Three-Dimensional Shape Measurement Beyond Diffraction Limit for Measurement of Dynamic Events

Speckle interferometry is one of the important measurement methods of deformation on an object with rough surfaces. In this paper, a method which can be applied to a three-dimensional (3-D) shape measurement for dynamic events is proposed. In the method, the differential coefficient distribution of the shape of such an object is detected by giving a known lateral shift in the computer memory in order to analyze using one-shot speckle pattern. The 3-D shape can be reconstructed by integrating the differential coefficient distribution. The method is also applied to the 3-D shape measurement of superfine structure beyond the diffraction limit. Furthermore, the influence of magnitude of lateral shift on shape is discussed.