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Giuseppe Coppola

Bio: Giuseppe Coppola 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 40, co-authored 256 publications receiving 5489 citations. Previous affiliations of Giuseppe Coppola include Seconda Università degli Studi di Napoli & University of Naples Federico II.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the authors present the thermo-electro-optical analysis of an integrated waveguide-vanishing-based optical modulator based on the free carrier dispersion effect.
Abstract: Silicon is the most widely used material in the microelectronics industry and it is becoming more widespread in integrated optic and opto-electronic fields. We present the thermo-electro-optical analysis of an integrated waveguide-vanishing-based optical modulator based on the free carrier dispersion effect. This particular structure allows one to obtain a planar device, with an easier CMOS compatible microelectronic integration. The implantation processes have been carefully tuned in order to get higher doping uniformity and a sharp profile. The process-flow is defined using the 2D process simulation software ATHENA (SILVACO International). The 2D semiconductor device simulation package ATLAS (SILVACO International) has been employed to analyse the coupled electro-thermal behaviour of our modulator in static and dynamic conditions. The electrical section of the modulation acts as a lateral p–i–n diode. The resulting channel waveguide shows single mode operation and propagation losses of about 10 dB cm−1. The modulator optical behaviour is based on the vanishing of the lateral confinement in the rib region. Results show that an optical modulation depth close to 100% can be reached with a power expense of about 650 mW and an operation −3 dB bandwidth of about 25 MHz.

5 citations

Journal ArticleDOI
TL;DR: In this paper, the principle of the digital holography (DH) technique and the potentialities of the method are considered and experimental results obtained using the DH microscopy technique for characterizing microelectromechanical systems (MEMS) are presented and discussed.
Abstract: The principle of the digital holography (DH) technique and the potentialities of the method are considered. Experimental results obtained using the DH microscopy technique for characterizing microelectromechanical systems (MEMS) are presented and discussed.

5 citations

Proceedings ArticleDOI
TL;DR: In this article, a new refractive index sensor device based on the bound states in the continuum (BIC) resonance shift excited in a photonic crystal membrane was presented, and the shift of very high Q-factor resonances excited into the open cavity was monitored as a function of the refractive indices n of the test liquid.
Abstract: The realization of miniaturized devices able to accumulate a higher number of information in a smallest volume is a challenge of the technological development This trend increases the request of high sensitivity and selectivity sensors which can be integrated in microsystems In this landscape, optical sensors based on photonic crystal technology can be an appealing solution Here, a new refractive index sensor device, based on the bound states in the continuum (BIC) resonance shift excited in a photonic crystal membrane, is presented A microfluidic cell was used to control the injection of fluids with different refractive indices over the photonic crystal surface The shift of very high Q-factor resonances excited into the photonic crystal open cavity was monitored as a function of the refractive index n of the test liquid The excellent stability we found and the minimal, loss-free optical equipment requirement, provide a new route for achieving high performance in sensing applications

5 citations

Proceedings ArticleDOI
23 May 2013
TL;DR: The investigation of the identification and measurement of region of interest (ROI) in quantitative phase-contrast maps (QPMs) of biological cells by digital holographic microscopy (DHM) by using the anisotropic diffusion filter based on the Gaussian diffusivity function and the simple thresholding filter.
Abstract: We report the investigation of the identification and measurement of region of interest (ROI) in quantitative phase-contrast maps (QPMs) of biological cells by digital holographic microscopy (DHM), with the aim to analyze the 3D positions and 3D morphology together. We consider as test case for our tool the in vitro bull sperm head morphometry analysis. Extraction and measurement of various morphological parameters are performed by using two methods: the anisotropic diffusion filter, that is based on the Gaussian diffusivity function which allows more accuracy of the edge position, and the simple thresholding filter. In particular we consider the calculation of area, ellipticity, perimeter, major axis, minor axis and shape factor as a morphological parameter, instead, for the estimation of 3D position, we compute the centroid, the weighted centroid and the maximum phase values. A statistical analysis on a data set composed by N = 14 holograms relative to bovine spermatozoa and its reference holograms is reported.

4 citations

Journal ArticleDOI
TL;DR: In this article , a review of coronary artery disease in South Asian patients is presented, where the authors examine the leading cardiovascular risk factors determining increasing incidence in the South Asian population, such as insulin resistance, hypertension, dyslipidaemia and abdominal obesity caused by a diet rich in refined carbohydrates and saturated fats.

4 citations


Cited by
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Journal ArticleDOI

[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

Proceedings Article
01 Jan 1999
TL;DR: In this paper, the authors describe photonic crystals as the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures, and the interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.
Abstract: The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.

2,722 citations

Journal ArticleDOI
19 May 2005-Nature
TL;DR: Electro-optic modulators are one of the most critical components in optoelectronic integration, and decreasing their size may enable novel chip architectures, and here a high-speed electro-optical modulator in compact silicon structures is experimentally demonstrated.
Abstract: Metal interconnections are expected to become the limiting factor for the performance of electronic systems as transistors continue to shrink in size. Replacing them by optical interconnections, at different levels ranging from rack-to-rack down to chip-to-chip and intra-chip interconnections, could provide the low power dissipation, low latencies and high bandwidths that are needed. The implementation of optical interconnections relies on the development of micro-optical devices that are integrated with the microelectronics on chips. Recent demonstrations of silicon low-loss waveguides, light emitters, amplifiers and lasers approach this goal, but a small silicon electro-optic modulator with a size small enough for chip-scale integration has not yet been demonstrated. Here we experimentally demonstrate a high-speed electro-optical modulator in compact silicon structures. The modulator is based on a resonant light-confining structure that enhances the sensitivity of light to small changes in refractive index of the silicon and also enables high-speed operation. The modulator is 12 micrometres in diameter, three orders of magnitude smaller than previously demonstrated. Electro-optic modulators are one of the most critical components in optoelectronic integration, and decreasing their size may enable novel chip architectures.

2,336 citations

Journal ArticleDOI
TL;DR: The techniques that have, and will, be used to implement silicon optical modulators, as well as the outlook for these devices, and the candidate solutions of the future are discussed.
Abstract: Optical technology is poised to revolutionize short-reach interconnects. The leading candidate technology is silicon photonics, and the workhorse of such an interconnect is the optical modulator. Modulators have been improved dramatically in recent years, with a notable increase in bandwidth from the megahertz to the multigigahertz regime in just over half a decade. However, the demands of optical interconnects are significant, and many questions remain unanswered as to whether silicon can meet the required performance metrics. Minimizing metrics such as the device footprint and energy requirement per bit, while also maximizing bandwidth and modulation depth, is non-trivial. All of this must be achieved within an acceptable thermal tolerance and optical spectral width using CMOS-compatible fabrication processes. This Review discusses the techniques that have been (and will continue to be) used to implement silicon optical modulators, as well as providing an outlook for these devices and the candidate solutions of the future.

2,110 citations

Journal ArticleDOI
12 Feb 2004-Nature
TL;DR: An approach based on a metal–oxide–semiconductor (MOS) capacitor structure embedded in a silicon waveguide that can produce high-speed optical phase modulation is described and an all-silicon optical modulator with a modulation bandwidth exceeding 1 GHz is demonstrated.
Abstract: Silicon has long been the optimal material for electronics, but it is only relatively recently that it has been considered as a material option for photonics1. One of the key limitations for using silicon as a photonic material has been the relatively low speed of silicon optical modulators compared to those fabricated from III–V semiconductor compounds2,3,4,5,6 and/or electro-optic materials such as lithium niobate7,8,9. To date, the fastest silicon-waveguide-based optical modulator that has been demonstrated experimentally has a modulation frequency of only ∼20 MHz (refs 10, 11), although it has been predicted theoretically that a ∼1-GHz modulation frequency might be achievable in some device structures12,13. Here we describe an approach based on a metal–oxide–semiconductor (MOS) capacitor structure embedded in a silicon waveguide that can produce high-speed optical phase modulation: we demonstrate an all-silicon optical modulator with a modulation bandwidth exceeding 1 GHz. As this technology is compatible with conventional complementary MOS (CMOS) processing, monolithic integration of the silicon modulator with advanced electronics on a single silicon substrate becomes possible.

1,612 citations