Optical arrangement for measuring the vibrations of an object having a reflecting surface

摘要

The invention relates to an optical arrangement for measuring vibration amplitudes of an object. Two (or three) measuring beams (f1, f2, f3) are directed onto a point P of the object. The beam f'3 resulting from the interference (or instances of interference) and modulated by the vibration is intercepted by the detector (8). One or two components of the vibration in the tangential plane are determined from this. In addition, the beam f1 is directed onto the object at a point P and, after diffusion, combined with the reference beam fr in order to realise an instance of interference. This combined signal f'r is detected by the detector (10). The component of the vibration in the direction of the normal is determined from this.