METHOD AND DEVICE FOR THE OPTICAL NON-CONTACT OSCILLATION MEASUREMENT OF AN OSCILLATING OBJECT

摘要

The invention relates to a device for the optical non-contact oscillation measurement of an oscillating object, comprising a laser Doppler vibrometer that has a laser (1) as the light source for a laser beam, a first beam splitter assembly (S1) for splitting the laser beam into a measuring beam (2) and a reference beam (3), a means (4) for shifting the frequency of the reference beam (3) or of the measuring beam (2) in a defined manner, a second beam splitter assembly (S2, S3) by means of which the measuring beam (2) back-scattered by the oscillating object (6) is merged with the reference beam (3) and superimposed on the same, and a detector (5) for receiving the superimposed measuring and reference beam (7) and for generating a measurement signal, wherein the laser (1) is provided with a polarization filter arranged inside the optical resonator of the laser and the frequency of the dominating mode can be kept constant by a control to the beat signal.