Abstract
Two new techniques making use of the scattered-light speckle pattern have been developed which yield the displacements on an arbitrary interior plane of a 3-D body. When a sheet of coherent light passes through a transparent 3-D body, a small fraction is scattered. This scattered light produces a speckle pattern in an imaging system. By recording two superimposed images of this speckle pattern, one before and one after body deformation, the displacements on the interior illuminated plane can be found. The technique of scattered-light photography uses a single illuminating beam and is sensitive to displacements greater than one speckle diameter, approximately 3 μm. Scattered-light speckle interferometry uses two illuminating beams and is sensitive to displacements greater than one half the wavelength of light being used, approximately 0.2 μm. With both techniques, the double-exposed speckle photograph is optically processed to yield displacement information. With both techniques, the maximum displacement measurable is limited by correlation requirements between the two speckle patterns. Experimental results are presented demonstrating the two new techniques.
Similar content being viewed by others
References
Leendertz, J. A., “Interferometric Displacement Measurement on Scattering Surfaces Utilizing Speckle Effect,”J. Phys. E. (Sc. Inst.),3,214–218 (1970).
Archbold, E., Burch, J. M., Ennos, A. E., “Recording of In-Plane Surface Displacement by Double Exposure Speckle Photography,”Optica Acta,17,883–898 (1970).
Butters, J. N. andLeendertz, J. A., “A Double-Exposure Technique for Speckle Pattern Interferometry,”J. Phys. E. (Sc. Instr.) 4,277–279 (1971).
Archbold, E. andEnnos, A. E., “Displacement Measurement From Double-Exposure Laser Photographs,”Optica Acta,19,253–271 (1972).
Hung, Y. Y. andHovanesian, J. D., “Full-field Surface-strain and Displacement Analysis of Three-dimensional Objects by Speckle Interferometry,”Experimental Mechanics,12 (10),454–460 (1972).
Duffy, D. E., “Measurement of Surface Displacement Normal to the Line of Sight,”Experimental Mechanics,14 (9),378–384 (1974).
Archbold, E. andEnnos, A. E., “Applications of Holography and Speckle Photography to the Measurement of Displacement and Strain,”J. Strain Analysis,9,10–16 (1974).
Luxmoore, A. R., Amin, F. A. A., Evans, W. T., “In-Plane Strain Measurement by Speckle Photography—A Practical Assessment of the Use of Young's Fringes,”J. Strain Analysis,9,26–35 (1974).
Denby, D. andLeendertz, J. A., “Plane Surface Strain Examination by Speckle-Pattern Interferometry Using Electronic Processing,”J. Strain Analysis,9,17–25 (1974).
Burch, J. M. andTokarski, “Production of Multiple Beam Fringes from Photographic Scatterers,”Optica Acta,15,101–111 (1968).
Hung, R. E., Rowlands, R. E., andDaniel, I. M., “Speckle-Shearing Interferometric Technique—a Full-Field Strain Gauge,”Ap. Opt.,14,618–622 (1975).
Author information
Authors and Affiliations
Additional information
Investigation was funded by the National Science Foundation, Grant # GK-40012.
Rights and permissions
About this article
Cite this article
Barker, D.B., Fourney, M.E. Displacement measurements in the interior of 3-D bodies using scattered-light speckle patterns. Experimental Mechanics 16, 209–214 (1976). https://doi.org/10.1007/BF02329270
Issue Date:
DOI: https://doi.org/10.1007/BF02329270