospect of the spherical structured optical fiber sensors.Discussing the characteristics with different length by fabricating optical fiber sensors with different length and simulating with software Rsoft,2.A fiber Mach-zehnder interferometer composed of three spherical structure is fabricated.In this paper,the manufacturing steps and methods of the spherical sensor are introduced.When three spherical structures are distributed symmetrically,the sensitivity of the sensor to temperature,refractive index and micro displacement is-0.1nm/?,-118.17nm/RIU and-0.073nm/?m,respectively.When the three spherical structures are asymmetrical,the sensitivity of the sensor is-0.091nm/?,-101.64nm/RIU and-0.089nm/?m,respectively.3.Cascade two identical spherical structure sensor to discuss the influence on the interference spectrum of different cascaded length.The influence of different cascade length on the sensitivity of the sensor is studied by measuring the external physical characteristics to explore more applications of the cascaded sensors.