| The fiber Doppler velocimeter is developed on the basis of photonic Doppler effect and heterodyne technique,which is assembled using off-the-shelf components developed for the optical communication industry.Compared with the traditional laser Doppler velocimeter(LDV),because of using off-the-shelf components developed for the optical communication industry,the fiber Doppler velocimeter is compact,cheap and convenient. The fiber Doppler velocimetry developed from 2000,studied by American,Frenchmen and Chinese,has been applied in detonation physics.In this paper,two different structure of the Doppler velocimeters are assembled and improved.Substituting GRIN lens for tradition lens makes coupling probe with fiber easy, adding EDFA and filter to the fiber Doppler velocimeter increases the depth modulation of interference greatly.Data processing methods for the Doppler velocimeters are studied and processing errors are shown.Experimentally,in order to extend the application of the fiber Doppler velocimeter,besides the denotation velocity is measured,rotating speed and libration of piezoelectric ceramic are measured.The main research works and results are as follows:1 The history and status of laser interferometry for measuring velocities are expounded. A conclusion can be made that the fiber Doppler velocimeter is promising.2 The principle of the fiber Doppler velocimetry is presented and the feasibility for the velocity measurement by the single mode fiber Doppler velocimeter is proved.3 Two different structure of the fiber Doppler velocimeters are assembled using off-the-shelf components developed for the optical communication industry,which are the fiber displacement interferometer and the the direction-judgable fiber displacement interferometer.4 Data processing methods for the fiber Doppler velocimeters are studied.5 The experiments are conducted to study two different velocimeters,the advantage and disadvantage of two different velocimeters are discussed. |
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