Geometric micron-moire

A high spatial resolution and high-sensitivity geometric micron-moire metho d is presented. The method is based upon classical geometric moire method a nd microscopic principle, the frequency of the specimen and reference grati ngs used in this method can be higher than 1000 lines/mm. By a microscopic moire system, the high-frequency gratings could be magnified to a low-frequ ency level, so geometric moire patterns can be formed. Experiments show tha t both the spatial resolution and the sensitivity can reach or exceed micro n-level. (C) 1999 Elsevier Science Ltd. All rights reserved.