スペックル干渉法を用いた微小領域のひずみ測定

抄録

Conditions for applying speckle interferometry to measure displacements under an optical microscope are investigated. Laser speckle images are captured under x10 optical magnification with a laser having a wavelength of 533 nm. Optimizations of the surface roughness of an object and the position correction of the speckle pattern in captured images are performed. As a result, about a half of the laser wavelength in the arithmetic average roughness is required for obtaining good speckle pattern images. Effective images for obtaining the position correction amounts using digital image correlation method can be captured with white light illumination on the surface having that roughness. A phase map can be obtained using the optimal speckle images with the position correction.