P. André - Academia.edu (original) (raw)
Papers by P. André
Journal Européen des Urgences, 2008
Optical Engineering, 2003
Abstract In this contribution we compare the thermal tuning capabilities of two type I gratings w... more Abstract In this contribution we compare the thermal tuning capabilities of two type I gratings written in an unloaded and a hydrogen-loaded germanium doped silica fibres, and a type IIa grating written in unloaded ,fibre. The hydrogen-loaded grating is annealed after writing, to remove any unreacted hydrogen. We further study grating response stability with temperature, an important property when these
2010 12th International Conference on Transparent Optical Networks, ICTON 2010, 2010
Here, we propose a new configuration to remotely detect the fiber fuse propagation. This configur... more Here, we propose a new configuration to remotely detect the fiber fuse propagation. This configuration uses a Fiber Bragg Gratings (FBG) as temperature sensor to monitor the displacement of the thermal wave associated with the fuse effect.
2010 12th International Conference on Transparent Optical Networks, ICTON 2010, 2010
In this paper, direct UV-laser writing was used to produce channel waveguides and diffraction gra... more In this paper, direct UV-laser writing was used to produce channel waveguides and diffraction gratings on thin films of siliceous-based organic-inorganic hybrid materials. The optical quality of the films surface was studied by light scattering measurements. The produced Y-power splitters, optical filters and Fabry-Perot cavities were experimentally characterized for propagation in the near infrared spectral region.
Photonic Network Communications, 2002
In this paper, we assess the design and performances of a strictly non-blocking all-optical cross... more In this paper, we assess the design and performances of a strictly non-blocking all-optical cross-connect demonstrator node for WDM wavelength path networks. The all-optical cross-connect (AOXC) prototype was experimentally tested in a small 262 WDM network with a STM-16 bit stream per channel. The single and cascaded performance of the AOXC was also simulated and its results were validated with the experimental ones.
The Journal of Physical Chemistry B, 2008
The aim of this publication is to present a general strategy to engineer more efficient photolumi... more The aim of this publication is to present a general strategy to engineer more efficient photoluminescent dendritic molecules based on polyhedral oligomeric silsesquioxane (POSS) cores. A series of chromophores were grafted on POSS cores to form dendritic molecules for which steric hindrance was used as a trigger to tune their photophysical properties. For fluorescence in the blue/near-UV spectral ranges, 4-vinylbiphenyl molecules were chosen as model chromophores to present a general approach based on stable chemistry and bulky groups grafted to the chromophores to enhance photoluminescence efficiency of the dendritic molecules. Photoluminescence quantum yields as well as steady-state and time-resolved solution spectroscopy along with molecular dynamics investigation and electronic structure calculations on a family of new materials are reported. We highlight an apparent contrast between free chromophore and dendritic molecules photophysical properties and show that chromophores' engineering and confinement around an inorganic core allows the design of more efficient photoluminescent dendritic molecules relevant to sensors and hybrid light-emitting diodes.
Microwave and Optical Technology Letters, 2012
This article analyzes experimentally the limitations observed in a 45 km Raman amplified 4 Â 40 G... more This article analyzes experimentally the limitations observed in a 45 km Raman amplified 4 Â 40 Gb/s transmission system operating under multiple pump and single high pump power configurations. A signal-to-noise ratio of 19.2 dB, an extinction ratio of 10.4 dB and a jitter of 1097 fs are achieved for moderate pump powers and higher order stimulated Brillouin scattering lines give rise to system degradation for pump power levels more than 0.5 W.
Journal of Applied Physics, 1997
The diffusion of defects during the thermal growth of SiO 2 film on Si͑100͒ in dry O 2 was invest... more The diffusion of defects during the thermal growth of SiO 2 film on Si͑100͒ in dry O 2 was investigated using sequential treatments in natural oxygen ( 16 O 2 ) and in heavy oxygen ( 18 O 2 ) in a Joule effect furnace. The 18 O depth profiles were measured with a depth resolution better than 1 nm, using the nuclear reaction narrow resonance 18 O(p,␣) 15 N ͑E R ϭ151 keV, ⌫ R ϭ100 eV͒. From these profiles, we confirmed that just below the surface an exchange between the oxygen atoms from the gas phase and those from the silica occurs, even for silica films thicker than 20 nm. This fact is not predicted by the Deal and Grove model. A diffusion of oxygen related defects takes place in the near surface region, with an apparent diffusion coefficient D*ϭ4.33ϫ10 Ϫ19 cm 2 /s for an oxidation temperature of Tϭ930°C and for an oxygen pressure of Pϭ100 mbar. © 1997 American Institute of Physics. ͓S0021-8979͑97͒02212-3͔
IET Optoelectronics, 2012
Electronics Letters, 2010
ABSTRACT Long-term optical network reliability is highly dependent on the fibre quality. However,... more ABSTRACT Long-term optical network reliability is highly dependent on the fibre quality. However, poor handling or installation can impose bendings in the optical fibres, leading to a significant increase in link losses, which results in fibre coating degradation owing to heating occurring in the presence of high power signals propagation. Presented, for the first time, is an accurate thermal model for optical fibres under tight bending and high power conditions.
Electronics Letters, 2005
ABSTRACT
... operation scenario but the resilient operation scenario is affected by a high gain ripple and... more ... operation scenario but the resilient operation scenario is affected by a high gain ripple and Kerr nonlinear effects due to the high power achieved are very penalizing. REFERENCES [1] NB Pavlovic, A. Baptista, B. Neto, A. Rocha. P. André, D. Forin, GT Beleffi, JA Lazaro, J. Prat ...
We investigate the effect of temperature on the optical fibers chromatic dispersion and chromatic... more We investigate the effect of temperature on the optical fibers chromatic dispersion and chromatic dispersion slope, once these parameters will affect dispersion compensation at high bit rates. We derive an expression for the chromatic dispersion slope variation with temperature as function of the zero dispersion wavelength and chromatic dispersion slope at the zero dispersion wavelength. We also verify that this last term has a high contribution for the total chromatic dispersion variation, and cannot be ignored. We show that the model of Ghosh et al for the Silica refractive index temperature dependence can be used to describe the variation of the dispersion slope within the temperature interval between-40 ºC and 60 º C. Through numerical simulation we verify that the effect of temperature cannot be ignored in the design of dispersion compensation devices for high debit systems (40 Gbit/s).
Journal Européen des Urgences, 2008
Optical Engineering, 2003
Abstract In this contribution we compare the thermal tuning capabilities of two type I gratings w... more Abstract In this contribution we compare the thermal tuning capabilities of two type I gratings written in an unloaded and a hydrogen-loaded germanium doped silica fibres, and a type IIa grating written in unloaded ,fibre. The hydrogen-loaded grating is annealed after writing, to remove any unreacted hydrogen. We further study grating response stability with temperature, an important property when these
2010 12th International Conference on Transparent Optical Networks, ICTON 2010, 2010
Here, we propose a new configuration to remotely detect the fiber fuse propagation. This configur... more Here, we propose a new configuration to remotely detect the fiber fuse propagation. This configuration uses a Fiber Bragg Gratings (FBG) as temperature sensor to monitor the displacement of the thermal wave associated with the fuse effect.
2010 12th International Conference on Transparent Optical Networks, ICTON 2010, 2010
In this paper, direct UV-laser writing was used to produce channel waveguides and diffraction gra... more In this paper, direct UV-laser writing was used to produce channel waveguides and diffraction gratings on thin films of siliceous-based organic-inorganic hybrid materials. The optical quality of the films surface was studied by light scattering measurements. The produced Y-power splitters, optical filters and Fabry-Perot cavities were experimentally characterized for propagation in the near infrared spectral region.
Photonic Network Communications, 2002
In this paper, we assess the design and performances of a strictly non-blocking all-optical cross... more In this paper, we assess the design and performances of a strictly non-blocking all-optical cross-connect demonstrator node for WDM wavelength path networks. The all-optical cross-connect (AOXC) prototype was experimentally tested in a small 262 WDM network with a STM-16 bit stream per channel. The single and cascaded performance of the AOXC was also simulated and its results were validated with the experimental ones.
The Journal of Physical Chemistry B, 2008
The aim of this publication is to present a general strategy to engineer more efficient photolumi... more The aim of this publication is to present a general strategy to engineer more efficient photoluminescent dendritic molecules based on polyhedral oligomeric silsesquioxane (POSS) cores. A series of chromophores were grafted on POSS cores to form dendritic molecules for which steric hindrance was used as a trigger to tune their photophysical properties. For fluorescence in the blue/near-UV spectral ranges, 4-vinylbiphenyl molecules were chosen as model chromophores to present a general approach based on stable chemistry and bulky groups grafted to the chromophores to enhance photoluminescence efficiency of the dendritic molecules. Photoluminescence quantum yields as well as steady-state and time-resolved solution spectroscopy along with molecular dynamics investigation and electronic structure calculations on a family of new materials are reported. We highlight an apparent contrast between free chromophore and dendritic molecules photophysical properties and show that chromophores' engineering and confinement around an inorganic core allows the design of more efficient photoluminescent dendritic molecules relevant to sensors and hybrid light-emitting diodes.
Microwave and Optical Technology Letters, 2012
This article analyzes experimentally the limitations observed in a 45 km Raman amplified 4 Â 40 G... more This article analyzes experimentally the limitations observed in a 45 km Raman amplified 4 Â 40 Gb/s transmission system operating under multiple pump and single high pump power configurations. A signal-to-noise ratio of 19.2 dB, an extinction ratio of 10.4 dB and a jitter of 1097 fs are achieved for moderate pump powers and higher order stimulated Brillouin scattering lines give rise to system degradation for pump power levels more than 0.5 W.
Journal of Applied Physics, 1997
The diffusion of defects during the thermal growth of SiO 2 film on Si͑100͒ in dry O 2 was invest... more The diffusion of defects during the thermal growth of SiO 2 film on Si͑100͒ in dry O 2 was investigated using sequential treatments in natural oxygen ( 16 O 2 ) and in heavy oxygen ( 18 O 2 ) in a Joule effect furnace. The 18 O depth profiles were measured with a depth resolution better than 1 nm, using the nuclear reaction narrow resonance 18 O(p,␣) 15 N ͑E R ϭ151 keV, ⌫ R ϭ100 eV͒. From these profiles, we confirmed that just below the surface an exchange between the oxygen atoms from the gas phase and those from the silica occurs, even for silica films thicker than 20 nm. This fact is not predicted by the Deal and Grove model. A diffusion of oxygen related defects takes place in the near surface region, with an apparent diffusion coefficient D*ϭ4.33ϫ10 Ϫ19 cm 2 /s for an oxidation temperature of Tϭ930°C and for an oxygen pressure of Pϭ100 mbar. © 1997 American Institute of Physics. ͓S0021-8979͑97͒02212-3͔
IET Optoelectronics, 2012
Electronics Letters, 2010
ABSTRACT Long-term optical network reliability is highly dependent on the fibre quality. However,... more ABSTRACT Long-term optical network reliability is highly dependent on the fibre quality. However, poor handling or installation can impose bendings in the optical fibres, leading to a significant increase in link losses, which results in fibre coating degradation owing to heating occurring in the presence of high power signals propagation. Presented, for the first time, is an accurate thermal model for optical fibres under tight bending and high power conditions.
Electronics Letters, 2005
ABSTRACT
... operation scenario but the resilient operation scenario is affected by a high gain ripple and... more ... operation scenario but the resilient operation scenario is affected by a high gain ripple and Kerr nonlinear effects due to the high power achieved are very penalizing. REFERENCES [1] NB Pavlovic, A. Baptista, B. Neto, A. Rocha. P. André, D. Forin, GT Beleffi, JA Lazaro, J. Prat ...
We investigate the effect of temperature on the optical fibers chromatic dispersion and chromatic... more We investigate the effect of temperature on the optical fibers chromatic dispersion and chromatic dispersion slope, once these parameters will affect dispersion compensation at high bit rates. We derive an expression for the chromatic dispersion slope variation with temperature as function of the zero dispersion wavelength and chromatic dispersion slope at the zero dispersion wavelength. We also verify that this last term has a high contribution for the total chromatic dispersion variation, and cannot be ignored. We show that the model of Ghosh et al for the Silica refractive index temperature dependence can be used to describe the variation of the dispersion slope within the temperature interval between-40 ºC and 60 º C. Through numerical simulation we verify that the effect of temperature cannot be ignored in the design of dispersion compensation devices for high debit systems (40 Gbit/s).