Digital in-line holography: influence of the reconstruction function on the axial profile of a reconstructed particle image

The numerical reconstruction of an in-line digital hologram is a critical point in digital holographic particle image velocimetry. In particular, the shape of the axial profile of the reconstructed particles plays an important role in depth recovery. We show that this profile presents some oscillations when reconstructing by convolution with the Fresnel function. A window can be introduced in the expression of the reconstruction function in order to control these oscillations. The effects of this windowing are discussed and a criterion for the choice of window is given. The method is then illustrated by the processing of a digital hologram of Lycopode particles.