Cyril Lupi
University of Nantes
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Publication
Featured researches published by Cyril Lupi.
Applied Physics Letters | 2003
Xavier Chapeleau; Dominique Leduc; Cyril Lupi; Roger Le Ny; Marc Douay; P. Niay; Christian Boisrobert
We apply a combination of optical low coherence reflectometry and a layer-peeling method to the synthesis of a fiber grating. The index modulation amplitude we obtain is compared with a Krug measurement result and the dc refractive index is derived from the phase measurement.
Journal of Optics | 2006
Xavier Chapeleau; Pascal Casari; Dominique Leduc; Y. Scudeller; Cyril Lupi; R. Le Ny; Christian Boisrobert
In this paper, a powerful method for measuring non-uniform strain is reviewed and extended to the measurement of temperature gradients inside an epoxy part. The sensor is an embedded fibre Bragg grating and the method is based on the measurements of the grating phase obtained by combining optical low coherence interferometry and an inverse scattering algorithm. This method has a great potential and for the first time experimental results obtained for both strain distribution and temperature gradient are presented. By applying a tensile test, strain distribution measurements are first compared with finite element simulations to validate previous published results. Second, original temperature gradient measurements in a solid body are shown. The results are in good accordance with reference measurements achieved with thermocouples incorporated into the body.
Applied Optics | 2006
Xavier Chapeleau; Dominique Leduc; Cyril Lupi; Francisco López-Gejo; Marc Douay; Roger Le Ny; Christian Boisrobert
The technique presented here allows us to obtain an accurate determination of the refractive index modulation amplitude, the mean effective index, and the chirp of fiber-Bragg gratings. A layer-peeling algorithm is used to extract this information from low-coherence interferometry measurements. Finally, we present a systematic study over 10 uniform and chirped gratings to proof the reliability and accuracy of this technique.
Journal of The European Ceramic Society | 2005
Julien Cardin; Dominique Leduc; Thomas Schneider; Cyril Lupi; Dominique Averty; Hartmut Gundel
In order to develop an electro-optic waveguide, Pb(Zr, Ti)O3 ceramic ferroelectric thin films were elaborated by a modified sol-gel process on glass substrate. In the aim to study the optical properties of the PZT films, an accurate refractive index and thickness measurement apparatus was set up, which is called M-lines device. An evaluation of experimental uncertainty and calculation of the precision of the refractive index and thickness were developed on PZT layers. Two different processes of PZT elaboration were made and studied with this apparatus. The reproducibility of one fabrication process was tested and results are presented in this paper.
Optical Materials | 2007
Thomas Schneider; Dominique Leduc; Julien Cardin; Cyril Lupi; N. Barreau; Hartmut Gundel
The optical properties of lead zirconate titanate (PZT) thin films deposited on ZnO were studied by m-lines spectroscopy. In order to retrieve the refractive index and the thickness of both layers from the m-lines spectra, we develop a numerical algorithm for the case of a two-layer system and show its robustness in the presence of noise. The sensitivity of the algorithm of the two-layer model allows us to relate the observed changes in the PZT refractive index to the PZT structural change due to the ZnO interface of the PZT/ZnO optical waveguide.
Smart Materials and Structures | 2013
Dominique Leduc; Yann Lecieux; Pierre-Antoine Morvan; Cyril Lupi
The aim of this paper is to investigate the ability to measure simultaneously the axial and radial strain with a single optical fiber sensor. The discussion begins with the analytical study of a cylinder subjected to pure tensile strain and thermal load. We emphasize the necessity of measuring the radial strain in order to determine the axial strain of an embedded sensor with accuracy. Then, we describe a few sensors able to measure axial and radial strains and study their efficiency. The conclusion is that the best structure is made of the juxtaposition of a short and a long period grating.
Journal of Optics | 2003
Dominique Leduc; Xavier Chapeleau; Cyril Lupi; Roger Le Ny; Christian Boisrobert
In this paper, we present more results obtained on fibre Bragg gratings submitted to Round Robin tests and compare them with those obtained at NIST. We confirm that the reflectance and the relative group delay can be accurately measured with optical low-coherence interferometry. Then, complete characterization of the reflectance and group delay of a free-space optics multiplexer/demultiplexer is performed. We show the similarity of the response of the different channels.
Journal of Applied Physics | 2008
Thomas Schneider; Dominique Leduc; Cyril Lupi; Julien Cardin; Hartmut Gundel; Christian Boisrobert
We consider three layer optical waveguides and present a method to measure simultaneously the refractive index and the thickness of each layer with m-lines spectroscopy. We establish the three layer waveguide modal dispersion equations and describe a numerical method to solve these equations. The accuracy of the method is evaluated by numerical simulations with noisy data and experimentally demonstrated using a PZT thin film placed between two ZnO layers.
Optical fiber and fiber component mechanical reliability and testing. Conference | 2001
Lotfi Berguiga; Cyril Lupi; Nicolas Hyon; L. Salomon; Guy Normand; Roger Le Ny; Eric Tanguy; Dominique Leduc; Monique Auvray; Jean Claude Bizeul; Alain Gouronnec; Frédérique de Fornel; Christian Boisrobert; Michel Poulain; Marcel Poulain
The reliability of the network optical fibers is a critical issue for telecommunications. New investigations methods have been developed within a cooperative program supported by France Telecom. They include low coherence interferometry and optical near field microscopy in association with classical analysis tools such as Scanning Electron Microscopy and Shear Force Microscopy. One aim of the study is the localization and the characterization of the defects from which failure originates. The aging effect has been investigated in silica fibers immersed in desionized water at 65 °C and 85 °C for different times : from 3 to 12 months
Fiber and Integrated Optics | 2009
Virginie Gaillard; X.A. Aduriz; N. Daher; Xavier Chapeleau; Dominique Leduc; Cyril Lupi; Nicholas Traynor; Pascal Casari; Christian Boisrobert
Abstract In this article, we describe local and spectral characterization of fibers and integrated optical components using low coherence interferometry. Chromatic dispersion and group birefringence measurements of erbium-doped fibers or photonic crystal fibers are presented, as well as local characterization of fiber Bragg gratings which allows the determination of strain and profile temperature gradient inside a material.