| Popis: |
Characterizing tracer micro particles in fluids is of a great challenge for digital holographic techniques. The real locations and the number of these particles are the main parameters in such studies. For the first parameter, holographic techniques are very useful, unfortunately, they suffer from the large depth of focus which increases the location uncertainty of the particles. To minimize this uncertainty, we proposed a two orthogonal views system which, from our point of view, makes the location more precise by crossing the two views data in the reconstruction process. For the second parameter (particle number), off-axis configuration is recognized to be more convenient for large particle numbers than the in line configuration. In order to validate the effectiveness of the off-axis configuration in terms of number of tracer particles, we carry out some experiments. The number of particle was increased continuously after each recording. We have also tried to keep unchanged the experiment conditions during all the recording process. In the present work, we describe the manner in which the experiments were conducted and the obtained results in term of diffraction efficiency of the reconstructed holograms. |
