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Orsay, France

Gucsik A.,Kyoto University | Gucsik A.,Max Planck Institute for Chemistry | Nishido H.,Okayama University of Science | Ninagawa K.,Okayama University of Science | And 6 more authors.
Microscopy and Microanalysis | Year: 2012

Color centers in selected micro-and nanodiamond samples were investigated by cathodoluminescence (CL) microscopy and spectroscopy at 298 K [room temperature (RT)] and 77 K [liquid-nitrogen temperature (LNT)] to assess the value of the technique for astrophysics. Nanodiamonds from meteorites were compared with synthetic diamonds made with different processes involving distinct synthesis mechanisms (chemical vapor deposition, static high pressure high temperature, detonation). A CL emission peak centered at around 540 nm at 77 K was observed in almost all of the selected diamond samples and is assigned to the dislocation defect with nitrogen atoms. Additional peaks were identified at 387 and 452 nm, which are related to the vacancy defect. In general, peak intensity at LNT at the samples was increased in comparison to RT. The results indicate a clear temperature-dependence of the spectroscopic properties of diamond. This suggests the method is a useful tool in laboratory astrophysics. © 2012 Microscopy Society of America. Source


Baili G.,Thales Alenia | Morvan L.,Thales Alenia | Pillet G.,Thales Alenia | Bouchoule S.,CNRS Optic of Semiconductor nanoStructures Group | And 9 more authors.
Journal of Lightwave Technology | Year: 2014

We describe a compact, ultralow noise, and high-power semiconductor laser implemented in a high performances wideband externally modulated optical link. The laser is based on a vertical external cavity surface emitting laser (VECSEL) designed for high-power and low-noise operation. Thanks to a specific design of the gain chip, the half-VCSEL, based on a metamorphic Bragg mirror and a report on a copper substrate, an optical power of 110 mW is obtained at 1.55 μm in the single frequency regime. For low-noise operation, the laser cavity is designed for free-relaxation-oscillations operation, i.e., in the so-called class-A regime. The Class-A VECSEL exhibits a relative intensity noise below -170 dB/Hz over a wide frequency bandwidth, from 300 MHz to 40 GHz, except at the laser free spectral range (20.4 GHz). In the low-frequency range, the laser noise, mainly due to transfer of pump noise to laser noise, goes from -110 dB/Hz at 1 kHz down to -158 dB/Hz at 10 MHz. Two externally modulated optical links are implemented and compared in terms of the RF gain and the noise figure. The first optical link is based on the ultralow noise class-A VECSEL and the second one is based on a low noise class-B DFB laser. Thanks to the outstanding noise properties of the designed VECSEL, the VECSEL-based optical link outperforms the DFB-based one, in particular for frequencies larger than 20 GHz. © 2012 IEEE. Source


Mezei J.Z.,CNRS Laboratory of Waves and Complex Media | Mezei J.Z.,University Paris - Sud | Mezei J.Z.,Hungarian Academy of Sciences | Schneider I.F.,CNRS Laboratory of Waves and Complex Media | And 4 more authors.
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

Multichannel quantum defect theory is used to calculate photoionization cross sections for vibrationally excited diatomic hydrogen. The calculations are based on the state-of-the-art clamped-nuclei potential energy curves and electronic dipole transition moments of Wolniewicz. The calculations indicate that, in contrast to what had been assumed previously, autoionization resonances dominate the cross section. © 2012 American Physical Society. Source


Nowodzinski A.,CEA Grenoble | Chipaux M.,Thales Alenia | Chipaux M.,Laboratoire Aime Cotton | Chipaux M.,University of Groningen | And 5 more authors.
Microelectronics Reliability | Year: 2015

We present a novel technique based on an ensemble of Nitrogen-Vacancy (NV) centers of diamond to perform Magnetic Current Imaging (MCI) on an Integrated Circuit (IC). NV centers of diamond permit to measure the three components of the magnetic fields generated by mA range current in an IC structure over a field of 50 × 200 μm with sub-micrometric resolution. Vector measurements allow the use of a more robust algorithm than those used for MCI using GMR or SQUID sensors and it is opening new current reconstruction prospects. Calculated MCI from these measurements shows a very good agreement with theoretical current path. Acquisition time is around 10 s, which is much faster than scanning measurements using Superconducting Quantum Interference Device (SQUID) or Giant Magneto Resistance (GMR). The experimental set-up relies on a standard optical microscope, and the measurements can be performed at room temperature and atmospheric pressure. These early experiences, not optimized for IC, show that NV centers in diamond could become a real alternative for MCI in IC. © 2015 Elsevier Ltd. Source


Nowodzinski A.,CEA Grenoble | Chipaux M.,Thales Alenia | Toraille L.,Thales Alenia | Toraille L.,Ecole Normale Superieure de Lyon | And 3 more authors.
Microelectronics Reliability | Year: 2015

We present a novel technique based on an ensemble of Nitrogen-Vacancy (NV) centers of diamond to perform Magnetic Current Imaging (MCI) on an Integrated Circuit (IC). NV centers of diamond permit to measure the three components of the magnetic fields generated by mA range current in an IC structure over a field of 50. ×. 200. μm with sub-micrometric resolution. Vector measurements allow the use of a more robust algorithm than those used for MCI using GMR or SQUID sensors and it is opening new current reconstruction prospects. Calculated MCI from these measurements shows a very good agreement with theoretical current path. Acquisition time is around 10. s, which is much faster than scanning measurements using Superconducting Quantum Interference Device (SQUID) or Giant Magneto Resistance (GMR). The experimental set-up relies on a standard optical microscope, and the measurements can be performed at room temperature and atmospheric pressure. These early experiences, not optimized for IC, show that NV centers in diamond could become a real alternative for MCI in IC. © 2015 Elsevier Ltd. Source

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