Research On Hollow Core Fiber Based Fabry Perot Sensor

Today,the world's military powers of main battle tanks,most of the ceramic composite armor to resist projectile attacks,in the study of ceramic composite armor against projectile on the penetration mechanism and experiment,to learn the dynamic characteristics of anti penetration penetration of ceramic composite materials,composite materials in the understanding of ammunitions penetrating moment of the whole stress wave field,including some key points of stress wave rise time and duration,the peak stress and falling time,is very important for the designer,and projectile penetrating the stress wave field with high strength,high temporal and high spatial resolution ratio gradient field,the impact of instant explosion due to energy transient effect easy to produce strong ionization interference,optical fiber F-P cavity strain sensor all silica structure is expected to solve this problem.Therefore,this paper focuses on the study and implementation of the hollow core optical fiber Fabry-Perot strain sensor,optical fiber sensors intrinsically anti electromagnetic interference is especially suitable for projectile impact or explosion stress wave measurement,optical fiber F-P cavity length small(typical values of up to several tens of micrometers),can achieve high temporal and high spatial resolution measurements and compared to in etching method,making it to the unity and the reliability is high,its process is relatively simple,and etching method because the corrosion process is difficult to control,so it is difficult to ensure that the sensor uniformity and repeatability.Higher compared to coating for making the Fabry Perot pressure sensor,it not only guarantees the accuracy and sensitivity,stronger mechanical strength,can withstand the pressure range,process is relatively simple.The main work of this paper is as follows:Sensor was fabricated by the general steps are introduced,and the discharge principle of welding machine is analyzed,by theory and experiment that welding optimization of hollow fiber and single-mode fiber production parameters,namely discharge current intensity between 35 and 45,hollow fiber and single-mode optical fiber fusion junction and fiber end is smooth,reflected power loss is small are described in detail.Under a microscope,the cutting hollow fiber on the steps of the process,by comparing the different cavity length sensor interference fringe reflection spectrum was obtained by the optimized parameters can produce a shorter length,the visibility of fringe pattern is very high,smoothness is very excellent F-P interferometric sensors.Fabry Perot strain sensor for strain and temperature characteristics of experimental analysis.The results show that,the sensitivity of the sensor to 3.133Deg/?? and linearity 0.9996,repeatability index is 0.21%,to adapt to the outside world has a high response;and the interference fringe peak phase with the temperature changes very little,in 95 ?,the phase change only 0.4 degrees,indicating that the sensor is not sensitive to temperature cross.Based on the production method of hollow center optical fiber Fabry Perot pressure sensor and the basic principle,then the analysis the performance parameters of the sensor,results show that,at last,the paper briefly introduces the application prospect of Fabry Perot pressure sensor are introduced.