Karoly Osvay - Academia.edu (original) (raw)

Papers by Karoly Osvay

Az ultrarövid, 100 fs hosszú fényimpulzusokat előállító lézerek 90-es évek elején, a 10 fs és röv... more Az ultrarövid, 100 fs hosszú fényimpulzusokat előállító lézerek 90-es évek elején, a 10 fs és rövidebb impulzusú lézerek a 90-es évek második felében kezdődött, napjainkban is gyorsuló elterjedésével egyre nő az érdeklődés az anyagok lineáris illetve nemlineáris optikai tulajdonságainak minél teljesebb ismerete iránt. A pályázat keretein belül végrehajtott kutatások jelentős része különböző nemlineáris optikai kísérleteken alapul, a kétfotonos abszorpciós együttható mérésétől kezdve a porcelánok roncsolási tartományának megállapításáig. Külön említést érdemel a lineáris femtoeszekundumos mérési módszer kifejlesztése illetve az annak segítségével végzett nagy pontosságú diszperziómérés és törésmutató meghatározás. A femtoszekundumos fényforrásokkal és mérésekkel kapcsolatosan végzett további kutatásainkból kiemelendő az ultrarövid impulzusok hordozó-burkoló fázis csúszásának (CEP csúszás) mérésére kidolgozott egyedülállóan új, lineáris eljárás. A kutatás során a pályázatban eredetile...

CLEO/Europe. 2005 Conference on Lasers and Electro-Optics Europe, 2005.

To measure the pressure dependence of dispersion, the Mach-Zender interferometer illuminated by 8... more To measure the pressure dependence of dispersion, the Mach-Zender interferometer illuminated by 800nm, 16 fs pulses from a Ti:S oscillator working at 71 MHz repetition rate. The outcoming pulses from both arms were unified and sent to the entrance slit of an imaging spectrograph. The spectrally resolved interference fringes were then captured and evaluated, which provides directly the values of GDD, TOD and even higher order dispersion terms. When the tube was in air, the evaluation of the fringes provided the base dispersion values. Starting evacuating the tube, the spectrally resolved fringes were captured again at certain pressures. The dispersion falls exponentially with an exponent of 0.00149 mbar-1 but still exhibits a surprisingly high value of 4.7 fs2/m at more than four order of magnitude lower level than the standard pressure. The air conditioning system maintained constant the room temperature at 23 °C and the relative humidity at 60 %.

Ultrashort Wavelength Lasers II, 1994

ABSTRACT An injector-amplifier architecture for XUV lasers has been developed and demonstrated us... more ABSTRACT An injector-amplifier architecture for XUV lasers has been developed and demonstrated using the Ge XXIII Collisional laser. Results are described for injection into single and double plasma amplifiers. Prismatic lens-like and higher order aberrations in the amplifier are considered. Limitations on ultimate brightness are discussed and also scaling to operation at shorter wavelengths. A preliminary study has been made of UV multiphoton ionisation using 300 fs pulses at high intensity

Optical and Quantum Electronics, 1996

A method is proposed for relaxing the bandwidth restrictions due to dispersion in frequency mixin... more A method is proposed for relaxing the bandwidth restrictions due to dispersion in frequency mixing. An example for the third-harmonic generation of neodymium glass shows that it is possible to significantly reduce and even eliminate the effects of dispersion for the bandwidths required for femtosecond pulses.

IEEE Journal of Selected Topics in Quantum Electronics, 2004

Applied Physics Letters, 2002

Femtosecond pulses at 400 nm were amplified using a noncollinear optical parametric amplifier pum... more Femtosecond pulses at 400 nm were amplified using a noncollinear optical parametric amplifier pumped by picosecond pulses at 267 nm. A flat spectral gain exceeding 3500 was achieved in single pass within the available 17 nm bandwidth of the signal pulse. The effect of pump depletion, group delay difference, and the geometry of the interacting pulses on the spectral gain are also investigated.

International Conference on Lasers, Applications, and Technologies 2007: High-Power Lasers and Applications, 2007

A laser scheme implementing a combination of negatively- and positively-chirped pulse amplificati... more A laser scheme implementing a combination of negatively- and positively-chirped pulse amplification (NPCPA) is demonstrated. This method of amplification suppresses spectral narrowing typically appearing in chirped pulse amplification (CPA) lasers thus supports pulse spectrum substantially broader than a conventional CPA. With a NPCPA Ti:sapphire laser we have achieved laser pulses of 50 nm spectral width and 150 mJ energy without any additional spectral correction. The scheme appears as an easy and reliable solution to preserve spectral bandwidth in Ti:Sapphire lasers, especially at Petawatt and higher power levels.

Journal of the Optical Society of America B, 2018

Springer Series in Chemical Physics, 2001

Journal of Electron Spectroscopy and Related Phenomena, 2015

OPTIKA '98: 5th Congress on Modern Optics, 1998

ABSTRACT

Conference on Lasers and Electro-Optics 2012, 2012

ABSTRACT A novel and robust technique for single shot measurement of angular dispersion across th... more ABSTRACT A novel and robust technique for single shot measurement of angular dispersion across the entire laser beam is introduced. The capabilities are demonstrated with the alignment of the grating compressor of a CPA laser.