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.

Wavefronts matching: a novel paradigm for three-dimensional holographic particle tracking

Abstract: Digital Holography (DH) in microscopy allows to retrieve in an accurate way the spatial coordinates of multiple moving particles, performing 3D tracking of the sample in the entire field of view. In particular, a posteriori quantitative multifocus phase-contrast imaging, suitable for 3D tracking of micro-objects, is one of the main features of the holographic approach. However, classical methods need to decouple amplitude and phase contributions of the reconstructed complex wavefronts to calculate target positions in 3D, due to the fact that the lateral displacements can be calculated only after refocusing step. In order to overcome this limitation, recently, a novel method of the simultaneous calculation of both axial and lateral coordinates of moving particles has been proposed. This is based on the novel concept of wavefronts matching, i.e. the 3D positions of micro-object, moving in 3D volume, are obtained by aligning wo subsequent holographic complex reconstructions, calculated at the same distance. We test this approach in different experimental conditions in order to highlight its effectiveness in bio-microfluidic applications.

Respiratory Aware Routing for Cyclists

Abstract: Cyclists travelling in urban areas are particularly at risk of harm from these emissions due to their increased breathing rate and proximity to vehicles. Our objective in this paper is to present a framework for routing of cyclists to mitigate the effects of pollution. However, in contrast to classical exposure based studies that are based on am-bient pollution levels and travel times, the work presented here is also based on individualised fitness and physiological parameters. A key finding of this work is that statistical analysis of random synthetic commutes in London demonstrate that the impact of street-level pollution is significantly higher for less fit individuals. Further, our work suggests that pollution inhalation highly-polluted areas may be modulated through an increase of cycle velocity. These findings establish personalised travel optimisation as an effective method of reducing pollution risk, improving the net benefits of active commuting.

Pyro-EHD 3D printing at microscale

Abstract: The term “pyro-electrohydrodynamic printing” expresses the ability of working on fluids (liquid and/or polymer) exploiting the pyro-electric effect activated onto a ferroelectric crystal in an electrode-less configuration. The simplicity of the method proposed, associated with the flexibility of the process for fabricating 3D polymer microstructures, demonstrates its great potentiality exploitable in many fields of additive manufacturing, from optics to biosensing.

Investigation of photorefractive spatial bright soliton in lithium niobate by interferometric technique

Abstract: Photorefractive spatial bright soliton in lithium niobate is investigated using Mach-Zehnder interferometric technique. A numerical simulation of the soliton formation is also performed using a one-dimensional beam propagation method. The intensity and phase map obtained in this way is compared with the experimental results. Digital holograms were electronically recorded during the soliton formation.

Color holograms synthesis framework for three-dimensional scene reconstruction

Abstract: We propose a complete framework for the synthesis of 3D holographic scene, combining multiple color holograms of different objects by applying adaptive transformations. In particular, it has been demonstrated that affine transformation of digital holograms can be employed to defocus and chromatic aberrations. By combining these two features we are able to synthesize a color scene where multiple objects are jointly multiplexed. Since holograms transformation could be introduce artifacts in the holographic reconstructions, principally related to the presence of speckle noise, we also implement a denoising step where the Bi-dimensional Empirical Mode Decomposition (BEMD) algorithm is employed. We test the proposed framework in two different scenario, i.e. by coding color three-dimensional scenes and joining different objects that are (i) experimentally recorded and (ii) obtained as color computer generated holograms (CCGH).

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.