Laser Physics Department
Interaction of strong laser light with matter
List of publications (since 1994)
The most important subjects studied by our research group:
- Construction of a laser system producing petawatt (1015 W) intensities based on the "Chirped Pulse Amplification" principle.
- Experimental studies and theoretical interpretation of the new type photoelectron emission processes revealed by us using far infrared lasers.
- Realisation of extreme intensive electron sources and special light (e.g. X-ray) sources, which deliver extreme short (10-12 - 10-15 sec) duration strong electron and light pulses, with the help of the laser induced multiphoton photoeffect and multiharmonic generation on metal surfaces.
- Theoretical description of the new type laser acceleration (up to GeV energies) and the strong (Terawatt intensities) X-ray pulse generation, based on the laser induced multiphoton absorption process of electrons, observed by us earlier at collisions of electron pulses and laser pulses
Further information:
Gy. Farkas, E-Mail: 
Gas laser research
List of publications (since 1994)
The subject of the research is investigation of gas discharge and laser physics problems of low power continuously operating visible and ultraviolet gas lasers.
In the field of gas discharges the electrical and optical characteristics of normal and increased voltage hollow cathode discharges is investigated theoretically by Monte-Carlo simulation methods and by experimental measurements.
An electrolyte cathode atmospheric pressure discharge has been developed, in which the cathode sputtering of electrolyte solutions is investigated.
Gas laser excitation mechanism are investigated in noble gas mixture hollow cathode lasers, while in the field of ultraviolet metal vapour lasers the connection between laser operation parameters and cathode voltage is the subject of research.
Further information:
Károly Rózsa, E-mail: 
Optical studies of metal and fullerene films
List of publications (since 1994)
An experimental arrangement was set up for high precision measurement of attenuated total reflection (ATR) using the electromagnetic surface waves (plasmons) mediated reflectance in thin silver and gold films of 10-100 nm thickness. The error in reflectivity was less than 1 %. The measurements were performed at 633, 809 at 1064 laser wavelengths.
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700 Å thick gold layer on silicon base, AFM image of 1x1 μm. Place of a dust grain, which fell down after the deposition of the layer.
Click on the picture to get a bigger view. |
We developed a multichannel reflectometer using a white lamp as light source for measurement in the whole visible and near infrared spectrum (400-950 nm).
A software was developed for evaluation of ATR reflectivity measurements based on fitting the measured data (reflection dip) by the matrix form of Fresnel's reflection equations. With this method we can calculate the optical constants and thicknesses of thermally evaporated metal and dielectric adlayers (as e.g. the C60).
This measuring system was also used to determine the angular distribution of the rear-side light emission, while the sample stands in the ATR resonance position. From these intensity-angle plots one can calculate the roughness parameters (correlation length and rms height) using theoretical models. Supplementary measurements were made by atomic force and transmission electron microscopies and small angle X-ray diffraction.
Further information:
Norbert Kroó, E-mail: 
Relevant publications
F.F. Körmendi*, Gy. Farkas: Soft X-ray generation by multiphoton scattering of a laser beam from fast electrons. Phys. Rev. A53, R637 (1996)
S. Varró and F. Ehlotzky*: Higher harmonic generation at metal surfaces by femtosecond laser pulses. Phys. Rev. A54, 3245 (1996)
F.F. Körmendi*, Gy. Farkas: Laser accelerators and X-ray generators based on multiphoton processes. Laser Physics, 7, 583 (1997)
Z. Donkó: Avalanches and bursts in low pressure helium gas below the breakdown voltage. Phys. Rev. E51, 3934 (1995)
K. Rózsa, A. Gallagher and Z. Donkó: Excitation of Ar lines in the cathode region of a DC discharge. Phys. Rev. E52, 913 (1995)
Z. Donkó, K. Rózsa and R.C. Tobin: Monte Carlo analysis of the electrons' motion in a segmented hollow cathode discharge. J. Phys. D29, 105 (1996)
T. Adamowicz, Z. Donkó, L. Szalai, K. Rózsa, W. Kwasniewski: The spatial distribution of small signal gain in a segmented hollow cathode discharge laser. Appl. Phys. B65, 613 (1997)
B. Leigh, R.C. Tobin, K. Rózsa and Z. Donkó: Dependence of gain and output power on cathode to anode area ratio in a segmented hollow-cathode Cu-II 781 nm laser. J. Phys. D30, 2946 (1997)
T. Cserfalvi*, P. Mezei, P. Apai: Emission studies on a glow discharge in atmospheric pressure air using water as a cathode. J. Phys. D26, 2184 (1993)
T. Cserfalvi*, P. Mezei: Direct Solution Analysis by Glow Discharge: Electrolyte-Cathode Discharge Spectrometry. J. Anal. Spectr. 9, 345 (1994)
T. Cserfalvi*, P. Mezei: Operating mechanism of the electrolyte cathode atmospheric glow discharge. Fresen. J. Anal. Chem. 355, 813 (1996)
P. Mezei, T. Cserfalvi*, M. Jánossy: Pressure Dependence of the Atmospheric Electrolyte Cathode Glow Discharge Spectrum. J. Anal. Atm. Spectr. 12, 1203 (1997)
N. Kroó, W. Krieger, Z. Lenkefi, Z. Szentirmay, J. P. Thost, H. Walther: A new optical method for investigating of thin metal films. Surf. Sci. 331-333, 1305 (1995)
A. Hornsteiner, W. Krieger, Z. Szentirmay, N. Kroó, H. Walther: Images of surface plasmons at 1064 nm obtained with STM. In: Photons and Local Probes. Eds: O. Marti and R. Möller, Kluwer Acad. Publ. 251 (1995)
A. Hoffman, N. Kroó, Z. Lenkefi, Z. Szentirmay: A high precision ATR study of surface plasmon mediated reflectance in noble metal films. Surf. Sci. 352-354, 1043 (1996)
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Last modification: 2009-02-09 13:42:42
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Departments > Laser Physics
