Accuracy of Axial Localization of Particles from In-Line Hologram by Wavelet Transforms

Abstract

In the digital holography applied to particle localization, the depth of focus of the holographic process limits the axial resolution. The wavelet technique, based on the direct analysis of the particles hologram, makes it possible to find the axial location of the particles without going through the reconstruction process. The principle of this technique consists in the frequency analysis of the interference fringes of the particles hologram. In practice, it is found that the measurement accuracy of the local frequency also depends on the size of the particles, which affects the axial resolution. A numerical simulation study shows this phenomenon which resembles the effect of the depth of focus in the holographic reconstruction process.