Non-contact interferometric measurement of the vibrations parameters under diffuse light reflection

The interferometric technique based on laser autodyne interferometer has been applied for the digital measurement of periodic micromovements of a sample. The measured oscillation parameters are: the amplitude, the frequency and the real time monitoring of the form. of the micromovement. The technique does not critically to the adjustment of reflected beam on a sample and works with the diffuse light reflection. The frequency band is from several Hz up to 10(5) Hz and amplitudes range is from 1 mu m up to 1 mm. In case of harmonical oscillations the accuracy of measurement was obtained better than 2%. Theoretical and practical aspects of the performance measurement with laser autodyne are discussed.