A5004406863- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Laser-Plasma Interactions and Diagnostics
- Terahertz technology and applications
- Spectroscopy and Laser Applications
- Laser-induced spectroscopy and plasma
- Spectroscopy and Quantum Chemical Studies
- Photonic Crystal and Fiber Optics
- Solid State Laser Technologies
- Mass Spectrometry Techniques and Applications
- Semiconductor Quantum Structures and Devices
- Gyrotron and Vacuum Electronics Research
- Laser Design and Applications
- Advanced Fiber Optic Sensors
- Spectroscopy Techniques in Biomedical and Chemical Research
- Atmospheric and Environmental Gas Dynamics
- Advanced X-ray Imaging Techniques
- Atmospheric chemistry and aerosols
- Quantum optics and atomic interactions
- Atomic and Molecular Physics
- Orbital Angular Momentum in Optics
- Laser Material Processing Techniques
- Photonic and Optical Devices
- CCD and CMOS Imaging Sensors
- Nanowire Synthesis and Applications
TU Wien
2016-2025
University of Vienna
2021-2024
Christian Doppler Laboratory for Thermoelectricity
2021-2022
National Research Council Canada
2021
Abstract Extreme nonlinear interactions of THz electromagnetic fields with matter are the next frontier in optics. However, reaching this free space is limited by existing lack appropriate powerful sources. Here, we experimentally demonstrate that two-color filamentation femtosecond mid-infrared laser pulses at 3.9 μm allows one to generate ultrashort sub-cycle sub-milijoule energy and conversion efficiency 2.36%, resulting field amplitudes above 100 MV cm −1 . Our numerical simulations...
Abstract The physics of strong-field applications requires driver laser pulses that are both energetic and extremely short. Whereas optical amplifiers, parametric, boost the energy, their gain bandwidth restricts attainable pulse duration, requiring additional nonlinear spectral broadening to enable few or even single cycle compression a corresponding peak power increase. Here we demonstrate, in mid-infrared wavelength range is important for scaling ponderomotive energy interactions, simple...
This article provides an overview of laser-based absorption spectroscopy applications and discusses the parameter space requirements laser systems for each these applications, with a special emphasis on frequency comb systems. We walk reader through basics spectroscopy, review common line-broadening mechanisms as fundamental challenges to precision look into established solutions, introduce frequency-comb-based suggest novel approach broadband in mid-infrared spectral region based...
Filamentation-assisted pulse compression in the gas phase is shown to enable generation of subterawatt few-cycle pulses mid-infrared (mid-IR). With both spatial modulation instabilities and excessive plasma scattering mid-IR beam prevented through a careful choice pressure input peak power, providing single-filament regime propagation, powers as high 0.3 TW are achieved truly single-mode, almost diffraction-limited 35 fs output at central wavelength 4 μm. Applications molecular spectroscopy,...
We identify and experimentally demonstrate a physical scenario whereby high-peak-power mid-infrared (mid-IR) pulses can be compressed as part of their free-beam spatiotemporal evolution within the regions anomalous dispersion in air to yield few-cycle subterawatt field waveforms. Unlike filamentation-assisted pulse compression, pulse-compression identified this work does not involve any noticeable ionization air, enabling whole-beam self-compression mid-IR laser without ionization-induced...
We report on, to the best of our knowledge, first results laser plasma wakefield acceleration driven by ultrashort mid-infrared (IR) pulses (λ=3.9 μm, 100 fs, 0.25 TW), which enable near- and above-critical density interactions with moderate-density gas jets. Relativistic electron up ∼12 MeV occurs when jet width exceeds threshold scale length for relativistic self-focusing. present scaling trends in accelerated beam profiles, charge, spectra, are supported particle-in-cell simulations...
Tailoring the properties of driving laser to need applications often requires compromises among stability, high peak and average power levels, pulse duration, spectral bandwidth. For instance, spectroscopy with optical frequency combs in extreme/visible ultraviolet region a near-IR laser, therefore power, duration few tens fs, maximal available Contrarily, parametric conversion efficiency is higher for pulses 100-fs range due temporal walk-off coating limitations. Here we suggest an approach...
Properties of filaments ignited by multi-millijoule, 90 fs mid-infrared pulses centered at 3.9 μm are examined experimentally monitoring plasma density, losses, spectral dynamics and beam profile evolution different focusing strengths. By changing from strong (f=0.25 m) to loose (f=7 focusing, we observe a shift plasma-assisted filamentation with low density. In the latter case, manifests itself self-symmetrization spatial self-channeling. Spectral in case is dominated nonlinear Raman...
Dual-comb (DC) ranging is an established method for high-precision and high-accuracy distance measurements. It is, however, restricted by inherent length ambiguity the requirement complex control loops comb stabilization. Here, we present a simple approach expanding ambiguity-free measurement of dual-comb exploiting intrinsic intensity modulation single-cavity dualcolor DC simultaneous time-of-flight nd D C This enables distances up to several hundred km with precision accuracy dualcomb...
Formation of light bullets-tightly localized in space and time packets, retaining their spatiotemporal shape during propagation-is, for the first time, experimentally observed investigated a new regime mid-infrared filamentation ambient air. It is suggested that bullets generated air by multi-mJ, positively chirped 3.9-μm pulses originate from dynamic interplay between anomalous dispersion vicinity CO2 resonance positive chirp, both intrinsic, carried driver pulse, accumulated, originating...
The generation of high order harmonics from femtosecond mid-IR laser pulses in ZnO has shown great potential to reveal new insight into the ultrafast electron dynamics on a few timescale. In this work we report experimental investigation photoluminescence and high-order harmonic (HHG) single crystal polycrystalline thin film irradiated with intense pulses. ellipticity dependence HHG process is experimentally studied up 17th for various driving wavelengths spectral range 3–4 µm. Interband...
We report on experimental results in a new regime of relativistic light-matter interaction employing mid-infrared (3.9-micrometer wavelength) high-intensity femtosecond laser pulses. In the generated plasma, electrons reach energies already at rather low intensities due to fortunate lambda^2-scaling kinetic energy with wavelength. The lower intensity suppresses optical field ionization and creation pre-plasma rising edge pulse efficiently, enabling an enhanced efficient vacuum heating...
Intense laser fields focused into ambient air can be used to generate high-bandwidth current densities in the form of plasma channels and filaments. Excitation with bichromatic enables us adjust amplitude sign these currents using relative phase between two light pulses. Two-color filamentation gas targets provides a route scaling energy terahertz pulses microjoule levels by driving channel high-energy source. However, structure is highly susceptible drifts both other parameters, making...
We report here on results of systematic experimental-theoretical investigation high-order harmonic generation (HHG) in layers CdSe semiconductor quantum dots different sizes and a reference bulk thin film. observe strong decrease the efficiency, up to complete suppression HHG with energies quanta above band gap for smallest dots, whereas intensity below harmonics remains weakly affected by dot size. In addition, it is observed that enhanced increasing driving wavelength. These investigations...
We present experimental studies of long-distance transmission ultrashort mid-infrared laser pulses through atmospheric air, probing air dispersion in the 3.6-4.2-μm wavelength range. Atmospheric is still highly transparent to electromagnetic radiation this spectral region, making it interesting for signal transmission. However, unlike most high-transmission regions gas media, group-velocity dispersion, as we show work, anomalous at these wavelengths due nearby asymmetric-stretch...
Since its first demonstration, laser induced aerosol formation (LIAF) has been studied in various environmental conditions and parameters. LIAF driven by UV near-IR lasers mainly relies on the nitrogen photo-oxidative chemistry, leading to production of hygroscopic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mi mathvariant="normal">H</mml:mi> mathvariant="normal">N</mml:mi> mathvariant="normal">O</mml:mi>...
In this work, we introduce a simplified approach to efficiently extend the high harmonic generation (HHG) cutoff in gases without need for laser frequency conversion via parametric processes. Instead, employ postcompression and red-shifting of Yb:CaF2 stimulated Raman scattering (SRS) nitrogen-filled stretched hollow core fiber. This driving scheme circumvents low-efficiency window amplifiers 1100–1300 nm range. We demonstrate being suitable upscaling power driver with an optimal wavelength...
Einstein established the quantum theory of radiation and paved way for modern laser physics including single-photon absorption by charge carriers finally pumping an active gain medium into population inversion. This can be easily understood in particle picture light. Using intense, ultrashort pulse lasers, multiphoton has been realized. In this nonlinear interaction regime, excitation inversion depend not only on photon energy but also intensity incident light, which still described solely...
The introduction of mid-IR optical parametric chirped pulse amplifiers has catalyzed interest in multimillijoule, infrared femtosecond pulse-based filamentation. As tunneling ionization is a fundamental first stage these high-intensity laser-matter interactions, characterizing the process critical to understand derivative topical studies on filamentation and self-focusing. Here, we report direct nonintrusive measurements total electron count number densities generated at 3.9...
We demonstrate, strong THz emission from two-color mid-infrared (3.9 μm) femtosecond laser filaments. The conversion efficiency approaches the percent level, at least one order of magnitude higher than previously reported for plasma-based sources.
Ultrafast coherent phonon dynamics in ZnO is studied via high-order harmonic generation by intense mid-IR laser pulses. We show, the dynamic very different after excitation tunnel and multiphoton regime.