Search results for "Optical physics"
showing 5 items of 35 documents
Reply to 'The super-quadratic growth of high-harmonic signal as a function of pressure'
2010
Ab initio molecular dynamics studies of Au38(SR)24 isomers under heating
2019
Despite the great success in achieving monodispersity for a great number of monolayer-protected clusters, to date little is known about the dynamics of these ultra-small metal systems, their decomposition mechanisms, and the energy that separates their structural isomers. In this work, we use density functional theory (DFT) to calculate and compare the ground state energy and the Born-Oppenheimer molecular dynamics of two well-known Au 38 (SCH 2 CH 2 Ph) 24 nanocluster isomers. The aim is to shed light on the energy difference between the two clusters isomers and analyze their decomposition mechanisms triggered by high temperatures. The results demonstrate that the energy that separates the…
Ytterbium-doped fiber laser as pulsed source of narrowband amplified spontaneous emission
2019
AbstractWe report random noise pulsed regime of an ytterbium-doped fiber laser arranged in common Fabry-Perot configuration. We show that the laser output obeys the photon statistics inherent to narrowband amplified spontaneous emission and that the noise pulsing is properly addressed in terms of probability density and autocorrelation functions. Our novel approach reveals, in particular, that the regime’s coherence time dramatically shortens, from few ns to tens ps, with increasing laser power.
Observation of light-by-light polarization control and stabilization in optical fibre for telecommunication applications
2010
International audience; In many photonics applications, especially in optical fibre based systems, the state of polarization of light remains so far an elusive uncontrolled variable, which can dramatically affect the performances of that systems and which one would like to control as finely as possible. Here, we experimentally demonstrate light-by-light polarization control via a nonlinear effect occurring in single mode optical fibre. We observe a polarization attraction and stabilization of a 10 Gbit/s optical telecommunication signal around 1550 nm. We also validate the potentiality of the device to annihilate very fast nanosecond polarization bursts. This result confirms yet another fas…
Towards a Rapid Screening of Liver Grafts at the Operating Room Using Mid-Infrared Spectroscopy
2020
The estimation of steatosis in a liver graft is mandatory prior to liver transplantation, as the risk of graft failure increases with the level of infiltrated fat. However, the assessment of liver steatosis before transplantation is typically based on a qualitative or semiquantitative characterization by visual inspection and palpation and histological analysis. Thus, there is an unmet need for transplantation surgeons to have access to a diagnostic tool enabling an in situ fast classification of grafts prior to extraction. In this study, we have assessed an attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopic method compatible with the requirements of an operatio…