Abstract
In our earlier work, a multipoint diffraction strain sensor using a microlens array was developed for measurement of whole-field strains. The method is extended to a system with variable sensitivity and measurement range. In the present system, two collimated laser beams, in diameter, symmetrically strike the grating attached to the specimen surface at prescribed angles. The diffracted wavefronts, magnified by a microscope objective, are sampled by a lenslet array with each microlens acting as an individual strain sensor. In-plane strain components over the full field can be measured by what is to our knowledge a new sensor with variable sensitivity by changing the distance from the microscope objective to the microlens array. Both a theoretical explanation and experimental verification are provided.
© 2007 Optical Society of America
Full Article | PDF ArticleMore Like This
Anand Asundi and Bing Zhao
Appl. Opt. 38(34) 7167-7169 (1999)
Matias R. Viotti, Armando Albertazzi G., Jr., and Walter A. Kapp
Appl. Opt. 50(7) 1014-1022 (2011)
Per Synnergren and Mikael Sjödahl
Appl. Opt. 41(7) 1323-1329 (2002)