We present a detailed investigation of digital speckle correlation to measure small changes in the microstructure of random rough surfaces. The corresponding alterations in the scattered-light field are recorded by an electronic camera with subsequent numerical correlation. Among the classical theoretical approaches to describe the scattering at random rough surfaces, the composite-roughness model is advanced to calculate the speckle correlation in terms of parameters of the changes in surface microstructure. For an experimental verification, surfaces with similar microstructure are fabricated with a photolithographic technique. They are employed for comparative measurements with high-resolution scanning force microscopy and for correlation measurements under variation of experimental parameters. A good agreement between theoretically predicted and experimental correlation data can be observed. The results allow a quantitative whole-field monitoring of surface processes by remote optical means.
© 2004 Optical Society of AmericaFull Article | PDF Article
OSA Recommended Articles
Appl. Opt. 42(34) 6783-6796 (2003)
J. Opt. Soc. Am. A 3(8) 1297-1304 (1986)
Thomas Fricke-Begemann, Gerd Gülker, Klaus D. Hinsch, and Karen Wolff
Appl. Opt. 38(28) 5948-5955 (1999)