Author
Giovanni Pierattini
Other affiliations: Olivetti
Bio: Giovanni Pierattini is an academic researcher from ARCO. The author has contributed to research in topics: Digital holography & Holography. The author has an hindex of 25, co-authored 128 publications receiving 3222 citations. Previous affiliations of Giovanni Pierattini include Olivetti.
Papers published on a yearly basis
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ARCO1
TL;DR: In this paper, a mathematical model for the computation of intensity of radiation in biological tissues irradiated by laser is presented, where the time-independent transport radiative equation is solved in terms of a Neumann series, each term of the series associated with a different order of magnitude of the internal scattering effect.
Abstract: A mathematical model is presented for the computation of intensity of radiation in biological tissues irradiated by laser. The time-independent transport radiative equation is solved in terms of a Neumann series. Each term of the series is associated with a different order of magnitude of the internal-scattering effect. The importance of these effects has been recognized during the irradiation by ion-argon and ND: YAG laser used as coagulting or cutting instruments in surgery applications. Agreement is found with the single-scattering picture.
12 Jun 2005
TL;DR: In this paper, a technique for achieving double face, sub-micron and 2D reversed domain patterns in congruent r-cut LN crystals is proposed, based on resist patterning the samples by interference photolithography followed by an electric field overpoling process.
Abstract: In this work, a technique for achieving double face, sub-micron and 2-D reversed domain patterns is proposed, in congruent r-cut LN crystals. This technique is based on resist patterning the samples by interference photolithography followed by an electric field overpoling process.
13 Jun 2005
TL;DR: In this article, a two-stage method for direct perfect superimposition and comparison of Fresnel transform reconstructions of digital holograms recorded at different wavelengths is proposed and demonstrated.
Abstract: A two stage method for allowing direct perfect superimposition and comparison of Fresnel-transform reconstructions of digital holograms recorded at different wavelengths is proposed and demonstrated. The method allows to adjust the size of the reconstruction pixel by varying the reconstruction distance of the first stage. Demonstration is given by superimposing in focus numerical reconstructions of holograms recorded at different wavelengths. The method can be potentially very useful for real-time monitoring in biological processes.
22 Jun 2005
TL;DR: In this paper, a brief introduction on the digital holographic microscope is given, reporting the numerical approach utilized to reduce aberrations, unwrap phase errors and defocusing of the reconstructed images.
Abstract: Digital holography is a valid instrument for characterization of micro-electro-mechanical systems (MEMS) with an high resolution and accuracy. In the this paper a brief introduction on the digital holographic microscope will be given, reporting the numerical approach utilized to reduce aberrations, unwrapping phase errors and defocusing of the reconstructed images. Moreover, we present the experimental results on the dynamic characterization of two macrostructured devices. In particular, a dynamic characterization of a micromechanical shunt switch in coplanar waveguide configuration, for microwave application, and a MEMS gas sensor, based on a Pt heater resistor on a Si/sub 3/N/sub 4/ membrane, has been analyzed.
TL;DR: In this paper, an optical heterodyne polarization interferometer is described that can be efficiently used for the precision measurement of the phase shift induced by polarizing optical devices, which can be used to measure the change with wavelength of a quarter-wave plate's retardation.
Abstract: An optical heterodyne polarization interferometer is described that can be efficiently used for the precision measurement of the phase shift induced by polarizing optical devices. This technique is used to measure the change with wavelength of a quarter-wave plate's retardation.
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Journal Article•
TL;DR: In this article, a fast Fourier transform method of topography and interferometry is proposed to discriminate between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour generation techniques.
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.
3,742 citations
TL;DR: In this article, the physical mechanisms and the main experimental parameters involved in femtosecond laser micromachining of transparent materials, and important emerging applications of the technology are described.
Abstract: Femtosecond laser micromachining can be used either to remove materials or to change a material's properties, and can be applied to both absorptive and transparent substances. Over the past decade, this technique has been used in a broad range of applications, from waveguide fabrication to cell ablation. This review describes the physical mechanisms and the main experimental parameters involved in the femtosecond laser micromachining of transparent materials, and important emerging applications of the technology. Interactions between laser and matter are fascinating and have found a wide range of applications. This article gives an overview of the fundamental physical mechanisms in the processing of transparent materials using ultrafast lasers, as well as important emerging applications of the technology.
2,533 citations
TL;DR: The principles and major applications of digital recording and numerical reconstruction of holograms (digital holography) are described, which are applied to measure shape and surface deformation of opaque bodies and refractive index fields within transparent media.
Abstract: This article describes the principles and major applications of digital recording and numerical reconstruction of holograms (digital holography). Digital holography became feasible since charged coupled devices (CCDs) with suitable numbers and sizes of pixels and computers with sufficient speed became available. The Fresnel or Fourier holograms are recorded directly by the CCD and stored digitally. No film material involving wet-chemical or other processing is necessary. The reconstruction of the wavefield, which is done optically by illumination of a hologram, is performed by numerical methods. The numerical reconstruction process is based on the Fresnel–Kirchhoff integral, which describes the diffraction of the reconstructing wave at the micro-structure of the hologram. In the numerical reconstruction process not only the intensity, but also the phase distribution of the stored wavefield can be computed from the digital hologram. This offers new possibilities for a variety of applications. Digital holography is applied to measure shape and surface deformation of opaque bodies and refractive index fields within transparent media. Further applications are imaging and microscopy, where it is advantageous to refocus the area under investigation by numerical methods.
1,171 citations
TL;DR: This paper presents a meta-analyses of Fourier-Transform Profilometry and its applications in 3-D Shape Measurement and Surface Profile Measurement for Structured Light Pattern and 4-Core Optical-Fiber.
1,110 citations
TL;DR: Digital holography is an emerging field of new paradigm in general imaging applications as discussed by the authors, and a review of a subset of the research and development activities in digital holographic microscopy techniques and applications is presented.
Abstract: Digital holography is an emerging field of new paradigm in general imaging applications. We present a review of a subset of the research and development activities in digital holography, with emphasis on microscopy techniques and applications. First, the basic results from the general theory of holography, based on the scalar diffraction theory, are summarized, and a general description of the digital holographic microscopy process is given, including quantitative phase microscopy. Several numerical diffraction methods are described and compared, and a number of representative configurations used in digital holography are described, including off-axis Fresnel, Fourier, image plane, in-line, Gabor, and phase-shifting digital holographies. Then we survey numerical techniques that give rise to unique capabilities of digital holography, including suppression of dc and twin image terms, pixel resolution control, optical phase unwrapping, aberration compensation, and others. A survey is also given of representative application areas, including biomedical microscopy, particle field holography, micrometrology, and holographic tomography, as well as some of the special techniques, such as holography of total internal reflection, optical scanning holography, digital interference holography, and heterodyne holography. The review is intended for students and new researchers interested in developing new techniques and exploring new applications of digital holography.
672 citations