Research On Sensing Characteristics Of Fabry-pérot Interferometer Based On Composite Cavity Fiber And Demodulation Software Development

With the continuous development of optical fiber technology,optical fiber sensing technology has also seen great advancement.Optical fiber sensing technology is widely used in structure building,aerospace,geological exploration,petroleum exploitation,engineering maintenance and so on thanks to its strong anti-interference ability,flexible and diverse structures and feasibility to measure many physical quantities.Because the optical fiber sensor modulates the signal to the parameters such as the wavelength,phase,intensity and polarization of the transmitted beam,the demodulation of the signal is very important.The construction of the demodulation system and the fabrication of the sensor structure also affect the measurement of the physical quantity of the sensor.In this paper,a kind of Composite Cavity Fiber Fabry-Pérot Interferometer Sensor is proposed.The temperature sensing characteristics of the sensor are studied,the demodulation system of the sensor is constructed,and the demodulation software is compiled.The research contents of this paper are as follows:Firstly,the development,classification and application of optical fiber sensors are described.This paper introduces the research status of Fabry-Pérot Interferometer with composite cavity at home and abroad,describes and compares several fabrication methods of optical fiber Fabry-Pérot Interferometer,and analyzes the development of demodulation technology at present,and expounds the Fabry-Pérot Interferometer with composite cavity theoretically regarding the basic principles of the Fabry-Pérot Interferometer and its temperature sensing principle.Secondly,the demodulation system of demodulation sensor is constructed.The demodulation system is constructed by using tunable semiconductor scanning laser as signal source.This thesis also completes the serial communication between single chip computer and host computer.After the uploaded data is collected by Labview,the image of light intensity varying with wavelength is drawn.The program of simulation,peak seeking algorithm and temperature display is completed as well.Finally,a fabrication method of Fabry-Pérot Interferometer with composite cavity is proposed.This paper fabricates three kinds of composite cavity optical fiber Fabry-Pérot Interferometers with different sizes,analyzes the interferometric spectral lines in frequency domain,and experimentally tests the temperature sensing characteristics of the probe.Besides,this paper also analyzes the relationship between the interferometric spectral lines and the size of the sensor and compares the temperature sensitivity of three different-sized sensors.The maximum temperature sensitivity was 14.6pm/? in the range from 100? to 600?...