Fiber Acceleration Sensing System

This thesis describes a all fiber optic accelerometer based on T-G double beam interferometer,the whole system include a coherent source whose wavelength is 1310nm, a flexural optic fiber disk act as sensing unit, photodetector,piezoelectric ceramic act as a phase modulator and signal processing circuit.The all fiber optic accelerometer described in the paper has many desirable engineering features which include: broad frequency response;high sensitivity to measurands; antielectromagnetic interference and small size.At the first part of this thesis,the global development of the optic fiber accelerometer is explained,it is proved that optic fiber sensor has been a hot study focus in many scientists's eyes,and different methods of optic fiber sensor have been discussed and compared.Based theory of the fiber optic accelerometer is presented in details,According to the the principle of phase modulation a new experimental scheme is described.In this scheme,a center supported flexural disk design is chosen as the sensing mechanism,the fiber of the interferometer is attached on each side of the flexural disk,such design is helpful to the desirable features such as high acceleration sensitivity and immunity to extraneous measurands.In the following parts of this paper,more specific analysis has been presented about how to design the parameter of the optical system,how to choose the photoconducting device and how to control the signal and noise.The equipment of the experiment are described in the last parts of this paper,and some useful results are abtained.