N. Kroó - Academia.edu (original) (raw)
Papers by N. Kroó
Acta Physica Academiae Scientiarum Hungaricae, 1981
ABSTRACT
Surface Science, 1996
An ATR reflectometer was constructed using a twin goniometer system and lock-in detection techniq... more An ATR reflectometer was constructed using a twin goniometer system and lock-in detection technique. The angular resolution was ±0.015°, determined by the beam divergence of the HeNe and YAG laser light sources, while the error in reflectivity was less than ±2%. The angular distribution of the ATR reflection and backward resonance light emission was measured in evaporated silver and gold
physica status solidi (b), 1980
ABSTRACT
Physica Status Solidi (a), 1981
ABSTRACT Crystalline and liquid crystalline phases as well as the fast cooled state of the smecti... more ABSTRACT Crystalline and liquid crystalline phases as well as the fast cooled state of the smectic liquid crystal compound p-n-decyloxybenzoic acid -p-n-hexyloxyphenyl ester (DOBHOP) are studied. On quenching from the liquid crystal phase a glassy state freezes out, exhibiting a structure similar to a smectic phase as measured by neutron diffraction. Raman spectra of the ordered and disordered states show that the change of the density of states of intermolecular vibration in a crystal-liquid crystal phase transition is mainly determined by the change of the structure, though the translational motion of molecules and anharmonicity also play a role.[Russian Text Ignored].
Journal of Modern Optics, 2011
Intensity-intensity correlations are studied for light signals stemming from the spontaneous deca... more Intensity-intensity correlations are studied for light signals stemming from the spontaneous decay of surface plasmon oscillations, generated in the Kretschmann geometry. Non-classical photon statistics and the transition from antibunching to bunching of the electron counts have been found experimentally and analysed on a new theoretical basis.
EPL (Europhysics Letters), 2014
The basis of low-temperature superconductivity has been set to be the pair formation of electrons... more The basis of low-temperature superconductivity has been set to be the pair formation of electrons, due to their effective attraction. The appearance of an effective attraction potential has also been predicted for electron-electron scattering in the presence of strong, inhomogeneous radiation field. In the present work the strong electromagnetic fields were created by femtosecond Ti:Sa lasers, used to excite surface plasmons in gold films at room temperature in the Kretschmann geometry. Experimental investigations were carried out using a surface plasmon near field scanning tunneling microscope, measuring it's response to the excitation at hot spots on the gold surface. Furthermore, the spectra of photoelectrons, liberated by multi-plasmon absorption, has also been measured by a timeof-flight spectrometer. In both cases new type of anomalies in the electron signal have been measured in the same intensity range, whose existence may be qualitatively understood, by using the intensity-dependent expression for the effective electronelectron scattering potential, derived earlier in a different context.
Optics Express, 2010
We present experimental evidence of the generation of few-cycle propagating surface plasmon polar... more We present experimental evidence of the generation of few-cycle propagating surface plasmon polariton wavepackets. These ultrashort plasmonic pulses comprised of only 2-3 field oscillations were characterized by an autocorrelation measurement based on electron photoemission. By exploiting plasmonic field enhancement, we achieved plasmon-induced tunnelling emission from the metal surface at low laser intensity, opening perspectives for strong-field experiments with low pulse energies. All-optical electron acceleration up to keV kinetic energy is also demonstrated in these surface-confined, few-cycle fields with only 1.35 × 10 12 W/cm 2 focused laser intensity. The experimental results are found to be in excellent agreement with the model.
Acta Physica Academiae Scientiarum Hungaricae, 1981
ABSTRACT
Surface Science, 1996
An ATR reflectometer was constructed using a twin goniometer system and lock-in detection techniq... more An ATR reflectometer was constructed using a twin goniometer system and lock-in detection technique. The angular resolution was ±0.015°, determined by the beam divergence of the HeNe and YAG laser light sources, while the error in reflectivity was less than ±2%. The angular distribution of the ATR reflection and backward resonance light emission was measured in evaporated silver and gold
physica status solidi (b), 1980
ABSTRACT
Physica Status Solidi (a), 1981
ABSTRACT Crystalline and liquid crystalline phases as well as the fast cooled state of the smecti... more ABSTRACT Crystalline and liquid crystalline phases as well as the fast cooled state of the smectic liquid crystal compound p-n-decyloxybenzoic acid -p-n-hexyloxyphenyl ester (DOBHOP) are studied. On quenching from the liquid crystal phase a glassy state freezes out, exhibiting a structure similar to a smectic phase as measured by neutron diffraction. Raman spectra of the ordered and disordered states show that the change of the density of states of intermolecular vibration in a crystal-liquid crystal phase transition is mainly determined by the change of the structure, though the translational motion of molecules and anharmonicity also play a role.[Russian Text Ignored].
Journal of Modern Optics, 2011
Intensity-intensity correlations are studied for light signals stemming from the spontaneous deca... more Intensity-intensity correlations are studied for light signals stemming from the spontaneous decay of surface plasmon oscillations, generated in the Kretschmann geometry. Non-classical photon statistics and the transition from antibunching to bunching of the electron counts have been found experimentally and analysed on a new theoretical basis.
EPL (Europhysics Letters), 2014
The basis of low-temperature superconductivity has been set to be the pair formation of electrons... more The basis of low-temperature superconductivity has been set to be the pair formation of electrons, due to their effective attraction. The appearance of an effective attraction potential has also been predicted for electron-electron scattering in the presence of strong, inhomogeneous radiation field. In the present work the strong electromagnetic fields were created by femtosecond Ti:Sa lasers, used to excite surface plasmons in gold films at room temperature in the Kretschmann geometry. Experimental investigations were carried out using a surface plasmon near field scanning tunneling microscope, measuring it's response to the excitation at hot spots on the gold surface. Furthermore, the spectra of photoelectrons, liberated by multi-plasmon absorption, has also been measured by a timeof-flight spectrometer. In both cases new type of anomalies in the electron signal have been measured in the same intensity range, whose existence may be qualitatively understood, by using the intensity-dependent expression for the effective electronelectron scattering potential, derived earlier in a different context.
Optics Express, 2010
We present experimental evidence of the generation of few-cycle propagating surface plasmon polar... more We present experimental evidence of the generation of few-cycle propagating surface plasmon polariton wavepackets. These ultrashort plasmonic pulses comprised of only 2-3 field oscillations were characterized by an autocorrelation measurement based on electron photoemission. By exploiting plasmonic field enhancement, we achieved plasmon-induced tunnelling emission from the metal surface at low laser intensity, opening perspectives for strong-field experiments with low pulse energies. All-optical electron acceleration up to keV kinetic energy is also demonstrated in these surface-confined, few-cycle fields with only 1.35 × 10 12 W/cm 2 focused laser intensity. The experimental results are found to be in excellent agreement with the model.