Pietro Ferraro

Bio: Pietro Ferraro is an academic researcher from National Research Council. The author has contributed to research in topics: Digital holography & Holography. The author has an hindex of 61, co-authored 653 publications receiving 12666 citations. Previous affiliations of Pietro Ferraro include Aeritalia & Centre national de la recherche scientifique.

What breaks the shadow of the tube

Abstract: When an object is partially immersed and inclined in the water, the shadow of the object seen on the bottom of the container appears to be broken in two distinct parts or blown up in correspondence of the immersion line. The effect is very simple to show and observations and discussions could be developed in the classroom about surface tensions, wettability, and optics.

Automatic removal of phase aberration in holographic microscopy for drug sensitivity detection of ovarian cancer cells

Abstract: Real-time and long-term monitoring of the morphological changes of cells in biomedical science is highly desired Quantitative phase imaging (QPI) obtained by various interferometric methods is the ideal tool for monitoring such processes as it allows to get quantitative information and thus assessing the right response on cell behaviors Among QPI, digital holography (DH) in microscope configuration is a powerful tool as it is tolerant versus defocusing and for this reason is able to compensate for eventual defocusing effect during long time-lapse recording Moreover, DH dynamic phase imaging for biological specimens has several advantages, namely non-invasive, label-free, and high-resolution However, in DH, one of the main limitations is due to the need compensate aberrations due to the optical components in the object beam In fact, the image of the object is inevitably embedded in aberrations due to the microscope objective (MO) and other optical components in the optical setup Here, we propose an automatic and robust phase aberration compensation method based on a synthetic difference (SD) image process The method is able to detect automatically object-free regions From such regions, hologram’s aberrations can be accurately evaluated and cleaned up in the final QPI maps Thanks to our method, temporal evolutions of cell morphological parameters were quantitatively analyzed, hence helping in studying the drug sensitivity of ovarian cancer cells The experimental results demonstrated that the proposed method could robustly separate the object-free region from the distorted phase image and automatically compensate the total aberrations without any manual interventions, extra components, prior knowledge of the object, and optical setup

High Resolution X-Ray Characterization of Sub-Micron Periodic Domain Structures in Lithium Niobate Crystals

Abstract: The High Resolution X-Ray Diffraction technique in the reciprocal space mapping mode is exploited to study sub-micron periodic domain structures in lithium niobate crystals. Periodic satellite structure were detected around the reciprocal lattice points which carry information on the domain period and shape and also on the presence of lattice deformations. Moreover a pronounced diffuse scattering peak was observed, indicating the presence of a random displacement field possibly associated to the presence of randomly distributed structural defect.

Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry

Abstract: A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Fiber grating sensors

Abstract: We review the recent developments in the area of optical fiber grating sensors, including quasi-distributed strain sensing using Bragg gratings, systems based on chirped gratings, intragrating sensing concepts, long period-based grating sensors, fiber grating laser-based systems, and interferometric sensor systems based on grating reflectors.