72 research outputs found
Near-Resonant Nonlinear Optical Properties of Pseudoisocyanine J-Aggregates in Langmuir-Blodgett Layers
Nonlinear Bessel beams
The effect of the Kerr nonlinearity on linear non-diffractive Bessel beams is
investigated analytically and numerically using the nonlinear Schr\"odinger
equation. The nonlinearity is shown to primarily affect the central parts of
the Bessel beam, giving rise to radial compression or decompression depending
on whether the nonlinearity is focusing or defocusing, respectively. The
dynamical properties of Gaussian-truncated Bessel beams are also analysed in
the presence of a Kerr nonlinearity. It is found that although a condition for
width balance in the root-mean-square sense exists, the beam profile becomes
strongly deformed during propagation and may exhibit the phenomena of global
and partial collapse.Comment: 15 pages, 7 figure
Characterization and modelling of the hollow beam produced by a real conical lens
The properties of the hollow beam produced by a conical lens are studied in
detail. In particular, the impact of a rounded vertex is examined. It is shown
that it could lead to drastic changes in the transverse distribution of the
hollow beam, determined by the ratio between the transverse size of the
incident beam and the size of the blunt area. An adequate choice for this ratio
allows us to either minimize the losses or optimize the distribution symmetry.Comment: 13 pages, 10 figures, submitted to Optics Communication
One- and two-photon picosecond processes of electron transfer among the porphyrin molecules in bacterial reaction centers
Spatial Filters on Demand Based on Aperiodic Photonic Crystals
Photonic Crystal spatial filters, apart from stand-alone spatial filtering function, can also suppress multi-transverse-mode operation in laser resonators. Here it is shown that such photonic crystals can be designed by solving the inverse problem: for a given spatial filtering profile. Optimized Photonic Crystal filters were fabricated in photosensitive glass. Experiments have shown that such filters provide a more pronounced filtering effect for total and partial transmissivity conditions.Peer ReviewedPostprint (published version
Localization and coherent dynamics of excitons in the two-dimensional optical spectrum of molecular J-aggregates
SYLOS lasers - the frontier of few-cycle, multi-TW, kHz lasers for ultrafast applications at extreme light infrastructure attosecond light pulse source
Organic dye doped microstructures for optically active functional devices fabricated via two-photon polymerization technique
Influence of hybrid organicâinorganic solâgel matrices on the photophysics of amino-functionalized UV-sensitizers
Excited-State Dynamics of Hybrid Multichromophoric Systems: Toward an Excitation Wavelength Control of the Charge Separation Pathways
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