Recently we proposed an alternative method of displacement analysis in vortex
metrology, based on the application of the Fourier optics techniques, that is
suitable for an intermediate range of displacement measurements ranging below
the resolution of speckle photography and above that of the conventional vortex
metrology. However, for smaller displacements, we introduce an approach to
perform the Fourier analysis from vortex networks. In this work, we present an
enhanced method for measuring uniform in-plane displacements, taking advantage
of the capability of determining the subpixel locations of vortices and having
the ability to track the homologous vortices onto a plane. It is shown that
high-quality fringe systems can be synthesized and analyzed to accurately
measure in an extended range of displacements and for highly decorrelated
speckle patterns. Experimental results supporting the validity of the method are
presented and discussed.
© 2013 Optical Society of America
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