Research And Design Of An Optical Fiber Acoustic Emission Sensor F-p

The Acoustic Emission(AE) signal is measured by piezoelectric ceramic transducer(PZT) now, which has several advantages such as lower cost and easier realization. The disadvantages of measuring AE signal by PZT are its susceptibility of electromagnetic disturbance and the difficulty of real-time measuring. On the other hand, the fiber sensor has many advantages such as high precision, immunity to electromagnetic interference, easily to realize distributive, real-time measurement, and so on. It is one of the most important research subjects all over the world. On the base of a general review of fiber AE development at home and abroad, a new idea of an Extrinsic F-P interferometer sensor is offered in this paper. Sensing principle, structure and sensing characteristics are studied. The main contents of this research are as follows:1. It presents the fiber Extrinsic F-P interferometer instrument for measuring AE signal. The principle for measuring AE signal is analyzed and the mathematical model of EFPI is deduced.2.The stabilization method of the dual-wavelength is proposed. The structural parameter of this system is designed by optimal design with MATLAB 6.The F-P cavity length, reflectance and wavelength are confirmed.3.This paper develops an EFPI AE measurement system anatomizing characteristics of every part such as source, fiber coupler, optics wavelength division multiplexer and light receiver.Theoretical analysis and experimental results indicate that the optical fiber Extrinsic F-P interferometer AE sensor has refined sensitivity and high resolution. It provides a brand-new and effective way to measure AE signal.In this paper, the research is sponsored by the Nature Science Foundation of China (50275125) and the Aero Science Foundation of China( 04153068).