Merging multireference perturbation and density-functional theories by means of range separations: Potential curves for Be2, Mg2 and Ca2

A rigorous combination of multireference perturbation theory and density functional theory (DFT) is proposed. Based on a range separation of the regular two-electron Coulomb interaction, it combines a short-range density functional with second-order strongly contracted n-electron valence state perturbation theory (sc-NEVPT2). The huge advantage of the sc-NEVPT2 approach is that the density is unchanged through first order due to a generalized-Brillouin-type theorem so that the computationally cumbersome self-consistency contribution of short-range DFT to the second-order energy correction equals zero. The method yields very promising results for the van der Waals systems Be2, Mg2 and Ca2

Structuring a laser beam subject to optical Kerr effect for improving its focusing properties

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Optique binaire pour la mise en forme spatiale de faisceaux laser IR, visible et UV

Nous montrons les possibilités de mises en forme d'amplitude et de polarisation des faisceaux laser qu'offrent quelques Eléments Optiques Diffractifs binaires simples

Transverse pseudo-nonlinear effects measured in solid-state laser materials using a sensitive time-resolved technique

We present a detailed study of the Baryscan technique, a new efficient alternative to the widespread Z-scan technique which has been demonstrated [Opt. Lett. 36:8, 2011] to reach among the highest sensitivity levels. This method is based upon the measurement of optical nonlinearities by means of beam centroid displacements with a position sensitive detector and is able to deal with any kind of lensing effect. This technique is applied here to measure pump-induced electronic refractive index changes (population lens), which can be discriminated from parasitic thermal effects by using a time-resolved Baryscan experiment. This method is validated by evaluating the polarizability variation at the origin of the population lens observed in the reference Cr3+:GSGG laser material.Conseil Regional Basse-NormandieConseil Regional BasseNormandi