Research On All Fiber Mach-Zehnder Interferometer Sensor

With the rapid development of optoelectronic technology industry,the development and application of optical fiber sensors have been improved rapidly.The optical fiber sensor has obvious advantages over the traditional electrical sensor.The optical fiber sensor has the advantages of anti electromagnetic interference,electrical insulation,corrosion resistance,low loss,small volume,high precision,etc.it has gradually replaced the traditional electrical sensor in the fields of petroleum industry,aviation industry,daily life application,etc.Optical fiber sensor based on Mach Zehnder interferometer is the most common.In this paper,several kinds of fiber sensors based on the principle of Mach Zehnder interferometer are fabricated by using multi-functional taper melting machine,multi-core fiber splicing,femtosecond laser and other instruments.The main research contents include:1.First of all,we introduce the development of optical fiber sensor and the basic introduction of optical fiber sensor.Then we introduce the purpose and significance of the research on Mach Zehnder interferometer,introduce the basic structure and type of this kind of sensor,and introduce the application of this kind of sensor.Then we make statistics of the research status of this kind of sensor at home and abroad,and understand that this kind of sensor is more Advantages and disadvantages of foreign countries.At last,three kinds of sensors based on the principle of Mach Zehnder interferometer are introduced.The measurement method and sensing principle of each sensor are introduced,and the physical parameters such as temperature and refractive index are measured and compared.2.A high sensitivity fiber optic sensor for measuring temperature and refractive index was developed by using femtosecond laser.Firstly,the multimode fiber and the single-mode fiber are spliced together,then the femtosecond laser is used to drill the multimode fiber,and a complex Mach Zehnder interferometer is formed by splicing the fiber micropores and the fibers with different core diameters.The high temperature and refractive index parameters of the fiber are measured by the prepared interferometer.The high temperature sensitivity is 18.55pm/?,and the refractiveindex is sensitive Degree up to-155.2d B/RIU.3.A kind of tapered fiber structure is formed by micro drawing ordinary single-mode fiber with multi-functional melting taper machine.The length of tapered fiber is 2mm and the minimum diameter of waist is 60 ?m.The sensitivity of thesensor is 260.5nm/RIU.4.A new Mach Zehnder interferometer optical fiber sensor is proposed,which is composed of single-mode,multi-mode,multi-core,multi-mode and single-mode.The stable transmission interference pattern is formed by coupling light in single-mode fiber,multi-core fiber and multi-mode fiber,and the refractive index is measured by the linear change of the transmission pattern with the environmental refractive index.By measuring the refractive index of Na Cl solution,the sensitivity of the sensor is4.997 d B/RIU.