Abstract: A system is used to excite an object at a vibration frequency, in order to induce stationary or travelling waves having the vibration frequency on the surface of the object. An optical interferometer is configured to use optical interference to determine vibration amplitude and phase data of the stationary or travelling wave at each of a plurality of points on the surface, relative to a reference phase. A processing system is used to apply a spatial derivative filter to the vibration phase data, and the resulting spatial-derivative-of-phase data is processed to determine a property of the object, and is further processed to generate graphical-representation data for outputting on a display device.

Abstract: An optical interferometer (1) is used to determine information about the position, gradient or motion of a surface of an object (2) at each of a plurality of points on the surface. An image is projected onto the surface of the object (2), such that, for each of the plurality of points, the intensity or spectrum of the projected image at that point depends on the determined information about the position, gradient or motion of the surface at that point.

Abstract: An optical interferometer (1) is used to determine information about the position, gradient or motion of a surface of an object (2) at each of a plurality of points on the surface. An image is projected onto the surface of the object (2), such that, for each of the plurality of points, the intensity or spectrum of the projected image at that point depends on the determined information about the position, gradient or motion of the surface at that point.

Abstract: 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.

Abstract: A Method for measuring vibrations in small and microscopic objects is disclosed. The method includes the steps of vibrating the object at a frequency, illuminating the object with a light source which is phase modulated at the same frequency, collecting data from a detector array, operating an algorithm to calculate the size of interference modulation between the light waves, operating an algorithm based on multiple calculation of the modulation at different vibration phases between the excitation of the object on one hand, and the reference phase modulation on the other, and operating an algorithm based on use of the result from the calculation of the second modulation, calculating amplitude values and phase values for the vibration of the surface of the object.