Institute of Electronic Structure and Laser FORTH

Irákleion, Greece

Institute of Electronic Structure and Laser FORTH

Irákleion, Greece
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Panayiotidou L.,University of Cyprus | Drouza C.,Biotechnology and Food Science | Arabatzis N.,University of Cyprus | Lianos P.,Technological Educational Institute of Patra | And 4 more authors.
Polyhedron | Year: 2013

Twelve Pr3+, Sm3+, Eu3+, Gd3+, Tb3+ and Dy3+ complexes of N-(pyridin-2-ylmethylene) picolinohydrazonate (phzp-) were synthesized by the Ln3+ assisted hydrolysis of 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine. Crystallographic characterization of Pr3+, Sm3+ and Eu3+ hydrazonate complexes with nitrate or trifluoroacetyleacetonate co-ligands shows them to have binuclear structures with a planar Ln2O2 core and the ligand to be in its mono-anionic form. Exception is the Pr 3+ complex with nitrate co-ligand, which is a mononuclear species containing the neutral hydrazone. Paramagnetic 1D 1H and 2D gCOSY and gNOESY-gEXSY 1H NMR spectroscopies revealed the presence of different isomers exhibiting a sterically controlled fluxional behavior. In addition, phzp- significantly enhances the luminescence of Eu 3+ and Tb3+. Magnetic measurements show antiferromagnetic coupling between the Ln3+ ions in the dinuclear complexes. The structural characterization of the complexes in both solid state and solution show the versatility of phzp- ligand to adopt various ligating motifs. © 2013 Elsevier Ltd. All rights reserved.


Lalousis P.,Institute of Electronic Structure and Laser FORTH | Hora H.,University of New South Wales | Eliezer S.,Polytechnic University of Mozambique | Martinez-Val J.-M.,Polytechnic University of Mozambique | And 3 more authors.
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2013

Ignition of nuclear fusion flames in solid state density fuel following Chu's model of 1972 is evaluated using now available plasma blocks from ultrahigh acceleration with laser pulses of picosecond (ps) duration and power up to and beyond petawatt (PW). A new numerical approach is reported where genuine two-fluid hydrodynamics is used in order to study the shock mechanism of the generated fusion flame, its propagation velocities above 1000 km/s, and fusion efficiencies for deuterium-tritium needing an energy flux of 10 8 J/cm2. The results of the built-up of the shock process are reported showing a basic difference between the ps and nanosecond (ns) properties. © 2013 Elsevier B.V.


Foldes I.B.,EURATOM | Lalousis P.,Institute of Electronic Structure and Laser FORTH | Moustaizis S.,Technical University of Crete | Hora H.,University of New South Wales
AIP Conference Proceedings | Year: 2012

Interaction of picosecond laser pulses above terawatt power with high density plasmas shows a nearly 100% conversion of the laser energy into directed acceleration of the electron cloud by nonlinear (ponderomotive) forces giving the ion cloud accelerations several orders of magnitude higher than comparable nanosecond interaction based on thermal pressure processes. © 2012 American Institute of Physics.


Hora H.,University of New South Wales | Miley G.H.,Urbana University | Yang X.,Urbana University | Lalousis P.,Institute of Electronic Structure and Laser FORTH
Astrophysics and Space Science | Year: 2011

An extreme anomaly of laser-plasma interaction with petawatt-picosecond (PW-ps) pulses of very high contrast ratio for suppression of relativistic self-focusing permitted a come-back of the Bobin-Chu side-on ignition of uncompressed deuterium-tritium (DT) fusion fuel. The plasma blocks for the side-on ignition have to be produced by the well confirmed nonlinear force acceleration which is about 100,000 times higher than thermo-kinetic fluid-dynamic acceleration for comparison with astrophysical cases. It is essential that the dielectric plasma properties within the nonlinear force are used. Using the measured ion beam densities above 10 11 A s/cm 2 the ignition mechanism needed numerical and theoretical studies of extremely strong shock phenomena. When extending these results to the side-on ignition of uncompressed hydrogen-boron11 (HB11), surprisingly, the ignition by this shock mechanism was only about 10 times more difficult than for DT in contrast to ignition by spherical laser driven compression using thermo-kinetic conditions in which case HB11 ignition is 100,000 times more difficult than DT. © 2011 Springer Science+Business Media B.V.


Hora H.,University of New South Wales | Lalousis P.,Institute of Electronic Structure and Laser FORTH | Moustaizis S.,Technical University of Crete
Laser and Particle Beams | Year: 2014

One of the numerous applications of the ICAN laser using the advantage of fiber optics with chirped pulse amplification (CPA), is the scheme of side-on initiation of a nuclear fusion flame in solid density fuel with laser pulses of shorter than picosecond (ps) duration and power in the petawatt (PW) and higher range. The ICAN Fiber optics has special advantages with the potential that >900 PW spherical laser pulses may ignite the proton reaction with 11B (HB11) without the problem of dangerous radioactive radiation. Though secondary reactions can be estimated very roughly, the feasibility of a power station with the necessary energy gains can be concluded. © Cambridge University Press, 2013.


Tarkhanyan R.H.,Institute of Electronic Structure and Laser FORTH | Tarkhanyan R.H.,Armenian Institute of Radiophysics and Electronics | Niarchos D.G.,Greek National Center For Scientific Research
Physica Status Solidi (B) Basic Research | Year: 2011

A new class of nonradiative surface electromagnetic waves guided by the interface between two enantiomorph uniaxially bianisotropic media is predicted. The waves are caused by bianisotropy and are absent in the case of enantiomorph bi-isotropic materials. The basic properties of the waves, in particular, dispersion relation and localization conditions differ dramatically from those for conventional surface waves propagating along the interface between chiral and achiral media, as well as between two different achiral media. These waves can be considered as a generalization of Dyakonov-type surface waves in the case of enantiomeric bianisotropic media. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Tarkhanyan R.H.,Institute of Electronic Structure and Laser FORTH | Niarchos D.G.,Greek National Center For Scientific Research
Physica B: Condensed Matter | Year: 2010

The focus of this report is the investigation of the influence of an external magnetic field on the peculiarities of coupled magnon-plasmon polaritons in two different types of negative index gyromagnetic media: conducting antiferromagnets and nonconducting antiferromagnet/ nonmagneticdielectric periodic structures. The necessary conditions are found for realization of the negative refraction in such materials. It is shown that the behavior of the waves in various ranges of the magnetic field is quite different, and both the number and limits of the frequency ranges, where the negative refraction can be realized, are very sensitive to the strength of the applied field. © 2010 Elsevier B.V. All rights reserved.


Tarkhanyan R.H.,Institute of Electronic Structure and Laser FORTH | Niarchos D.G.,Greek National Center For Scientific Research | Kafesaki M.,Institute of Electronic Structure and Laser FORTH
Journal of Magnetism and Magnetic Materials | Year: 2010

The peculiarities of the negative refraction in periodic multilayered antiferromagnet-semiconductor nanostructures are investigated in the presence of an external magnetic field parallel to the plane of the layers. Effective material tensors are obtained using method of anisotropic homogeneous medium. Dispersion and energetic relations for the mixed magnon-plasmon polaritons are investigated in the case of the Voigt geometry. Frequency regions of anomalous dispersion are found and studied in various regimes of the applied magnetic field. The necessary conditions are found under which the structure behaves as a left-handed negative-index metamaterial. Analytical expressions for the frequency-dependent phase and group refractive indices are obtained. © 2009 Elsevier B.V. All rights reserved.


Somaschi N.,Institute of Electronic Structure and Laser FORTH | Somaschi N.,University of Southampton | Tsintzos S.,Institute of Electronic Structure and Laser FORTH | Coles D.,University of Sheffield | And 6 more authors.
2013 Conference on Lasers and Electro-Optics, CLEO 2013 | Year: 2013

Exciton-polariton states that arise from strong coupling of hybridized Frenkel and Wannier-Mott excitons with cavity photons are theoretically predicted [1,2] to exhibit large radius, small saturation density and large oscillator strength at the same time. These new features should strongly favorite observation of non-linear phenomena and overcome intrinsic limitation of both type of semiconductors. Here we fabricate and study a multilayered structure that combines GaAs QWs and molecular J-aggregate cyanine dye in a high Q planar microcavity. Strong coupling regime is achieved due to interaction of both exciton species with the cavity photons. The implementation of a light emitting diode design with electrical pumping of excitons in the inorganic QWs would be especially significant for both optoelectronic device applications (electrically pumped organic polariton laser) and fundamental studies of exciton dynamics in a microcavity system. © 2013 The Optical Society.

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