Speckle interferometry with temporal phase evaluation: Optimization of imaging aperture for in-plane displacement
Abstract:Recently a new method to measure object shape and deformation using temporal evolution of speckles in speckle interferometry was reported. The principle behind the method is that certain parameter sensitive to shape or deformation is changed continuously and the fluctuations in the intensity of the speckles are recorded in a large number of frames. The phase data for the whole object deformation is then retrieved by inverse Fourier transformation of a filtered spectrum obtained by Fourier transformation of the signal. In this paper a theoretical evaluation of the amplitude of the signal for inplane sensitive interferometer that uses dual beam illumination is presented. It is shown that signal to noise ratio is better when the speckle size is smaller than the pixel size contrary to the normal assumption that the speckle size be matched to the pixel size.
Document Type: Original Article
Affiliations: Department of Physics and Applied Optics, Rose-Hulman Institute of Technology, 5500 Wabash Avenue, Terre Haute, IN 47802, USA
Publication date: November 1, 2001