摘要 |
Method and system for measuring vibration in two or three directions in objects (12) by using three illumination light beams (11A-C) for measurement of in-plane vibrations in two directions, where one of the three illumination light beams (11A-C) is common for the two in-plane measurements, and where the three illumination light beams (11A-C) are configured to provide free space at one side of the object (12) for easier access to the object. The method and system is further arranged for using two illumination light beams (30A-B) for measuring vibrations in the object (12) in a third direction, which third direction is out-of-plane direction, where one illumination light beam (30A) is illuminating the object (12) through an imaging objective (16) and one illumination light beam (30B) is used as reference beam. |