Janos Hebling

Janos Hebling
University of Pécs | PTE · Institute of Physics

Prof

About

269
Publications
24,600
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
6,640
Citations

Publications

Publications (269)
Article
A novel THz source, based on optical rectification in LiNbO3 using the tilted-pulse-front technique, is proposed and experimentally demonstrated. The pulse-front tilt is introduced by a volume phase holographic grating, efficiently used at perpendicular incidence in transmission, and the THz pulses are produced in a LiNbO3 plane-parallel nonlinear...
Article
Tilted-pulse-front-pumping (TPFP) lithium-niobate terahertz (THz) pulse sources are widely used in pump-probe and control experiments since they can generate broadband THz pulses with tens of microjoules of energy. However, the conventional TPFP setup suffers from limitations, hindering the generation of THz pulses with peak electric field strength...
Article
Full-text available
The transmission of THz, near-infrared (1030 nm), and green (515 nm) pulses through Eisenia andrei body wall is studied, which consists of epithelial layer and circular and longitudinal muscles. Samples with the full-body cross-section were also investigated. The transmitted power for the green pulses followed the Beer-Lambert law of exponential at...
Article
Full-text available
A THz-pulse-driven compact, < 150 mm in total length, two-stage electron accelerator setup was designed. It uses 2 × 2 pairs of nearly counter-propagating focused THz pulses. The effects of the initial bunch charge and the propagation direction of the THz pulses on the energy of the accelerated electrons were investigated by numerical simulations....
Article
Full-text available
Terahertz (THz) irradiation of excised Eisenia andrei earthworms is shown to cause overriding the genetically determined, endogenously mediated segment renewing capacity of the model animal. Single-cycle THz pulses of 5 µJ energy, 0.30 THz mean frequency, 293 kV/cm peak electric field, and 1 kHz repetition rate stimulated the cell proliferation (in...
Article
Amplified bursts of laser pulses are sought for various machining, deposition, spectroscopic, and strong-field applications. Standard frequency- and time-domain techniques for pulse division become inadequate when intraburst repetition rates reach the terahertz (THz) range as a consequence of inaccessible spectral resolution, requirement for interf...
Article
Intensity-dependent effective four-photon absorption (4PA) coefficients in GaP and ZnTe semiconductors were measured by the z-scan method using pump pulses of 1.75 µm wavelength, 135 fs duration, and up to 500 GWcm-2 intensity. A nonlinear pulse propagation model, including linear dispersion and 4PA was used to obtain the 4PA coefficients from meas...
Preprint
Full-text available
High energy single- to few-cycle terahertz pulses enable the exploration of the frontier of science, such as electron acceleration, strong-field physics, and spectroscopy. One important method of generating such terahertz pulses is to use the tilted-pulse-front (TPF) technique. However, due to the non-collinear phase-matching, the large angular dis...
Article
Terahertz time-domain spectroscopy measurements were performed on 0.7 mol% Mg-doped stoichiometric lithium niobate crystal with ordinary and extraordinary polarization in the 4-460 K temperature range. The absorption coefficient and refractive index spectra were recorded in the terahertz frequency range from 0.5 to 1.8 THz. The data extracted from...
Conference Paper
The absorption coefficient and refractive index spectra of 0.7 mol% Mg-doped stoichiometric lithium niobate were determined in the terahertz frequencies. The phase-matching parameters extracted from time-domain measurements were given in a wide temperature range.
Conference Paper
Effective four-photon absorption coefficients and their anizotropy were meas-ured in semiconductors (ZnTe, GaP) by z-scan technique in infrared wavelength.
Conference Paper
Three new-generation terahertz sources are presented. These setups can solve the problems of energy-scalability and pulse-homogeneity. More than 15-mJ THz energy is predicted, nearly two orders of magnitudes higher than has been achieved earlier.
Conference Paper
Acceleration of ions by Coulomb explosion following ripping the electrons from gas plasmas by ultrafast standing waves are numerically investigated. Generation with 1.3 % efficiency of sub-MeV energy deuterons with 0.8 nC bunch charge is predicted.
Conference Paper
Simulations of contact grating design parameters in the wavelength range of 1.76-3.9 µm are presented for gallium arsenide and gallium phosphide. Diffraction efficiencies as high as 80% and 90% have been achieved in GaAs and GaP respectively.
Article
Full-text available
A tilted-pulse-front pumped terahertz pulse source is proposed for the generation of extremely high field single-cycle terahertz pulses. The very simple and compact source consists of a single crystal slab having a blazed reflection grating grooved in its back surface. Its further important advantages are the energy scalability and the symmetric TH...
Article
Full-text available
Terahertz (THz) light has proven to be a fine tool to probe and control quasi-particles and collective excitations in solids, to drive phase transitions and associated changes in material properties, and to study rotations and vibrations in molecular systems. In contrast to visible light, which usually carries excessive photon energy for collective...
Preprint
Full-text available
A tilted-pulse-front pumped terahertz pulse source is proposed for the generation of extremely high field single-cycle terahertz pulses. The very simple and compact source consists of a single crystal slab having a blazed reflection grating grooved in its back surface. Its further important advantages are the energy scalability and the symmetric TH...
Article
Recently a hybrid-type terahertz (THz) pulse source was proposed for high energy terahertz pulse generation. It is the combination of the conventional tilted-pulse-front setup and a nonlinear crystal with a transmission stair-step echelon of period in the hundred-micrometer range etched into the front face. The tilt angle introduced by the conventi...
Article
A new type of tilted-pulse-front pumped terahertz (THz) source has been demonstrated, which is based on a LiNbO3plane-parallel slab with an echelon structure on its input surface. Single-cycle pulses of 1 μJ energy and 0.30 THz central frequency have been generated with 5×10−4 efficiency from such a source. One order-of-magnitude increase in effici...
Article
Full-text available
THz pulse generation in a nonlinear optical slab with an entrance surface having an echelon structure is demonstrated. The setup uses a transmission grating and a planeparallel lithium-niobate crystal slab, and ensures a good-quality, symmetric THz beam and enables scalability to high pulse energies.
Conference Paper
Intensity-dependent four-photon absorption coefficients of Gallium-Phosphide (GaP) and Zink-Telluride (ZnTe) have been measured by the z-scan method at 1.75 μm pump wavelength. Anisotropy in the effective four-photon absorption has been shown in GaP.
Conference Paper
Novel compact LiNbO3 and semiconductor THz sources, based on the tilted-pulse-front technique, enable straightforward scaling to unprecedented focused field strengths up to 50 MV/cm in the low-frequency part of the THz spectrum.
Article
Research at modern light sources continues to improve our knowledge of the natural world, from the subtle workings of life to matter under extreme conditions. Free-electron lasers, for instance, have enabled the characterization of biomolecular structures with sub-ångström spatial resolution, and paved the way to controlling the molecular functions...
Article
Controlling light polarization is one of the most essential routines in modern optical technology. Since the demonstration of optical pulse shaping by spatial light modulators and its potential in controlling the quantum reaction pathways, it paved the way for many applications as a coherent control of the photoionization process or as polarization...
Article
Full-text available
Practical aspects of the robust method we proposed for producing few-cycle attosecond pulses with arbitrary waveform in the extreme ultraviolet spectral range are studied numerically. It is based on the undulator radiation of relativistic ultrathin electron layers produced by laser-driven energy modulation. By using realistic specifications, we sho...
Article
Full-text available
A relativistic electron source is proposed, driven by the wakefield of an intense terahertz (THz) pulse in low-density gas plasma. In contrast to the optical and near-infrared regimes, the low (3.5 THz) frequency and the long (λ T = 85.6 μm) wavelength of the THz pulse offers distinct advantages, such as the -scaling of the electron ponderomotive e...
Article
Full-text available
The production of intense attosecond light pulses is an active area in accelerator research, motivated by the stringent demands of attosecond science: (i) short pulse duration for resolving the fast dynamics of electrons in atoms and molecules; (ii) high photon flux for probing and controlling such dynamics with high precision. While the free-elect...
Preprint
A new type of tilted-pulse-front pumped terahertz (THz) source has been demonstrated, which is based on a lithium niobate plane-parallel slab with an echelon structure on its input surface. Single-cycle pulses of 1 microjoule energy and 0.30 THz central frequency have been generated with 0.05% efficiency from such a source. One order-of-magnitude i...
Article
Full-text available
The acceleration of single electrons and electron bunches by focused THz pulse pairs has been investigated by numerical simulations. The effect of the choice of the beam waist radius, the carrier-envelope phase, and the propagation direction of the THz pulses on the energy of the accelerated electrons was investigated. The acceleration of electron...
Article
Full-text available
Multicycle THz pulse generation by optical rectification in GaP semiconductor nonlinear material is investigated by numerical simulations. It is shown that GaP can be an efficient and versatile source with up to about 8% conversion efficiency and a tuning range from 0.1 THz to about 7 THz. Contact-grating technology for pulse-front tilt can ensure...
Poster
Applying a standard earthworm tail segment regeneration model the effects of THz pulses were investigated on the segment formation kinetic and characteristic histological alterations in Eisenia Andrei after 25 tail segments removal. After the surgical intervention, the last 4-5 segments located close to the transection were exposed to THz pulses wi...
Article
This issue features papers from the Extreme Light Infrastructure (ELI) project and expanded papers based on results presented at the 6th International Conference on Attosecond Physics (ATTO 2017), as well as contributions from the broader international community on the attosecond science and technology.
Article
Full-text available
We develop a method for mapping the anharmonic lattice potential using the time-dependent electric field of the transmitted pulse through thin sample supported by a substrate of non-negligible thickness. Assuming linear propagation in the substrate we fully take into account internal reflection in it while the sample can show arbitrary nonlinear re...
Conference Paper
Because of their suitable wavelength and temporal period, THz pulses with extremely high field strength are ideal for driving particle accelerators. Here we give an overview of the possibilities and challenges of THz-pulse-driven electron post accelerators.
Conference Paper
A monolithic contact-grating semiconductor source and a hybrid LiNbO3 stair-step echelon are presented for efficient THz pulse generation by optical rectification. They enable excellent focusability of the THz beams and are scalable to mJ-level THz pulse energies.
Conference Paper
A laser-plasma accelerator based carrier-envelope-phase stable attosecond source is investigated numerically. Pulses with tens-of-nJ energy and 90 to 240 attosecond duration are predicted in the 30-120 nm wavelength range.
Conference Paper
DC-OPA is proposed for generation of periodically intensity-modulated-pulses by interference of the signal and the idler. These pulses allows to tunable THz-pulse generation by the chirp and the delay between the pump and the signal.
Conference Paper
According to calculations, single-cycle attosecond pulses can be generate with few nJ energy by Thomson scattering of terahertz pulse on ultrathin electron layer, produced by a laser-plasma wakefield accelerator and some suitable magnetic devices.
Conference Paper
Up to 5% conversion efficiency is predicted by numerical simulations for optimized GaP contact-grating THz sources based on optical rectification. Easy control of multicycle THz waveforms is enabled by a flexible dual-chirped OPA pump source.
Conference Paper
A nonlinear echelon slab structure is proposed for high-energy THz pulse generation. The most important advantage of the setup is the possibility of using plane parallel nonlinear optical crystal for producing good-quality, symmetric THz beam.