High-resolution electric speckle pattern interferometry by using only two speckle patterns

Electronic speckle pattern interferometry is a useful deformation measurement method. In this paper, new method that can measure the deformation by limited information without using much higher speed cameras is proposed. The optical system that can record some spatial information into each speckle of speckle pattern is set up by using basic characteristics of speckle that has never been used before. In experimental results, it is confirmed that the out-of-plane deformation measurement by using only two speckle patterns before and after the deformation can be precisely performed by this method and that the resolution-power of new method is almost equivalent to that of ordinary method.