title: On-speckle suppression in IR digital holography.
abstract: Long-IR wavelength is the best option for capturing digital holograms of large-size, real-world objects. However, the coherent noise level in a long-IR hologram is by far larger than that of a visible wavelength recording, thus resulting in a poor quality of both numerical and optical reconstructions. In this Letter, we show how such coherent noise can be efficiently suppressed by employing an optical scanning multi-look approach, in combination with 3D block matching numerical filtering. Results demonstrate the possibility to obtain near noise-free numerical reconstructions of IR digital holograms of large-size objects, while preserving resolution. We applied this method to the holograms of a rotating statuette. It will be shown that a remarkable contrast enhancement is achievable along with the recovery of object details that otherwise would be lost because of large speckle grains intrinsically due to the source coherence.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Bianco
authors.forename: Pasquale
authors.initials: P
authors.lastname: Memmolo
authors.forename: Melania
authors.initials: M
authors.lastname: Paturzo
authors.forename: Pietro
authors.initials: P
authors.lastname: Ferraro