Abstract
Digital speckle pattern photography is applied to the measurement of light deflection profiles of inhomogeneous transparent objects by transmission of a He–Ne laser speckle field through the object. The speckles are recorded with a CCD camera, and the local displacements are evaluated by comparison of the deflected speckle field with the undeflected field by a digital cross-correlation technique. In this way a complete two-dimensional deflection field can be obtained from a single pair of CCD records. The basic technique and two experimental setups suitable for objects with a size larger than that of the CCD chip are described. These novel techniques are applied to determine profiles of the refractive index of a free-burning arc in air. In addition, a cinematographic setup is described, which allows the investigation of transient objects by means of a video tape recorder.
© 1997 Optical Society of America
Full Article | PDF ArticleMore Like This
M. Sjödahl
Appl. Opt. 36(13) 2875-2885 (1997)
M. Sjödahl and H. O. Saldner
Appl. Opt. 36(16) 3645-3648 (1997)
M. Buendía, R. Cibrián, R. Salvador, C. Roldán, and J. M. Iñesta
Appl. Opt. 36(11) 2395-2400 (1997)