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E Louvergneaux

Publications and source records attributed to E Louvergneaux.

4 recordsLinked to original sources
PubMed2004

Average patterns and coherent phenomena in wide aperture lasers.

Using a realistic model of wide aperture, weakly astigmatic lasers we develop a framework to analyze experimental average intensity patterns. We use the model to explain the appearance of patterns in terms of the modes of the cavity and to show that the breaking of the symmetry of the average intensity patterns is caused by overlaps in the frequency spectra of nonvanishing of modes with different parity. This result can be used even in systems with very fast dynamics to detect experimentally overlaps of frequency spectra of modes.

Journal Article↗
PubMed2001

Pattern-dislocation-type dynamical instability in 1D optical feedback Kerr media with Gaussian transverse pumping.

We study experimentally and numerically the secondary instability corresponding to the destabilization of stationary transverse roll patterns appearing in a 1D liquid crystal layer subjected to optical feedback. This dynamical instability appears as roll dislocations in the spatiotemporal diagrams. We show that it originates from the Gaussian spatial transverse dependence of a control parameter and that its corresponding mechanism is the selection of a local unstable wave number. This instability is the optical counterpart of the ramp-induced Eckhaus instability observed in hydrodynamics.

Journal Article↗