Pseudophase information from the complex analytic signal of speckle fields and its applications. Part I: microdisplacement observation based on phase-only correlation in the signal domain

Appl Opt. 2005 Aug 10;44(23):4909-15. doi: 10.1364/ao.44.004909.

Abstract

As an alternative to the intensity correlation used in conventional speckle metrology, we propose a new technique for displacement observation that is based on spatial-signal-domain phase-only correlation and that makes use of the pseudophase of the complex analytic signal generated from a Hilbert-filtered speckle pattern. Experimental results are presented that demonstrate the validity and the advantage of the proposed signal-domain phase-only correlation technique over both the conventional intensity correlation technique and the spatial-frequency-domain phase-only correlation technique.