Numerical dark field illumination applied to experimental digital lensless holographic microscopy for reconstructions with enhanced contrast.

The implementation of a numerical dark field illumination to obtain reconstructions with enhanced contrast in digital lensless holographic (DLHM) microscopy is presented. In this proposal, an opaque circular stop is numerically inserted in the light path between the sample and hologram plane. The contrast of the reconstructed holograms is increased at least 46% in comparison with that obtained by the regular reconstruction methods. This proposal has been validated using experimental holograms of a paramecium in water and a section of the head of a Drosophila melanogaster fly recorded in DLHM.