Study On Technique Of Vibration Measurement Using Laser Doppler

This paper researches on the vibration caused by acoustic signal with small amplitude, which is also susceptible to environment interference, and the authors select laser doppler technique to detect the remote and faint signal.Specific content is introduced as follows:First, the basic theories of vibration detection of the laser doppler heterodyne interference, and three methods of heterodyne interferometer are introduced. By comparative analysis, PZT for phase modulation is selected.Second, the main devices of the design of PZT phase modulation of heterodyne vibration detection is analyzed, simulated and contrasted to the experiments from the factors of the system components, the SNR of the heterodyne detection, detection efficiency, etc.Finally, the authors joint experimental devices regularly and test it, and the test results prove that this optical system can realize the long distance, high precision, non-contact and nano-level vibration detection of the acoustic signal, and it can overcome the interference of environmental. However, the stability of the system performance to be further improved.