A5089732432- Orbital Angular Momentum in Optics
- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Laser Material Processing Techniques
- Laser-induced spectroscopy and plasma
- Photonic and Optical Devices
- Nonlinear Optical Materials Studies
- Advanced Optical Imaging Technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Nonlinear Photonic Systems
- Laser-Plasma Interactions and Diagnostics
- Random lasers and scattering media
- Photorefractive and Nonlinear Optics
- Microfluidic and Bio-sensing Technologies
- Near-Field Optical Microscopy
- Spectroscopy and Laser Applications
- Laser Design and Applications
- Advanced Fluorescence Microscopy Techniques
- Optical Coatings and Gratings
- Nanofabrication and Lithography Techniques
- Terahertz technology and applications
- Optical Wireless Communication Technologies
- Digital Holography and Microscopy
- Optical Coherence Tomography Applications
- Surface Roughness and Optical Measurements
Foundation for Research and Technology Hellas
2015-2024
University of Crete
2015-2024
FORTH Institute of Electronic Structure and Laser
2002-2023
Aristotle University of Thessaloniki
1996-2019
National Technical University of Athens
2008
We report on the experimental observation of abruptly autofocusing waves. This interesting family wave packets has been realized by using a radially symmetric Airy intensity distribution. As demonstrated in our experiments, these waves can exhibit unusual features, such as ability to autofocus following parabolic trajectory toward their focus.
We demonstrate the realization of intense Airy-Airy-Airy (${\mathrm{\text{Airy}}}^{3}$) light bullets by combining a spatial Airy beam with an pulse in time. The ${\mathrm{\text{Airy}}}^{3}$ belong to family linear spatiotemporal wave packets that do not require any specific tuning material optical properties for their formation and withstand both diffraction dispersion during propagation. show are robust up high intensity regime, since they capable healing nonlinearly induced distortions profile.
Abstract We propose in this White Paper a concept for space experiment using cold atoms to search ultra-light dark matter, and detect gravitational waves the frequency range between most sensitive ranges of LISA terrestrial LIGO/Virgo/KAGRA/INDIGO experiments. This interdisciplinary experiment, called Atomic Experiment Dark Matter Gravity Exploration (AEDGE), will also complement other planned searches exploit synergies with wave detectors. give examples extended sensitivity matter offered...
Tunable-ring Airy beams are experimentally generated and employed for the fabrication of large three-dimensional structures with high resolution using multi-photon polymerization. We demonstrate that these can be adjusted to abruptly autofocus over an extended range working distances while keeping their voxel shape dimensions almost invariant. This striking property together real-time electronically controlled focus tuning makes ideal candidates long-range Moreover, well-controlled remote...
We demonstrate the existence of an additional class stationary accelerating Airy wave forms that exist in presence third-order (Kerr) nonlinearity and nonlinear losses. Numerical simulations experiments, agreement with analytical model, highlight how these solutions sustain evolution beams. The generic nature solution allows extension results to other settings, a variety applications are suggested.
The nonlinear dynamics of intense truncated Airy beams in Kerr ionizing media are investigated from numerical simulations and experiments. We show numerically that a competition between the linear effects takes place may be modified by tuning width main lobe beam size truncating diaphragm. Our analysis shows acceleration peak, an inherent feature propagation, is preserved only for powers below certain threshold. Nonlinear propagation with low power sustained continuous energy flux its...
We report the near through mid-infrared (MIR) optical absorption spectra, over range 0.05–1.3 eV, of monocrystalline silicon layers hyperdoped with chalcogen atoms synthesized by ion implantation followed pulsed laser melting. A broad band emerges, peaking 0.5 eV for sulfur and selenium 0.3 tellurium samples. Its strength width increase impurity concentration. decreases markedly subsequent thermal annealing. The emergence a MIR is consistent formation an from isolated deep donor levels as...
Developing coherent intense broadband light sources is undoubtedly one of the key elements in pushing frontiers optical sciences, especially those nonlinear terahertz (THz) optics. Plasma-based THz emitters excel many aspects thanks to their broad radiation bandwidth, high output pulse energy and immunity power damage. Various excitation wavelengths gases have been explored search for a stronger wave emission from laser-induced plasmas, whereas few attempts made with artificially modulated...
We show that light spiraling like a tornado can be generated by superimposing abruptly auto-focusing ring-Airy beams carry orbital angular momentum of opposite handedness. With different parabolic propagation trajectories, the are tailored to auto-focus at overlapping focal regions. This results in complex wave with intense lobes twist and shrink an accelerating fashion along propagation. By achieving acceleration values exceed <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Recent developments in quantum technology have resulted a new generation of sensors for measuring inertial quantities, such as acceleration and rotation. These can exhibit unprecedented sensitivity accuracy when operated space, where the free-fall interrogation time be extended at will environment noise is minimal. European laboratories played leading role this field by developing concepts tools to operate these relevant environment, parabolic flights, towers, or sounding rockets. With...
This Letter demonstrates a laser rapid prototyping method that can be used for fabricating high-density resolution patterns of biomaterials. Ultraviolet femtosecond pulses have been directly printing wide range biomaterials in complicated and structures. The ultrashort reduce the thermal effects, thus allowing effective deposition sensitive at high spatial microfabricating patterns. We present microprinting different biomaterial patterns, such as DNA (deoxyribonucleic acid) proteins, with...
Optical aberrations are usually considered a drawback in optical systems. Here we show that through them net cubic phase modulation can be imprinted on the wave front of light beam, which after spatial Fourier transformation creates Airy beams. Experiments and supporting simulations demonstrate appropriately adjusted cylindrical lenses produce both one- two-dimensional tunable The use simple elements makes approach attractive convenient for generating intense femtosecond beams filaments....
The description of ultrashort laser pulse filamentation in condensed media as a spontaneous formation X waves is shown to apply also filaments generated air. Within this framework, simple explanation brought for several features the filament such subdiffractive propagation and energy flux from weakly localized tails X-waves intense core.
In this letter we consider the effect of laser pulse duration on surface morphology and field emission properties silicon structured by UV pulses. three different regimes ranging from sub-ps to ns, altered fabricated microspike arrays. The arrays were influenced morphological changes exhibiting a reduction threshold 2.5V∕μm for 15ns ability tuning laser-fabricated makes them excellent candidates use as cathodes.
A powerful experimental method, based on holographic microscopy, is used to retrieve the spatiotemporal distribution of small (&lt;10−3) refractive index perturbations induced by ultrafast laser pulses in transparent media. numerical iterative wavefront propagation approach accurately reconstruct both phase and amplitude perturbed probe beam wavefront, while Abel inversion recovers exact three dimensional perturbation. For demonstration, a filament plasma string air fully characterized.
We study, both experimentally and theoretically, the underlying physics of third-harmonic generation in air by a filamented infrared femtosecond laser pulse propagating through thin plasma channel. It is shown that recently observed more than two-order-of-magnitude increase efficiency occurs due to plasma-enhanced third-order susceptibility. An estimate effective value this susceptibility given.
We show that high-angle Bessel beams may significantly reduce nonlinear pulse distortions due, for example, to Kerr effects (self-phase-modulation and self-focusing) yet enhance ionization plasma generation. Holographic reconstruction of in water intensity clamping at increased intensities evidence nontrivial dynamics as the input energy is increased. The solvated electron density increases cavitation-induced bubbles are ejected from focal region indicating a significant excess heating...
A three-dimensional (3D) holographic focal volume engineering method is proposed and employed for advanced multiphoton polymerization. large number of foci are closely positioned in space according to a designed geometry, avoiding undesired interference effects by phase engineering. Through all-optical micro-displacements space, the discrete bundle leads realization complete 3D arbitrary structures. The microstructures fabricated direct laser writing without additional optical or mechanical...
The creation of volume plasma density gratings in air by temporally overlapped high-intensity IR femtosecond laser pulses is demonstrated experimentally. Through the diffraction various probe beams grating properties are recovered including its thickness and refractive index modulation, as well decay dynamics. these photonic devices suggest that they can be used applications involving high intensity lasers, such filamentation, where no physical objects placed path beams.
Growth of SnSe structures by the ALD method using Et4Sn and H2Se as precursors has been investigated. It was established that coverage occurs at a temperature above 250 °C morphology layer depends on temperature. At 350 we have grown sphere-shaped particles 100–200 nm in diameter completely covering substrate one monolayer. For samples 450 petal-shaped crystal islands were observed. The IR spectrum shows small shift (∼0.20 eV) room-temperature band gap energy.
The process of third-harmonic generation during the filamentation intense IR femtosecond laser pulses in air is investigated experimentally. It shown that introduction a thin plasma string created by another pulse, perpendicularly to filament's path, dramatically reshapes beam into Bessel-like far-field distribution, while at same time significantly enhances, up 250 times, its conversion efficiency.
We demonstrate both theoretically and experimentally that the harmonics from abruptly auto-focusing ring-Airy beams present a surprising property, they preserve phase distribution of fundamental beam. Consequently, this "phase memory" inherits to abrupt autofocusing behavior, while, under certain conditions, their foci coincide in space with one fundamental. Experiments agree well our theoretical estimates detailed numerical calculations. Our findings open way for use such strong field science.
We show the existence of a family waves that share common interesting property affecting way these propagate and focus. The are superposition twin waves, which conjugate to each other under inversion propagation direction. In analogy holography, "real" "virtual" related, respectively, converging diverging parts beam can be clearly visualized in real space at two distinct foci action focusing lens. Analytic formulas for intensity distribution after derived, while numerical experimental...
We recently introduced a new class of optical beams with Bessel-like transverse profile and increasing beam width during propagation, akin to an “inverted pin.” Owing their specially engineered distribution, these have shown remarkable performance in atmospheric turbulence. Specifically, inverted pin (PBs) were found reduced scintillation index as compared collimated or focused Gaussian well other types especially moderate strong In this work, we demonstrate that carrying orbital angular...