2024-03-28T23:56:44Z
https://zenodo.org/oai2d
oai:zenodo.org:10149008
2023-11-17T11:42:58Z
user-laserlab
user-eu
Marcek Chorvatova, Alzbeta
Uherek, Martin
Sigmundova, Ivica
Magdolen, Peter
Chorvat, Dusan
2020-02-14
<p>Our contribution is focused on broadening of the spectrum of available non-linear optical (NLO)-phores (contrast agents for nonlinear optical microscopy) by design and synthesis of new organic dyes with appropriate optical properties. One of the main pre-requisites of microscopy utilizing non-linear excitation is the existence of molecules that are able to provide NLO response for the second-harmonic generation (SHG) or for the two-photon excited fluorescence (TPEF). Many molecules naturally occurring in living tissue such as collagens or NAD(P)H were successfully used in this regard, but there is a natural interest in broadening of the spectrum of available NLO-phores. Gathered results confirm applicability of the newly synthesized dyes as new potential NLO-phores for confocal laser scanning microscopy with nonlinear excitation in rat aorta.</p>
https://doi.org/10.1117/12.2543350
oai:zenodo.org:10149008
eng
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Proc. SPIE 11244, Multiphoton Microscopy in the Biomedical Sciences XX, 1124410, (2020-02-14)
SPIE BiOS 2020, San Francisco, California, United States
SHG
NLO
2-photon excitation
fluorescence
non-linear
microscopy
benzobisthiazoles
aorta
Evaluation of newly synthesized potential NLO-phores for 2-photon and SHG imaging
info:eu-repo/semantics/article
oai:zenodo.org:7360565
2022-11-28T12:02:30Z
user-laserlab
user-eu
Mengots, Alvis
Hillers-Bendtsen, Andreas Erbs
Doria, Sandra
Ørsted Kjeldal, Frederik
Machholdt Høyer, Nicolai
Ugleholdt Petersen, Anne
Mikkelsen, Kurt V.
Di Donato, Mariangela
Cacciarini, Martina
Brøndsted Nielsen, Mogens
2021-06-06
<p>Photoswitch triads comprised of two dihydroazulene (DHA) units in conjugation to a central trans-azobenzene (AZB) unit were prepared in stepwise protocols starting from meta- and paradisubstituted azobenzenes. The para-connected triad had significantly altered optical properties and lacked the photoactivity of the separate photochromes. Instead, for the meta-connected triad all three photochromes could be photoisomerized to generate an isomer with two vinylheptafulvene (VHF) units and a cis-azobenzene unit. The photoisomerizations were studied by ultrafast spectroscopy, revealing a fast DHA-to-VHF photoisomerization and a slower trans-to-cis AZB photoisomerization. This meta triad underwent thermal VHF-to-DHA back-conversions with a similar rate of all VHFs, independent of the identity of the neighboring units, and in parallel thermal cis-to-trans AZB conversion. The experimental observations were supported by computations (excitation spectra and orbital analysis of the transitions).</p>
https://doi.org/10.1002/chem.202101533
oai:zenodo.org:7360565
eng
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Chemistry - A European Journal, 27(48), 12437–12446, (2021-06-06)
azo compounds
conjugation
electrocyclic reactions
isomers
photochromism
Dihydroazulene-Azobenzene-Dihydroazulene Triad Photoswitches
info:eu-repo/semantics/article
oai:zenodo.org:1117869
2020-01-20T14:52:39Z
user-laserlab
Le Marec Andréa
Larroche Olivier
Klisnick Annie
2017-12-18
<p>A quantitative interpretation method is described for experiments involving the linear autocorrelation of partially coherent extreme-ultraviolet (XUV) pulses, generated by either x-ray free-electron lasers or plasma-based XUV lasers. A recently published modeling method for partially coherent pulses is nu- merically implemented in that specific case. Analyt- ical expressions for the statistical root-mean-square average of the fringe visibility are derived. The method yields unambiguous information on both the coherence time and the pulse duration, providing a valuable data interpretation tool.</p>
https://doi.org/10.1364/OL.42.004958
oai:zenodo.org:1117869
eng
Zenodo
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coherence
free-electron lasers
interferometry
autocorrelation
X-ray lasers
ultra-short lasers
Linear autocorrelation of partially coherent extreme-ultraviolet lasers: a quantitative analysis
info:eu-repo/semantics/article
oai:zenodo.org:2669475
2020-01-20T16:40:48Z
user-laserlab
user-eu
Vaičaitis, Virgilijus
Balachninaitė, Ona
Morgner, Uwe
Babushkin, Ihar
2019-05-01
<p>We demonstrated terahertz (THz) radiation generated from a three-color laser-excited filament in air for a wide tuning range and various wavelength ratios of the pump laser pulses. As a pump source, the radiation of the femtosecond Ti:sapphire laser and infrared output of the optical parametric generator were used. It was found that the spectrum of generated THz pulses spans up to 50 THz, while the overall THz generation efficiency is of an order of magnitude larger than the one produced by two-color pulses in an analogous configuration. Our results support the idea that three-color pulses are more suitable for broadband THz generation, since the corresponding waveforms can produce faster free electrons in larger quantities. We have found that the conversion efficiency is significantly limited due to intensity clamping. The spectral broadening of THz radiation is explained by aperiodicity of ionization events in time.</p>
https://doi.org/10.1063/1.5078683
oai:zenodo.org:2669475
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Journal of Applied Physics, 125, 173103, (2019-05-01)
Electron density
Femtosecond lasers
Energy conversion efficiencies
Terahertz radiation
Chirped pulse amplification
Laser plasma interactions
Optical parametric amplifiers
Terahertz radiation generation by three-color laser pulses in air filament
info:eu-repo/semantics/article
oai:zenodo.org:3549606
2020-01-20T16:23:12Z
user-laserlab
user-eu
Mero, Mark
Wang, Li
Chen, Weidong
Ye, Ning
Zhang, Ge
Petrov, Valentin
Heiner, Zsuzsanna
2019-07-08
<p>The exceptional power scalability of Yb lasers has enabled the development of pulsed optical parametric amplifiers<br>
(OPA’s) operating at the short-wave edge of the mid-IR (MIR) with average powers beyond 10 W simultaneously<br>
providing peak powers in excess of 1 GW. Further wavelength extension into the longer-wave MIR is enabled by novel<br>
wide-bandgap non-oxide nonlinear crystals that can be pumped directly at 1 μm without detrimental one- and twophoton<br>
absorption of pump radiation. Eliminating the usual difference frequency generation step in producing MIR<br>
pulses above 5 μm could potentially increase the conversion efficiency of parametric down-conversion devices and<br>
enable a significant boost in the attainable average and peak power. Despite their utmost importance, material properties<br>
related to ultrafast laser-induced damage in nonlinear crystals are rarely investigated in the corresponding laser<br>
parameter range. In order to help unravel the complicated interplay of photorefractive effects, thermal lensing, and selffocusing/<br>
defocusing affecting the beam quality and catastrophic breakdown threshold in MIR OPA’s, we present the<br>
nonlinear index of refraction at 1 μm of KTiOAsO4, LiGaS2, and BaGa4S7. The reported data provide crucial design<br>
parameters for the development of high-average-power MIR OPA’s. As examples, (i) a 100-kHz, 1.55/3.1 μm dual-beam<br>
OPA delivering multi-GW peak power in each beam and a total average power of 55 W and (ii) a 100-kHz, sub-100-fs,<br>
1-μm-pumped OPA tunable in the 5.7-10.5-μm range are briefly presented.</p>
https://doi.org/10.1117/12.2540125
oai:zenodo.org:3549606
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Proc. SPIE, 11063, 1106307, (2019-07-08)
Nonlinear optical crystals
Laser-induced damage
Photorefractive damage
z-scan
nonlinear refractive index
KTiOAsO4 (KTA), LiGaS2 (LGS), BaGa4S7 (BGS)
Laser-induced damage of nonlinear crystals in ultrafast, high-repetitionrate, mid-infrared optical parametric amplifiers pumped at 1 μm
info:eu-repo/semantics/article
oai:zenodo.org:48776
2020-01-20T15:16:25Z
user-laserlab
user-eu
Sanchez, D.
Hemmer, M.
Baudisch, M.
Cousin, S.L.
Zawilski, K.
Schunemann, P.
Chalus, O.
Simon-Boisson, C.
Biegert, J.
2016-01-31
<p>We present a novel all-fiber pumped optical parametric chirped pulse amplifier (OPCPA) architecture to generate self-carrier-to-envelope-phase stable, sub-eight-optical-cycle duration pulses at 7 μm wavelength approaching millijoulelevel pulse energy at 100 Hz repetition rate. The system yields a peak power of 1.1 GW and, if focused to the diffraction limit, would reach a peak intensity of 7 × 1014 W∕cm2. The OPCPA is pumped by a 2 μm Ho:YLF chirped pulse amplifier to leverage the highly efficient and broadband response of the nonlinear crystal ZGP. The 7 μm seed at 100 MHz is generated via difference frequency generation from an Er:Tm:Ho multi-arm fiber frequency comb, and a fraction of its output optically injects the Ho:YLF amplifier. While the pulse bandwidth at 7 μm is perfectly suited for nonlinear and spectroscopic applications, current parameters offer, for the first time, to the best of our knowledge, the possibility to explore strong-field physics in an entirely new wavelength range with a ponderomotive force 77 times larger than from an 800 nm source. The overall OPCPA system is very compact and provides a new tool for investigations directly in the molecular fingerprint region of the electro-magnetic spectrum or to drive high harmonic generation to produce fully coherent x-rays in the multi-kiloelectron-volt range and possibly zeptosecond temporal waveforms.</p>
© 2016 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.
https://doi.org/10.1364/OPTICA.3.000147
oai:zenodo.org:48776
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Optica, 3(2), 147-150, (2016-01-31)
Infrared and far-infrared lasers
Parametric oscillators and amplifiers
Ultrafast lasers
7 μm, ultrafast, sub-millijoule-level mid-infrared optical parametric chirped pulse amplifier pumped at 2 μm
info:eu-repo/semantics/article
oai:zenodo.org:1164036
2020-01-20T16:28:53Z
user-laserlab
user-eu
Boursier, Elodie
Archipovaite, Giedre Marija
Delagnes, Jean-Christophe
Petit, Stéphane
Ernotte, Guilmot
Lassonde, Philippe
Segonds, Patricia
Boulanger, Benoît
Petit, Yannick
Légaré, François
Roshchupkin, Dmitry
Cormier, Eric
2017-09-15
<p>We demonstrate phase-matched difference frequency generation in the emerging nonlinear crystal La3Ga5.5Ta0.5O14. Tunable wavelengths between 1.4 and 4.7 μm are generated by using femtosecond sources. We also report on the measurements of the optical damage threshold in the femtosecond regime and on the nonlinear refractive index 𝒏2.</p>
https://doi.org/10.1364/OL.42.003698
oai:zenodo.org:1164036
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Optics Letters, 42(18), 3698-3701, (2017-09-15)
Nonlinear optics, materials
Nonlinear optics, parametric processes
Ultrafast lasers
Study of middle infrared difference frequency generation using a femtosecond laser source in LGT
info:eu-repo/semantics/article
oai:zenodo.org:888786
2020-01-20T15:42:34Z
user-laserlab
Hideghéty, Katalin
Brunner, Szilvia
Szabó, Zoltán Imre
Szabó Emília Rita
Polanek, Róbert
Tőkés, Tünde
2017-06-28
<p>Growing body of experimental and clinical evidence demonstrated the synergic effect between the rapidly implemented immunotherapy and advanced forms of focal radiotherapy, not only on the elimination of the irradiated lesion, but also on the enhancement the immune-mediated systemic anti-tumoral activity. It is essential for gaining the largest benefit from the combination of the two modalities to select the appropriate patients, to define the irradiation parameters, such as radiation quality (ie. particle) dosage, (total dose, fraction number) size of the target volume, the use of other supportive and anti-tumor drugs. In this review, we provide an update for the daily oncological practice on the data accumulated up to now on the molecular basis and patomechanism of enhancing radio-immune effect and clinical results, and highlight the most important parameters, which may increase the abscopal effect of ionizing radiation, thereby increasing the effectiveness of immunotherapy. However development of clinical guidelines for beneficial integration of immunotherapy and radiotherapy could be expected after evaluation the result of currently ongoing numerous (> 100) clinical trials. If the preclinical results will be confirmed clinically it could lead to paradigm shift in the use of ionizing radiation.</p>
https://doi.org/10.5281/zenodo.888786
oai:zenodo.org:888786
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https://doi.org/10.5281/zenodo.888785
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Klinikai Onkológia, 4(2), (2017-06-28)
Stereotactic radiotherapy
Particle therapy
Abscopal effect
Immunotherapy
Checkpoint inhibitors
Sugárkezelés és immunterápia kombinációja
info:eu-repo/semantics/article
oai:zenodo.org:7868559
2023-06-06T02:27:26Z
user-laserlab
openaire_data
user-aco-astro-chemical-origins
user-eu
Vincent Richardson
Daniel B. Rap
Sandra Brünken
Daniela Ascenzi
2023-04-29
<p>The series of folder contain the .log files from Gaussian(R) 16 of the different species and at different level of theories, as specified in the subfolders and filenames. The data refer to calculations that have been submitted for publication as an original research paper:</p>
<p>Title: "Infrared action spectroscopy as tool for probing gas-phase dynamics: Protonated Dimethyl Ether, (CH<sub>3</sub>)<sub>2</sub>OH<sup>+</sup>, formed by the reaction of CH<sub>3</sub>OH<sub>2</sub><sup>+</sup> with CH<sub>3</sub>OH</p>
<p>Journal: Molecular Physics</p>
<p>Authors: V. Richardson, D.B. Rap, S. Brünken and D. Ascenzi</p>
The research leading to these results has received funding from LASERLAB-EUROPE (grant agreement no. 871124, European Union's Horizon 2020 research and innovation programme), from the Deutsche Forschungsgemeinschaft (DFG, grant SCHL 341/15–1), and from NWO Exact and Natural Sciences through the use of supercomputer facilities at SURFsara in Amsterdam (NWO Rekentijd grant 2021.055). This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska Curie grant agreement No 811312
for the project "Astro-Chemical Origins" (ACO) and from MUR PRIN 2020 project n. 2020AFB3FX "Astrochemistry beyond the second period elements".
https://doi.org/10.5281/zenodo.7868559
oai:zenodo.org:7868559
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https://doi.org/10.5281/zenodo.7868558
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Infrared action spectroscopy as tool for probing gas-phase dynamics: Protonated Dimethyl Ether ((CH3)2OH+) formed by the reaction of CH3OH2+ with CH3OH
info:eu-repo/semantics/other
oai:zenodo.org:7817622
2023-04-11T14:33:38Z
user-laserlab
user-eu
Wang, H.
Zhang, W.
Ladika, D.
Yu, H.
Gailevičius, D.
Wang, H.
Pan, C.-F.
Nair, P. N. S.
Ke, Y.
Mori, T.
Chan, J. Y. E.
Ruan, Q.
Farsari, M.
Malinauskas, M.
Juodkazis, S.
Gu, M.
Yang, J. K. W.
2023-03-22
<p>The rapid development of additive manufacturing has fueled a revolution in various research fields and industrial applications. Among the myriad of advanced 3D printing techniques, two-photon polymerization lithography (TPL) uniquely offers a significant advantage in nanoscale print resolution, and has been widely employed in diverse fields, for example, life sciences, materials sciences, mechanics, and microfluidics. More recently, by virtue of the optical transparency of most of the resins used, TPL is finding new applications in optics and photonics, with nanometer to millimeter feature dimensions. It enables the minimization of optical elements and systems, and exploration of light-matter interactions with new degrees of freedom, never possible before. To review the recent progress in the TPL related optical research, it starts with the fundamentals of TPL and material formulation, then discusses novel fabrication methods, and a wide range of optical applications. These applications notably include diffractive, topological, quantum, and color optics. With a panoramic view of the development, it is concluded with insights and perspectives of the future development of TPL and related potential optical applications.</p>
https://doi.org/10.1002/adfm.202214211
oai:zenodo.org:7817622
eng
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Adv. Funct. Mater., 2023, 2214211, (2023-03-22)
3D printing
additive manufacturing
two-photon polymerization lithography
direct laser writing
light-matter interaction
optics
photonics
Two-Photon Polymerization Lithography for Optics and Photonics: Fundamentals, Materials, Technologies, and Applications
info:eu-repo/semantics/article
oai:zenodo.org:3519028
2021-07-19T01:48:16Z
user-laserlab
user-eu
Sawicka-Chyla, Magdalena
Divoky, Martin
Slezak, Ondrej
De Vido, Mariastefania
Lucianetti, Antonio
Mocek, Tomas
2019-07-19
<p>A thermo-optical design study of different slab geometries for a concept of a cryogenically cooled multislab amplifier operating at 10 J/ 100 Hz is presented. A finite element method (FEM) is used for 3-D analysis of heat distribution, temperature, stress, and strain. From this data, birefringence, depolarization losses, and wavefront distortion are calculated for a single pass through the amplifier consisting of four slabs. A comparison of different slab shapes shows that a squareshape geometry produces the smallest thermal gradients at the outer sides of the beam region, which results in smaller depolarization losses. Although the design with square-shape slabs is more sensitive to misalignment, our study shows better results compared to the case of circular-shape slabs.</p>
https://doi.org/10.1109/JQE.2019.2929962
oai:zenodo.org:3519028
eng
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IEEE JOURNAL OF QUANTUM ELECTRONICS, 55(5), 5100108, (2019-07-19)
High power lasers
thermooptical effects
multislab laser architecture
Numerical Analysis of Thermal Effects in a Concept of a Cryogenically Cooled Yb: YAG Multislab 10 J/100-Hz Laser Amplifier
info:eu-repo/semantics/article
oai:zenodo.org:7313723
2022-11-25T10:06:41Z
user-laserlab
user-eu
Calvagna, Chiara
Lapini, Andrea
Taschin, Andrea
Fanetti, Samuele
Pagliai, Marco
Bartolini, Paolo
Bini, Roberto
Righini, Roberto
Torre, Renato
2021-09-01
<p>The presence of ions induces perturbations in the water network, these structural and dynamic modifications can extent over space scales overcoming the local solvation shell: aqueous solutions of sodium perchlorate (NaClO4) are characterized by extended phenomena of structure breaking of the solvent network. The aim of the present work is the experimental investigation of the interplay between the local structural modifications induced by the perchlorate ions and the collective dynamical properties of the solvent. Ultrafast Optical Kerr Effect (OKE) and time resolved infrared absorption are the experimental techniques adopted: OKE is mostly sensitive to the collective properties of the sample, while transient IR provides access to local properties of the solvent. Classical Molecular Dynamics (MD) simulations support the analysis of the experimental results. All experiments and simulations are performed at room temperature, varying the concentrations (0-6 M) and varying the applied pressure (10-4 – 1.3 GPa). Experiments and computer simulations confirm that pressure and concentration have convergent effects on the water dynamics, due to the analogous modification of the short-range liquid structure that cancel some dynamical anomalies typical of pure water. Both local and collective dynamic observables point to structural properties as responsible for their peculiar pressure and concentration dependence.</p>
https://doi.org/10.1016/j.molliq.2021.116273
oai:zenodo.org:7313723
eng
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Journal of Molecular Liquids, 337, 116273, (2021-09-01)
Water
Water dynamics
Ultrafast spectroscopy
High pressure
Optical Kerr effect
Water solutions
Modification of local and collective dynamics of water in perchlorate solution, induced by pressure and concentration
info:eu-repo/semantics/article
oai:zenodo.org:5704860
2021-11-16T13:48:47Z
user-laserlab
user-eu
Tserevelakis, George J.
Mavrakis, Kostas G.
Pantazopoulou, Danai
Lagoudaki, Eleni
Detorakis, Efstathios
Zacharakis, Giannis
2020-10-12
<p>We demonstrate the development and application of a prototype hybrid microscopy system integrating autofluorescence (AF) and photoacoustic (PA) label-free contrast modes, for the differentiation of ocular tumors in human surgical biopsies. Hybrid imaging was performed in conjunctival nevi and uveal melanomas tissue sections to acquire quantified data for each molecular background. The AF and PA signals were spatially correlated to establish a novel malignancy indicator that could detect melanomas with high accuracy (t-test; 𝑝<0.01). The proposed methodology has the potential to simplify relevant diagnostic procedures and paves the way for the development of novel ophthalmoscopes aiming to the early diagnosis of ocular malignancies in a clinical setting.</p>
https://doi.org/10.1364/OL.403435
oai:zenodo.org:5704860
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Optics Letters, 45(20), 5748-5751, (2020-10-12)
Microscopy
Optics & Photonics
Absorption coefficient
Bandpass filters
Diode pumped lasers
Nd:YAG lasers
Optical imaging
Spatial resolution
Hybrid autofluorescence and photoacoustic label-free microscopy for the investigation and identification of malignancies in ocular biopsies
info:eu-repo/semantics/article
oai:zenodo.org:7360591
2022-11-28T12:01:13Z
user-laserlab
user-eu
Papucci, Costanza
Charaf, Rima
Coppola, Carmen
Sinicropi, Adalgisa
Di Donato, Mariangela
Taddei, Maria
Foggi, Paolo
Battisti, Antonella
de Jong, Bastiaan
Zani, Lorenzo
Mordini, Alessandro
Pucci, Andrea
Calamante, Massimo
Reginato, Gianna
2021-10-11
<p>Luminescent solar concentrators (LSCs) are devices designed to efficiently collect both direct and diffuse solar radiation and concentrate it on photovoltaic cells to foster their use in building-integrated photovoltaics (BIPV). The optimization of LSC performances involves the adjustment of both the fluorophore and the guest polymer matrix. On this account, we investigated a series of high quantum yield, donor–acceptor–donor (D–A–D) photostable fluorophores (DQ1–5), presenting a central quinoxalinic acceptor core, not previously employed in LSCs, and triarylamines or phenothiazine as donor groups. The molecules were also decorated with alkyl chains on the central core and/or the donor groups, to explore their compatibility with the poly(methyl methacrylate) (PMMA) and poly(cyclohexyl methacrylate) (PCMA) matrices utilized in this study. The PMMA and PCMA films (25 μm thick), containing 0.2–2.2 wt% of DQ1–5, absorbed in the 370–550 nm range and presented emission maxima at 550–600 nm, with fluorescence quantum yields higher than 40% even at the highest doping contents. Notably, the DQ1/PMMA thin-films showed enhanced phase compatibility and excellent quantum yields, <em>i.e.</em>, >95%. Accordingly, they were designed to obtain 25 cm<sup>2</sup> area LSCs with remarkable internal (<em>η</em><sub>int</sub>) and external (<em>η</em><sub>ext</sub>) photon efficiencies of 42.9% and 6.2%, respectively, higher than those observed from state-of-the-art devices based on the Lumogen Red 305 (LR305) as the reference fluorophore. Overall, these were the best results ever achieved in our laboratory for thin-film LSCs built with organic fluorescent emitters.</p>
https://doi.org/10.1039/d1tc02923a
oai:zenodo.org:7360591
eng
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J. Mater. Chem. C, 9(43), 15608-15621, (2021-10-11)
Transient absorption spectroscopy
Fluorescence lifetime imaging
Luminescent solar concentrators
Luminescent Solar Concentrators with Outstanding Optical Properties by Employment of D-A-D Quinoxaline Fluorophores
info:eu-repo/semantics/article
oai:zenodo.org:826078
2020-01-20T15:08:17Z
user-laserlab
user-eu
Furch, Federico J.
Witting, Tobias
Giree, Achut
Luan, Chao
Schell, Felix
Arisholm, Gunnar
Schulz, Claus P.
Vrakking, Marc J. J.
2017-06-22
<p>Noncollinear optical parametric amplifiers (NOPAs) have become the leading technique for the amplification of carrier-envelope phase (CEP)-stable, few-cycle pulses at high repetition rate and high average power. In this Letter, a NOPA operating at a repetition rate of 100 kHz delivering more than 24 W of average power before compression is reported. The amplified bandwidth supports sub-7 fs pulse durations and pulse compression close to the transform limit is realized. CEP stability after amplification is demonstrated. The system paves the way to attosecond pump-probe spectroscopy with electron–ion coincidence detection.</p>
https://doi.org/10.1364/OL.42.002495
oai:zenodo.org:826078
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Optics Letters, 42(13), 2495-2498, (2017-06-22)
Ultrafast optics
Ultrafast nonlinear optics
Parametric oscillators and amplifiers
Ultrafast technology
CEP-stable few-cycle pulses with more than 190 μJ of energy at 100 kHz from a noncollinear optical parametric amplifier
info:eu-repo/semantics/article
oai:zenodo.org:7313719
2022-11-11T14:26:25Z
user-laserlab
user-eu
Boschetti, A.
Pattelli, L.
Torre, R.
Wiersma, D.S.
2022-06-23
<p>Spectroscopic applications are characterized by the constant effort to combine high spectral resolution with large bandwidth. A tradeoff typically exists between these two aspects, but the recent development of super-resolved spectroscopy techniques is bringing new opportunities into this field. This is particularly relevant for all applications where compact and cost-effective instruments are needed, such as in sensing, quality control, environmental monitoring or biometric authentication, to name a few. These unconventional approaches exploit several strategies for spectral investigation, taking advantage of concepts such as sparse sampling, artificial intelligence or post-processing reconstruction algorithms. In this perspective paper, we discuss the main strengths and weaknesses of these methods, tracing promising future directions for their further development and widespread adoption.</p>
https://doi.org/10.1063/5.0096519
oai:zenodo.org:7313719
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Applied Physics Letters, 120, 250502, (2022-06-23)
Reconstructive spectroscopy
Speckled pattern-based spectroscopy
Super-resolved spectroscopy
Stochastic optical reconstruction spectroscopy
Perspectives and recent advances in super-resolution spectroscopy: Stochastic and disordered-based approaches
info:eu-repo/semantics/article
oai:zenodo.org:7313795
2022-11-28T08:17:26Z
user-laserlab
user-eu
Doria, Sandra
Taddei, Maria
Cupellini, Lorenzo
Biagiotti, Giacomo
Bartolini, Paolo
Bussotti, Laura
Cicchi, Stefano
Foggi, Paolo
Mennucci, Benedetta
Di Donato, Mariangela
2022-04-01
<p>Although the photophysics of BODIPY compounds has been widely investigated in the last few years, their analogue N-BODIPY compounds, with nitrogen substitution at the Boron center, did not receive comparable attention. In this work we report about the systhesis and photochemical characterization of a substituted N-BODIPY compound, by means of a combined theoretical and spectroscopic approach. Compared to a standard BODIPY, the compound under investigation presents a lower fluorescence quantum yield (QY) in the visible region. The excited state relaxation dynamics of the dye was studied in different solvents, showing further fluorescence quenching in polar solvents, and a excited state decay rates strongly dependent on the environment polarity. The role of the pendant moieties and the involvement of charge transfer states in the excited state dynamics was experimentally addressed by transient absorption spectroscopy, and further analyzed with TD-DFT calculations, which allowed precise assignment of the transient signals to the correspondent electronic configuration. The complete picture of the N-BODIPY behavior shows the presence of both charge transfer and localized states, influencing the observed photophysics to different amounts, depending on the<br>
excitation conditions and the surrounding environment.</p>
https://doi.org/10.1016/j.dyepig.2022.110181
oai:zenodo.org:7313795
eng
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Dyes and Pigments, 200, 110181, (2022-04-01)
N-BODIPY
Transient Absorption Spectroscopy
Charge transfer states
DFT computations
Unravelling the ultrafast dynamics of a N-BODIPY compound
info:eu-repo/semantics/article
oai:zenodo.org:157334
2020-01-20T15:26:09Z
user-laserlab
user-eu
Furch, Federico J.
Giree, Achut
Morales, Felipe
Anderson, Alexandria
Wang, Yicheng
Schulz, Claus Peter
Vrakking, Marc J. J.
2016-08-11
<p>Non-collinear optical parametric amplification has become the leading technology for amplifying few-cycle carrier-envelope phase (CEP) stable pulses to high energy at extreme repetition rates. In this work, a parametric amplifier system devoted to ultrafast photoionization experiments with coincidence detection is reported. The amplifier delivers CEP-stable few-cycle pulses with an average power of 5 W, and operates at repetition rates between 400 and 800 kHz. Close to transform-limited compression of the few-cycle pulses is achieved with minimized spatio-temporal distortions. Potential limitations introduced by spatio-temporal couplings to applications in attosecond science are analyzed. In particular, it is shown that pulse front tilt resulting from non-collinear amplification can considerably reduce the asymmetry in stereo above threshold ionization (stereo-ATI) experiments.</p>
https://doi.org/10.1364/OE.24.019293
oai:zenodo.org:157334
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Optics Express, 24(17), 19293-19310, (2016-08-11)
Ultrafast nonlinear optics
Nonlinear optics, parametric processes
Strong field laser physics
Close to transform-limited, few-cycle 12 µJ pulses at 400 kHz for applications in ultrafast spectroscopy
info:eu-repo/semantics/article
oai:zenodo.org:7313821
2022-11-25T14:26:27Z
user-laserlab
user-eu
Imran, Muhammad
Taddei, Maria
Sukhanov, Andrey A.
Bussotti, Laura
Ni, Wenjun
Foggi, Paolo
Gurzadyan, Gagik G.
Zhao, Jianzhang
Di Donato, Mariangela
Voronkova, Violeta K.
2022-02-22
<p>Attaching stable radicals to organic chromophores is an effective method to enhance the intersystem crossing (ISC) of the chromophores. Herein we prepared perylene-oxoverdazyl dyads either by directly connecting the two units or using an intervening phenyl spacer. We investigated the effect of the radical on the photophysical properties of perylene and observed strong fluorescence quenching due to radical enhanced ISC (REISC). Compared with a previously reported perylene-fused nitroxide radical compound (triplet lifetime, τ<sub>T</sub>=0.1 μs), these new adducts show a longer-lived triplet excited state (τ<sub>T</sub>=9.5 μs). Based on the singlet oxygen quantum yield (Φ<sub>Δ</sub>=7 %) and study of the triplet state, we propose that the radical enhanced internal conversion also plays a role in the relaxation of the excited state. Femtosecond fluorescence up-conversion indicates a fast decay of the excited state (<1.0 ps), suggesting a strong spin-spin exchange interaction between the two units. Femtosecond transient absorption (fs-TA) spectra confirmed direct triplet state population (within 0.5 ps). Interestingly, by fs-TA spectra, we observed the interconversion of the two states (D<sub>1</sub>↔Q<sub>1</sub>) at ∼80 ps time scale. Time-resolved electron paramagnetic resonance (TREPR) spectral study confirmed the formation of the quartet sate. We observed triplet and quartet states simultaneously with weights of 0.7 and 0.3, respectively. This is attributed to two different conformations of the molecule at excited state. DFT computations showed that the interaction between the radical and the chromophore is ferromagnetic (<em>J</em>>0, 0.05∼0.10 eV).</p>
https://doi.org/10.1002/cphc.202100912
oai:zenodo.org:7313821
eng
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ChemPhysChem, 23(8), e202100912, (2022-02-22)
electron spin polarization
perylene
radical-enhanced intersystem crossing
spin-spin exchange
triplet state
Radical-Enhanced Intersystem Crossing in Perylene-Oxoverdazyl Radical Dyads
info:eu-repo/semantics/article
oai:zenodo.org:840089
2020-01-20T17:40:52Z
user-laserlab
user-eu
Metzkes, J.
Zeil, K.
Kraft, S. D.
Karsch, L.
Sobiella, M.
Rehwald, M.
Obst, L.
Schlenvoigt, H.-P.
Schramm, U.
2016-08-01
<p>In this paper, a scintillator-based online beam profile detector for the characterization of laser-driven proton beams is presented. Using a pixelated matrix with varying absorber thicknesses, the proton beam is spatially resolved in two dimensions and simultaneously energy-resolved. A thin plastic scintillator placed behind the absorber and read out by a CCD camera is used as the active detector material. The spatial detector resolution reaches down to ∼4 mm and the detector can resolve proton beam profiles for up to 9 proton threshold energies. With these detector design parameters, the spatial characteristics of the proton distribution and its cut-off energy can be analyzed online and on-shot under vacuum conditions. The paper discusses the detector design, its characterization and calibration at a conventional proton source, as well as the first detector application at a laser-driven proton source.</p>
https://doi.org/10.1063/1.4961576
oai:zenodo.org:840089
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Review of Scientific Instruments, 87, 083310, (2016-08-01)
Protons
Scintillation detectors
Cameras
Laser sensors
Particle beam detectors
An online, energy-resolving beam profile detector for laser-driven proton beams
info:eu-repo/semantics/article
oai:zenodo.org:4002045
2020-08-27T00:59:23Z
user-laserlab
user-eu
Marmatakis, Konstantinos
Pergantis, Spiros A.
Anglos, Demetrios
2016-10-28
<p>A novel methodology is proposed that combines sonic spray ionization (SSI) mass spectrometry (MS) with laser induced breakdown spectroscopy (LIBS) for analyzing metal-containing biomolecules and complexes. Focusing pulses from a nanosecond laser (Nd:YAG, λ=1064 nm) in the microdroplet ensemble produced by a pneumatic nebulizer yielded LIBS spectra that enabled highly sensitive detection of several metal ions in aqueous and aqueous methanolic solutions. Based on the calibration curve method, LOD values at the ng/mL level were achieved for Ca (15 ng/mL), Ba (27 ng/mL), Cu (67 ng/mL) and Fe (650 ng/mL) with accuracy N90%. LIBS measurements were performed for the first time on aerosols of solutions of known biomolecules such as superoxide dismutase and alpha-lactalbumin, which led to the reliable determination of the concentration of Cu and Ca, respectively, both in the range of a few μg/mL. In parallel, the relative molecular mass of the metalloproteins was determined by separate SSI-MS measurements performed using an identical pneumatic nebulizer based sample introduction system. This is a first step towards the ultimate aim of integrating the two analytical techniques by use of a single pneumatic nebulization system for simultaneous sample introduction for both LIBS and SSI-MS. Such a system is expected to greatly enhance our capabilities to simultaneously acquire molecular and atomic data.</p>
https://doi.org/10.1016/j.sab.2016.10.020
oai:zenodo.org:4002045
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Spectrochimica Acta Part B, 126, 103-109, (2016-10-28)
Laser-induced breakdown spectroscopy
Sonic spray ionization mass spectrometry
Aerosols
Metalloproteins
Elemental and molecular analysis of metal containing biomolecules using laser induced breakdown spectroscopy and sonic spray ionization mass spectrometry: A step towards full integration and simultaneous analysis
info:eu-repo/semantics/article
oai:zenodo.org:10101884
2023-11-13T10:54:35Z
user-laserlab
user-eu
Duda, Martin
von Grafenstein, Lorenz
Bock, Martin
Ueberschaer, Dennis
Fürtjes, Pia
Roškot, Lukáš
Smrž, Martin
Novák, Ondřej
Griebner, Uwe
2022-05-31
<p>We report on high-energy, few-cycle pulse generation in the long-wave infrared spectral region via difference-frequency generation (DFG) in GaSe and AgGaSe2nonlinear crystals. The DFG is driven by the signal at 3.5 μm and idler at 5 μm of a high-power mid-wave infrared optical parametric chirped pulse amplification (OPCPA) system operating at a 1-kHz repetition rate. The DFG pulses contain up to 17 μJ of energy and cover a spectrum from 8.5 μm to 14.5 μm. They are generated with a conversion efficiency of 2.1 %. Compression results in 10.2-μJ pulses with sub-150-fs duration, corresponding to less than four optical cycles.</p>
https://doi.org/10.1364/OL.456971
oai:zenodo.org:10101884
eng
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Opt. Lett., 47, 2891-2894, (2022-05-31)
OPCPA
pulse generation
dfg
difference-frequency generation
10 μJ few-cycle 12μm source based on difference-frequency generation driven by a 1 kHz mid-wave infrared OPCPA
info:eu-repo/semantics/article
oai:zenodo.org:7313751
2022-11-25T10:09:09Z
user-laserlab
user-eu
Dong, Yu
Taddei, Maria
Doria, Sandra
Bussotti, Laura
Zhao, Jianzhang
Mazzone, Gloria
Di Donato, Mariangela
2021-04-30
<p>We prepared a series of <em>meso</em>-thienyl boron-dipyrromethene (Bodipy) derivatives to investigate the spin–orbit charge transfer intersystem crossing (SOCT-ISC). The photophysical properties of the compounds were studied by steady-state and femtosecond/nanosecond transient absorption spectroscopy, as well as density functional theory (DFT) computations. Different from the <em>meso</em>-phenyl Bodipy analogues, the <em>meso</em>-thienyl Bodipy are weakly fluorescent. Based on femtosecond transient absorption and DFT computations, we propose that the torsion of the thienyl group and the distortion of the Bodipy core (19.7 ps) in the S<sub>1</sub> state lead to a conical intersection on the potential energy surface as an efficient nonradiative decay channel (408 ps), which is responsible for the observed weak fluorescence as compared to the <em>meso</em>-phenyl analogue. The increased fluorescence quantum yield (from 5.5 to 14.5%) in viscous solvents supports this hypothesis. With the electron donor 4′-hydroxylphenyl moiety attached to the <em>meso</em>-thienyl unit, the fast charge separation (CS, 15.3 ps) and charge recombination (CR, 238 ps) processes outcompete the torsion-induced nonradiative decay and induce fast ISC through the SOCT-ISC mechanism. The triplet quantum yield of the electron donor/acceptor dyad is highly dependent on solvent polarity (Φ<sub>T</sub> = 1.9–45%), which supports the SOCT-ISC mechanism, and the triplet-state lifetime is up to 247.3 μs. Using the electron donor–acceptor dyad showing SOCT-ISC as a triplet photosensitizer, efficient triplet–triplet annihilation (TTA) upconversion was observed with a quantum yield of up to 6.0%.</p>
https://doi.org/10.1021/acs.jpcb.1c00053
oai:zenodo.org:7313751
eng
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J. Phys. Chem. B, 125(18), 4779–4793, (2021-04-30)
Electrical properties
Excited states
Fluorescence
Quantum yield
Solvents
Torsion-Induced Non-Radiative Relaxation of the Singlet Excited State of meso- Thienyl Bodipy, and the Charge Separation, Charge Recombination-Induced Intersystem Crossing in Its Compact Electron Donor/Acceptor Dyads
info:eu-repo/semantics/article
oai:zenodo.org:7313810
2022-11-25T14:26:27Z
user-laserlab
user-eu
Doria, Sandra
Di Donato, Mariangela
Borrelli, Raffaele
Gelin, Maxim F.
Caram, Justin
Pagliai, Marco
Foggi, Paolo
Lapini, Andrea
2022-03-31
<p>Self assembled ordered structures, such as H- or J- type molecular aggregates of organic chromophores, are extremely interesting materials for different optoelectronic applications. In this work we present a novel characterization of light harvesting nanotubes formed by self-assembling of amphiphilic cyanine dyes in water, through a combined ultrafast spectroscopic and theoretical approach. In the condition of low inhomogeneous disorder at low temperature, broadband transient absorption spectroscopy revealed the presence of an unusual ultrafast behavior of the aggregate, manifested through intense and peculiar oscillations of the kinetic traces, lasting tens of picoseconds. Theoretical simulations were performed by adapting a model which grasps vibronically coherent effects in the double wall nanotube system experiencing inter-wall energy transfer. Good agreement between model predictions and experimental observations were obtained under the assumption of coupling between bright and dark electronic states. The model clarified the vibronic origin of the observed oscillations, evidencing new important pieces of information about transport mechanisms and excitonic interactions in these complex molecular systems.</p>
https://doi.org/10.1039/d2tc00203e
oai:zenodo.org:7313810
eng
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Journal of Materials Chemistry C, 10, 7126-7226, (2022-03-31)
Linear spectroscopy
Temperature dependent transient absorption spectroscopy
2D electronic spectroscopy
Vibronic coherences in light harvesting nanotubes: unravelling the role of dark states
info:eu-repo/semantics/article
oai:zenodo.org:4001979
2020-08-27T00:59:23Z
user-laserlab
Palikaras, Konstantinos
Mari, Meropi
Petanidou, Barbara
Pasparaki, Angela
Filippidis, George
Tavernarakis, Nektarios
2016-11-24
<p>Age-dependent collapse of lipid homeostasis results in spillover of lipids and excessive fat deposition in nonadipose tissues. Ectopic fat contributes to lipotoxicity and has been implicated in the development of a metabolic syndrome that increases risk of age-associated diseases. However, the molecular mechanisms coupling ectopic fat accumulation with aging remain obscure. Here, we use nonlinear imaging modalities to visualize and quantify agedependent ectopic lipid accumulation in Caenorhabditis elegans. We find that aging is accompanied by pronounced deposition of lipids in nonadipose tissues, including the nervous system. Importantly, interventions that promote longevity such as low insulin signaling, germ-line loss, and dietary restriction, which effectively delay aging in evolutionary divergent organisms, diminish the rate of ectopic fat accumulation and the size of lipid droplets. Suppression of lipotoxic accumulation of fat in heterologous tissues is dependent on helix-loop-helix (HLH)-30/transcription factor EB (TFEB) and autophagy. Our findings in their totality highlight the pivotal role of HLH-30/TFEB and autophagic processes in the maintenance of lipid homeostasis during aging, in addition to establishing nonlinear imaging as a powerful tool for monitoring ectopic lipid droplet deposition in vivo.</p>
https://doi.org/10.1194/jlr.M069385
oai:zenodo.org:4001979
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Journal of Lipid Research, 58, 72-80, (2016-11-24)
aging
imaging
lipotoxicity
nonlinear phenomena
third harmonic generation
second harmonic generation
Ectopic fat deposition contributes to age-associated pathology in Caenorhabditis elegans
info:eu-repo/semantics/article
oai:zenodo.org:292629
2020-01-20T16:36:57Z
user-laserlab
user-eu
Giree, Achut
Mero, Mark
Arisholm, Gunnar
Vrakking, Marc J. J.
Furch, Federico J.
2017-02-06
<p>During amplification in a noncollinear optical parametric amplifier the spatial and temporal coordinates of the amplified field are inherently coupled. These couplings or distortions can limit the peak intensity, among other things. In this work, a numerical study of the spatiotemporal distortions in BBO-based noncollinear optical parametric chirped-pulse amplifiers (NOPCPAs) is presented for a wide range of parameters and for different amplification conditions. It is shown that for Gaussian pump beams, gain saturation introduces strong distortions and high conversion efficiency always comes at the price of strong spatiotemporal couplings which drastically reduce the peak intensity even when pulse fronts of the pump and the signal are matched. However, high conversion efficiencies with minimum spatiotemporal distortions can still be achieved with flat-top pump beam profiles.</p>
https://doi.org/10.1364/OE.25.003104
oai:zenodo.org:292629
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Optics Express, 25(4), 3104-3121, (2017-02-06)
Phase matching
Pulse compression
Second harmonic generation
Spatial frequency
Strong field physics
Ultrafast optics
Numerical study of spatiotemporal distortions in noncollinear optical parametric chirped-pulse amplifiers
info:eu-repo/semantics/article
oai:zenodo.org:7360759
2022-11-28T12:04:28Z
user-laserlab
openaire_data
user-eu
Medved', Miroslav
Hoorens, Mark W. H.
Di Donato, Mariangela
Laurent, Adèle D.
Fan, Jiayun
Taddei, Maria
Hilbers, Michiel
Feringa, Ben L.
Buma, Wybren Jan
Szymanski, Wiktor
2021-02-09
<p>Multi-responsive functional molecules are key for obtaining user-defined control of the properties and functions of chemical and biological systems. In this respect, pH-responsive photochromes, whose switching can be directed with light and acid–base equilibria, have emerged as highly attractive molecular units. The challenge in their design comes from the need to accommodate application-defined boundary conditions for both light- and protonation-responsivity. Here we combine time-resolved spectroscopic studies, on time scales ranging from femtoseconds to seconds, with density functional theory (DFT) calculations to elucidate and apply the acidochromism of a recently designed iminothioindoxyl (ITI) photoswitch. We show that protonation of the thermally stable <em>Z</em> isomer leads to a strong batochromically-shifted absorption band, allowing for fast isomerization to the metastable <em>E</em> isomer with light in the 500–600 nm region. Theoretical studies of the reaction mechanism reveal the crucial role of the acid–base equilibrium which controls the populations of the protonated and neutral forms of the <em>E</em> isomer. Since the former is thermally stable, while the latter re-isomerizes on a millisecond time scale, we are able to modulate the half-life of ITIs over three orders of magnitude by shifting this equilibrium. Finally, stable bidirectional switching of protonated ITI with green and red light is demonstrated with a half-life in the range of tens of seconds. Altogether, we designed a new type of multi-responsive molecular switch in which protonation red-shifts the activation wavelength by over 100 nm and enables efficient tuning of the half-life in the millisecond–second range.</p>
<p> </p>
<p>Article information: <a href="https://doi.org/10.1039/D0SC07000A">https://doi.org/10.1039/D0SC07000A</a></p>
https://doi.org/10.5281/zenodo.7360759
oai:zenodo.org:7360759
eng
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https://doi.org/10.5281/zenodo.7360758
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Chem. Sci, 12, 4588-4598, (2021-02-09)
photochromes
time-resolved spectroscopy
Tailoring the optical and dynamic properties of iminothioindoxyl photoswitches through acidochromism
info:eu-repo/semantics/other
oai:zenodo.org:265353
2020-01-20T13:09:33Z
user-laserlab
user-eu
Wachulak, Przemyslaw
Torrisi, Alfio
Bartnik, Andrzej
Węgrzyński, Łukasz
Fok, Tomasz
Fiedorowicz, Henryk
2016-12-24
<p>A compact, desktop size microscope, based on laser-plasma source and equipped with reflective condenser and diffractive Fresnel zone plate objective, operating in the extreme ultraviolet (EUV) region at the wavelength of 13.8 nm, was developed. The microscope is capable of capturing magnified images of objects with 95-nm full-pitch spatial resolution (48 nm 25–75% KE) and exposure time as low as a few seconds, combining reasonable acquisition conditions with stand-alone desktop footprint. Such EUV microscope can be regarded as a complementary imaging tool to already existing, well-established ones. Details about the microscope, characterization, resolution estimation and real sample images are presented and discussed.</p>
https://doi.org/10.1007/s00340-016-6595-5
oai:zenodo.org:265353
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Applied Physics B, 123, 25, (2016-12-24)
A desktop extreme ultraviolet microscope based on a compact laser‑plasma light source
info:eu-repo/semantics/article
oai:zenodo.org:10148923
2023-11-17T11:34:01Z
user-laserlab
Marcek Chorvatova, Alzbeta
Teplicky, Tibor
Valica, Martin
Mateasik, Anton
Chorvat, Dusan
2020-02-21
<p>Nanoparticles (NPs) from various metals (Zinc, Nickel, Cobalt, Copper) were designed and fabricated by direct synthesis using femtosecond laser ablation in liquids. Employing confocal microscopy with spectral detection and fluorescence lifetime imaging (FLIM), we have evaluated interaction of fabricated NPs with living Chlorella sp. algae by means of their naturally presented endogenous fluorescence. Live cell imaging was done in spectral region 500-550 nm and 650-710 nm to evaluate the effect of NPs on both, the green and the red fluorescence that is derived from flavonoids/carotenoids and chlorophylls respectively. We observed fluorescence intensity decrease in the red spectral region by all but Ni NPs. The presence of NPs also lead to an increase in the blue fluorescence at 477-488 nm, possibly resulting from reflected light. Gathered observations constitute the first step towards creation of methodological approaches for fast natural biosensing of the effects of environmental pollution directly in live algae.</p>
https://doi.org/10.1117/12.2543332
oai:zenodo.org:10148923
eng
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Proc. SPIE 11254, Nanoscale Imaging, Sensing, and Actuation for Biomedical Applications XVII, 1125402, (2020-02-21)
SPIE BiOS 2020, San Francisco, California, United States
Nanoparticles
femtosecond laser ablation
endogenous fluorescence
algae
Biosensing the presence of nanoparticles using endogenous fluorescence in live algae
info:eu-repo/semantics/article
oai:zenodo.org:888776
2020-01-20T14:24:39Z
user-laserlab
user-eu
Hideghéty, Katalin
Szabó, Rita Emilia
Polanek, Róbert
Szabó, Zoltán
Brunner, Szilvia
Tőkés, Tünde
2017-05-16
<p>The planned laser-driven ionizing beams (photon, very high energy electron, proton, carbon ion) at laser facilities have the unique property of ultra-high dose rate (>Gy/s^-10), short pulses, and at ELI-ALPS high repetition rate, carry the potential to develop novel laser-driven methods towards compact hospital-based clinical application. The enhanced flexibility in particle and energy selection, the high spatial and time resolution and extreme dose rate could be highly beneficial in radiotherapy. These approaches may increase significantly the therapeutic index over the currently available advanced radiation oncology methods. We highlight two nuclear reaction-based binary modalities and the planned radiobiology research.<br>
Boron Neutron Capture Therapy is an advanced cell targeted modality requiring 10B enriched boron carrier and appropriate neutron beam. The development of laser-based thermal and epithermal neutron source with as high as 10^10 fluence rate could enhance the research activity in this promising field.<br>
Boron-Proton Fusion reaction is as well as a binary approach, where 11B containing compounds are accumulated into the cells, and the tumour selectively irradiated with protons. Due to additional high linear energy transfer alpha particle release of the BPFR and the maximum point of the Bragg-peak is increased, which result in significant biological effect enhancement. Research at ELI-ALPS on detection of biological effect differences of modified or different quality radiation will be presented using recently developed zebrafish embryo and rodent models.</p>
https://doi.org/10.1117/12.2268300
oai:zenodo.org:888776
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Proc. SPIE 10239, Medical Applications of Laser-Generated Beams of Particles IV: Review of Progress and Strategies for the Future, 10239, 102390A, (2017-05-16)
laser-driven Boron Neutron capture
Boron-Proton Fusion
zebrafish embryo model
New approaches in clinical application of laser-driven ionizing radiation
info:eu-repo/semantics/article
oai:zenodo.org:5710207
2021-11-18T13:48:49Z
user-laserlab
user-eu
Tsafas, Vassilis
Gavgiotaki, Evangelia
Tzardi, Maria
Tsafa, Effrosyni
Fotakis, Costas
Athanassakis, Irene
Filippidis, George
2020-07-09
<p>Nonlinear optical imaging techniques have been widely used to reveal biological structures for accurate diagnosis at the cellular as well as the tissue level. In the present study, polarization-dependent second-harmonic generation (PSHG) was used to determine collagen orientation in breast cancer biopsy tissues (grades 0, I, II and III). The obtained data were processed using fast Fourier transform (FFT) analysis, while second-harmonic generation (SHG) anisotropy and the “ratio parameter” values were also calculated. Such measurements were shown to be able to distinguish collagen structure modifications in different cancer grades tested. The analysis presented herein suggests that PSHG imaging could provide a quantitative evaluation of the tumor state and the distinction of malignant from benign breast tissues. The obtained results also allowed the development of a biophysical model, which can explain the aforementioned differentiations and is in agreement with the simulations relating the SHG anisotropy values with the mechanical tension applied to the collagen during cancer progression. The current approach could be a step forward for the development of new, nondestructive, label free optical diagnostic tools for cancer reducing the need of recalls and unnecessary biopsies, while potentially improving cancer detection rates.</p>
https://doi.org/10.1002/jbio.202000180
oai:zenodo.org:5710207
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Journal of Biophotonics, 13(10), e202000180, (2020-07-09)
breast cancer
collagen
diagnosis
nonlinear optical microscopy
polarization-dependent measurements
second harmonic generation imaging
Polarization-dependent second-harmonic generation for collagen-based differentiation of breast cancer samples
info:eu-repo/semantics/article
oai:zenodo.org:888874
2020-01-20T16:43:54Z
user-laserlab
user-eu
Horný, Vojtěch
Nejdl, Jaroslav
Kozlová, Michaela
Krůs, Miroslav
Boháček, Karel
Petržílka, Václav
Klimo, Ondřej
2017-06-01
<p>The temporal profile of X-ray betatron radiation was theoretically studied for the parameters available with current laser systems. Characteristics of the betatron radiation were investigated for three different configurations of laser wakefield acceleration: typical self-injection regime and optical injection regime with perpendicularly crossed injection and drive beams, both achievable with 100 TW class laser, and ionization injection regime with a sub-10 TW laser system that was experimentally verified. Constructed spectrograms demonstrate that X-ray pulse durations are in the order of few tens of femtoseconds and the optical injection case reveals the possibility of generating X-ray pulses as short as 2.6 fs. The X-ray pulse duration depends mainly on the length of the trapped electron bunch as the emitted photons copropagate with the bunch with nearly the same velocity. These spectrograms were calculated using a novel simplified method based on the theory of Liénard-Wiechert potentials. It takes advantage of the fact that the electron oscillates transversally in the accelerating plasma wave in the wiggler regime and, thus, emits radiation almost exclusively in the turning points of its sine-like trajectory. Therefore, there are only few very narrow time intervals, which contribute significantly to the emission of radiation, while the rest can be neglected. These narrow time intervals are determined from the electron trajectories calculated using particle-in-cell simulations and the power spectrum at given point in far field is computed for each electron using the Fourier transform. Spectrograms of the emitted radiation are constructed by summing contributions of individual particles, since the incoherent nature of the electron bunch is assumed.</p>
https://doi.org/10.1063/1.4985687
oai:zenodo.org:888874
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Physics of Plasmas, 24, 063107, (2017-06-01)
Betatrons
X-rays
Wigglers
X-ray lasers
Particle-in-cell method
Temporal profile of betatron radiation from laser-driven electron accelerators
info:eu-repo/semantics/article
oai:zenodo.org:7360815
2022-11-25T14:26:31Z
user-laserlab
user-eu
Estrela, Patrícia
Maçôas, Ermelinda
Williams, Gareth
Hussain, Mukhtar
Fajardo, Marta
2021-07-01
<p>As high harmonic generation (HHG) sources have proliferated, the need for high resolution, affordable extreme ultraviolet (XUV) detectors has become ubiquitous. We studied lithium fluoride (LiF) crystals, traditionally used for x rays, as a detector for a tabletop XUV source from high harmonic generation in gases. The LiF response curve showed a dynamic range of 103 (not saturated), with a minimum threshold fluence of 66µJ/cm2. Imaging tests were performed revealing sub-micrometer spatial resolution. We successfully recorded a scan of the focal plane of a Fresnel zone plate with high dynamic range. With this study, we showed that LiF can be used as a detector for HHG XUV, with a high potential to do near field imaging of complex objects such as the focus of structured light.</p>
https://doi.org/10.1364/JOSAB.422767
oai:zenodo.org:7360815
eng
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Journal of the Optical Society of America B, 38(7), 2234-2238, (2021-07-01)
lithium fluoride crystals
x ray imaging
near field imaging
Lithium fluoride detectors for high spatial resolution imaging of tabletop XUV from high harmonic generation in gases
info:eu-repo/semantics/article
oai:zenodo.org:892073
2020-01-20T15:54:52Z
user-laserlab
user-eu
Veyrinas, K.
Gruson, V.
Weber, S. J.
Barreau, L.
Ruchon, T.
Hergott, J.-F.
Houver, J.C.
Lucchese, R. R.
Salières, P.
Dowek, D.
2016-11-17
<p>Due to the intimate anisotropic interaction between an XUV light field and a molecule resulting in photoionization (PI), molecular frame photoelectron angular distributions (MFPADs) are most sensitive probes of both electronic/nuclear dynamics and the polarization state of the ionizing light field. Consequently, they encode the complex dipole matrix elements describing the dynamics of the PI transition, as well as the three normalized Stokes parameters <em>s</em><sub>1</sub>, <em>s</em><sub>2</sub>, <em>s</em><sub>3</sub> characterizing the complete polarization state of the light, operating as molecular polarimetry. The remarkable development of advanced light sources delivering attosecond XUV pulses opens the perspective to visualize the primary steps of photochemical dynamics in time-resolved studies, at the natural attosecond to few femtosecond time-scales of electron dynamics and fast nuclear motion. It is thus timely to investigate the feasibility of measurement of MFPADs when PI is induced <em>e.g.</em>, by an attosecond pulse train (APT) corresponding to a comb of discrete high-order harmonics. In the work presented here, we report MFPAD studies based on coincident electron-ion 3D momentum imaging in the context of ultrafast molecular dynamics investigated at the PLFA facility (CEA-SLIC), with two perspectives: (i) using APTs generated in atoms/molecules as a source for MFPAD-resolved PI studies, and (ii) taking advantage of molecular polarimetry to perform a complete polarization analysis of the harmonic emission of molecules, a major challenge of high harmonic spectroscopy. Recent results illustrating both aspects are reported for APTs generated in unaligned SF<sub>6</sub> molecules by an elliptically polarized infrared driving field. The observed fingerprints of the elliptically polarized harmonics include the first direct determination of the complete <em>s</em><sub>1</sub>, <em>s</em><sub>2</sub>, <em>s</em><sub>3</sub> Stokes vector, equivalent to (<em>ψ</em>, <em>ε</em>, <em>P</em>), the orientation and the signed ellipticity of the polarization ellipse, and the degree of polarization <em>P</em>. They are compared to so far incomplete results of XUV optical polarimetry. We finally discuss the comparison between the outcomes of photoionization and high harmonic spectroscopy for the description of molecular photodynamics.</p>
https://doi.org/10.1039/C6FD00137H
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Faraday Discussions, 194, 161-183, (2016-11-17)
Photoionization
Ultrafast imaging of photochemical dynamics
Molecular frame photoemission by a comb of elliptical high-order harmonics: a sensitive probe of both photodynamics and harmonic complete polarization state
info:eu-repo/semantics/article
oai:zenodo.org:10148907
2023-11-17T11:33:02Z
user-laserlab
Marcek Chorvatova, Alzbeta
Uherek, Martin
Mateasik, Anton
Bondarev, Dimitrij
Freek, Ariese
Chorvat, Dusan
2023-03-16
<p>Environmental pollution by microplastics (MPs) represents a serious burden of the 21st century. Sensing the interactions of photosynthetic organisms with MPs is based on the study of their endogenous fluorescence derived from chlorophylls. Fluorescently labelled custom-made MPs were tested. We also recorded endogenous fluorescence of the moss in the presence of "naturally-occurring" MPs (polyethylene content of 2 mg/g, non fluorescent) in suspended matter (SM) from the river Rhine. Performed experiments evaluated the distribution of the MPs, as well as the sensitivity of endogenous fluorescence of chlorophylls to their presence. Understanding the interaction of living organisms with MPs will help to assess the impact of this environmental pollution and eventually to propose new approaches for its removal from water sources.</p>
https://doi.org/10.1117/12.2644814
oai:zenodo.org:10148907
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Proc. SPIE 12394, Nanoscale Imaging, Sensing, and Actuation for Biomedical Applications XX, 1239407, (2023-03-16)
SPIE BiOS 2023, San Francisco, California, United States
microplastics
chlorophylls
Fontinalis antipyretica moss
confocal microscopy
spectroscopy
FLIM
biosensing
Sensing the interaction of living organisms with microplastics by microscopy methods
info:eu-repo/semantics/article
oai:zenodo.org:215414
2020-01-20T15:47:13Z
user-laserlab
user-eu
Martelli, Fabrizio
Binzoni, Tiziano
Pifferi, Antonio
Spinelli, Lorenzo
Farina, Andrea
Torricelli, Alessandro
2016-06-03
<p>We propose a comprehensive statistical approach describing the penetration depth of light in random media. The presented theory exploits the concept of probability density function <em>f</em>(<em>z</em>|<em>ρ</em>, <em>t</em>) for the maximum depth reached by the photons that are eventually re-emitted from the surface of the medium at distance <em>ρ</em> and time <em>t</em>. Analytical formulas for <em>f</em>, for the mean maximum depth 〈<em>z</em><sub><em>max</em></sub>〉 and for the mean average depth reached by the detected photons at the surface of a diffusive slab are derived within the framework of the diffusion approximation to the radiative transfer equation, both in the time domain and the continuous wave domain. Validation of the theory by means of comparisons with Monte Carlo simulations is also presented. The results are of interest for many research fields such as biomedical optics, advanced microscopy and disordered photonics.</p>
https://doi.org/10.1038/srep27057
oai:zenodo.org:215414
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Scientific Reports, 6, 27057, (2016-06-03)
Fluorescence spectroscopy
Near-infrared spectroscopy
Raman spectroscopy
There's plenty of light at the bottom: statistics of photon penetration depth in random media
info:eu-repo/semantics/article
oai:zenodo.org:840170
2020-01-20T14:43:04Z
user-laserlab
user-eu
Kokurewicz, K.
Welsh, G. H.
Brunetti, E.
Wiggins, S. M.
Boyd, M.
Sorensen, A.
Chalmers, A.
Schettino, G.
Subiel, A.
DesRosiers, C.
Jaroszynski, D. A.
2017-05-16
<p>As an alternative modality to conventional radiotherapy, electrons with energies above 50 MeV penetrate deeply into tissue, where the dose can be absorbed within a tumour volume with a relatively small penumbra. We investigate the physical properties of VHEEs and review the state-of-the-art in treatment planning and dosimetry. We discuss the advantages of using a laser wakefield accelerator (LWFA) and present the characteristic features of the electron bunch produced by the LWFA and compare them with that from a conventional linear accelerator.</p>
https://doi.org/10.1117/12.2271183
oai:zenodo.org:840170
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Proc. SPIE 10239, Medical Applications of Laser-Generated Beams of Particles IV: Review of Progress and Strategies for the Future, 10239, 102390C, (2017-05-16)
Electrons
Lasers
Plasmas
Radiotherapy
Tissues
Radiation dosimetry
Linear particle accelerators
Laser-plasma generated very high energy electrons (VHEEs) in radiotherapy
info:eu-repo/semantics/conferencePaper
oai:zenodo.org:5643436
2021-11-04T01:48:32Z
user-laserlab
user-eu
Csanaková, Bianka
Novák, Ondřej
Smrž, Martin
Huynh, Jaroslav
Jelínková, Helena
Lucianetti, Antonio
Mocek, Tomáš
2021-01-04
<p>The availability of optical elements for the mid-infrared wavelength range, such as polarizers and wavelength separators, is limited especially when a broadband wavelength range coverage is required. We propose a polarizer based on uncoated silicon Brewster plates. A detailed analysis of the polarizer’s contrast and the influence of parasitic reflections, its dependence on wavelength, and the angular misalignment is shown. Two different arrangements of the two- and four-plate polarizers are discussed. With contrast including the influence of parasitic reflections of over 103 for the whole transparency range of silicon (1.2–6.5 µm), the four-plate polarizer is an effective, low-cost, high-power compatible tool providing sufficient contrast for signal and idler beam separation of the broadband mid-infrared Type II optical parametric sources. The proposed polarizers can function as an attenuator assembly without any wave plate.</p>
https://doi.org/10.1364/AO.411408
oai:zenodo.org:5643436
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Other (Non-Commercial)
Lasers
Optical Amplifiers
Laser Optics
Silicon Brewster plate wavelength separator for a mid-IR optical parametric source
info:eu-repo/semantics/article
oai:zenodo.org:7305167
2022-11-09T16:13:37Z
user-laserlab
user-eu
Zielbauer, Bernhard
2022-11-09
<p>A design for an ion spectrometer was developed in the frame of the Laserlab Europe V Joint Research Activity "PRISES". This zip file contains the construction drawings for the self-developed components and a document which describes the design considerations.</p>
https://doi.org/10.5281/zenodo.7305167
oai:zenodo.org:7305167
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https://doi.org/10.5281/zenodo.7305166
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laser particle physics
plasma diagnostics
ion spectrometer
Design for a Thomson parabola ion spectrometer
info:eu-repo/semantics/other
oai:zenodo.org:10149027
2023-11-17T11:55:27Z
user-laserlab
user-eu
Marcek Chorvatova, Alzbeta
Uherek, Martin
Chorvat, Dusan
2020-07-10
https://doi.org/10.1007/s00249-021-01558-w
oai:zenodo.org:10149027
eng
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Eur Biophys J 50 (Suppl 1), (2020-07-10)
13th European Biophysics Conference, Vienna, Austria, 24-28 July 2021
microscopy
pollution
FLIM
nanoparticles
femtosecond laser ablation
Evaluation of the effect of environmental pollution on water moss by time- and spectrally-resolved microscopy
info:eu-repo/semantics/other
oai:zenodo.org:5708439
2021-11-18T01:48:50Z
user-laserlab
user-eu
Marcek Chorvatova, Alzbeta
Cagalinec, Michal
Chorvat, Dusan
2021-06-13
<p>Time-resolved fluorescence spectrometry is a highly valuable technological tool to detect and characterize mitochondrial metabolic oxidative changes by means of endogenous fluorescence. Here, we describe detection and measurement of endogenous mitochondrial flavin fluorescence directly in living cardiac cells using fluorescence lifetime imaging microscopy (FLIM) after excitation with 473 nm picoseconds (ps) laser. Time-correlated single photon counting (TCSPC) method is employed.</p>
https://doi.org/10.1007/978-1-0716-1262-0_26
oai:zenodo.org:5708439
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Mitochondrial oxidative state
Endogenous flavin fluorescence
FLIM
TCSPC
Energy metabolism
Time-Resolved Imaging of Mitochondrial Flavin Fluorescence and Its Applications for Evaluating the Oxidative State in Living Cardiac Cells
info:eu-repo/semantics/article
oai:zenodo.org:1162144
2020-01-20T17:11:00Z
user-laserlab
user-eu
Grafenstein, Lorenz von
Bock, Martin
Ueberschaer, Dennis
Zawilski, Kevin
Schunemann, Peter
Griebner, Uwe
Elsaesser, Thomas
2017-09-21
<p>A mid-infrared (mid-IR) optical parametric chirped pulse amplification (OPCPA) system generating few-cycle pulses with multi-gigawatt peak power at a 1 kHz repetition rate is reported. The system is pumped by a highly stable 2 μm picosecond chirped pulse amplifier based on Ho:YLF gain media to exploit the high nonlinearity of ZnGeP<sub>2</sub> (ZGP) crystals for parametric amplification. The ZGP optical parametric amplification (OPA) is characterized by a high conversion efficiency of >10 %, resulting in 1.3 mJ idler pulses at a center wavelength of 5.1 μm. Employing a dispersion management scheme based only on bulk materials, pulses as short as 160 fs are obtained. By adding a spatial light modulator in the OPCPA setup, the pulses are further recompressed to 75 fs duration which corresponds to less than five optical cycles. Taking into account the pulse energy of 0.65 mJ in this configuration, it translates into a peak power of 7.7 GW. The achieved pulse durations and peak powers, to the best of our knowledge, represent record values for high-energy mid-IR OPCPAs beyond 4 μm.</p>
https://doi.org/10.1364/OL.42.003796
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Optics Letters, 42(19), 3796-3799, (2017-09-21)
Infrared and far-infrared lasers
Ultrafast lasers
Parametric oscillators and amplifiers
5 μm few-cycle pulses with multi-gigawatt peak power at a 1 kHz repetition rate
info:eu-repo/semantics/article
oai:zenodo.org:264017
2020-01-20T15:15:43Z
user-laserlab
user-eu
Torrisi, Alfio
Wachulak, Przemyslaw
Węgrzyński, Łukasz
Fok, Tomasz
Bartnik, Andrzej
Parkman, Tomáš
Vondrová, Šárka
Turňová, Jana
Jankiewicz, Bartłomiej J.
Bartosewicz, Bartosz
Fiedorowicz, Henryk
2016-10-21
<p>We report on a very compact desk-top transmission extreme ultraviolet (EUV) microscope based on a laser-plasma source with a double stream gas-puff target, capable of acquiring magnified images of objects with a spatial (half-pitch) resolution of sub-50 nm. A multilayer ellipsoidal condenser is used to focus and spectrally narrow the radiation from the plasma, producing a quasi-monochromatic EUV radiation (λ = 13.8 nm) illuminating the object, while a Fresnel zone plate objective forms the image. Design details, development, characterization and optimization of the EUV source and the microscope are described and discussed. Test object and other samples were imaged to demonstrate superior resolution compared to visible light microscopy.</p>
<p>Lay description</p>
<p>Developments in nanoscience demand tools capable of capturing images with a nanometer spatial resolution beyond the capability of well-known visible light microscopes.</p>
<p>Herein, we present the design details, development, characterization and optimization of a very compact desk-top transmission microscope, operating in invisible to an eye radiation from the so called extreme ultraviolet (EUV) range. The apparatus is based on a laser-plasma source coupled with a special type of objective called Fresnel zone plate. It is capable of acquiring magnified images of objects with a spatial resolution of sub-50 nm, approximately 5–10 times better than the spatial resolution of classical visible light microscopes, in a short acquisition time.</p>
<p>The main motivation for development of such compact systems operating with EUV radiations is the possibility to get information about thin samples due to the easily absorption of these radiation by solid materials with very small thicknesses, of the order of about 100 nm.</p>
<p>Additionally, the employment of such kind of microscopes might open the possibility to perform experiments without necessity to employ large ‘photon facilities’ such as synchrotrons or free electron lasers and could have a huge impact on the speed of nanotechnology development.</p>
<p>Imaging results, concerning nanostructures and biomedical samples, are presented and discussed.</p>
This is the peer reviewed version of the following article: A stand-alone compact EUV microscope based on gas-puff target source, Journal of Microscopy 265, 251-260 (2017), which has been published in final form at DOI: 10.1111/jmi.12494. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving
https://doi.org/10.1111/jmi.12494
oai:zenodo.org:264017
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Journal of Microscopy, 265(2), 251-260, (2016-10-21)
EUV microscopy
Fresnel zone plate
Gas-puff target
EUV source
Imaging
A stand-alone compact EUV microscope based on gas-puff target source
info:eu-repo/semantics/article
oai:zenodo.org:840662
2020-01-20T14:25:00Z
user-laserlab
user-eu
Archipovaite, Giedre Marija
Petit, Stéphane
Delagnes, Jean-Christophe
Cormier, Eric
2017-02-17
<p>We report on a laser source operating at 100 kHz repetition rate and delivering 8 μJ few-cycle mid-IR pulses at 3 μm. The system is based on optical parametric amplification pumped by a high repetition rate Yb-doped femtosecond fiber-chirped amplifier. This high-intensity ultrafast system is a promising tool for strong-field experiments (up to 50 GV/m and 186 T) in low ionization potential atomic and molecular systems, or solid-state physics with coincidence measurements. As a proof of principle, up to the sixth harmonic has been generated in a 1 mm zinc selenide sample.</p>
https://doi.org/10.1364/OL.42.000891
oai:zenodo.org:840662
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Optics Letters, 42(5), 891-894, (2017-02-17)
Condensed matter
Femtosecond fiber lasers
Laser energy
Laser systems
Phase matching
Strong field physics
100 kHz Yb-fiber laser pumped 3 μm optical parametric amplifier for probing solid-state systems in the strong field regime
info:eu-repo/semantics/article
oai:zenodo.org:3754105
2020-04-16T20:20:15Z
user-laserlab
user-eu
Mero, Mark
Petrov, Valentin
Heiner, Zsuzsanna
2020-03-02
<p>With diode-pumped Yb laser technology reaching maturity, average power scaling of multi-GW, few-cycle, short-wave<br>
and mid-infrared (MIR) optical parametric amplifiers (OPA’s) to the 100-W level has become a reality. Well<br>
established, commercially available oxide crystals offer a relatively straightforward solution in the 1.4-4-μm spectral<br>
range. Extension of the spectral coverage of high-power OPA’s beyond 5 μm may be enabled by novel, wide-bandgap<br>
non-oxide crystals with growth processes still under major development and optimization. Here, we present our results<br>
on the nonlinear optical properties of oxide (LiNbO3, KTiOAsO4) and non-oxide (LiGaS2, BaGa4S7) crystals and the<br>
resulting 100-kHz, ultrafast infrared OPA’s based on these materials. The reported data provide design parameters and<br>
guidelines for high-average-power MIR OPA’s pumped by Yb lasers both below and above 5 μm.</p>
https://doi.org/10.1117/12.2545961
oai:zenodo.org:3754105
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Proc. SPIE 11264, Nonlinear Frequency Generation and Conversion: Materials and Devices XIX, 112640F, (2020-03-02)
Nonlinear optical crystals
OPCPA
photorefractive damage
z-scan
nonlinear refractive index
KTiOAsO4
LiGaS2
BaGa4S7
Progress in ultrafast, mid-infrared optical parametric chirped pulse amplifiers pumped at 1 µm
info:eu-repo/semantics/article
oai:zenodo.org:212935
2020-01-20T13:42:34Z
user-laserlab
user-eu
van Stokkum, Ivo H. M.
Jumper, Chanelle C.
Snellenburg, Joris J.
Scholes, Gregory D.
van Grondelle, Rienk
Malý, Pavel
2016-11-30
<p>When exciting a complex molecular system with a short optical pulse, all chromophores present in the system can be excited. The resulting superposition of electronically and vibrationally excited states evolves in time, which is monitored with transient absorption spectroscopy. We present a methodology to resolve simultaneously the contributions of the different electronically and vibrationally excited states from the complete data. The evolution of the excited states is described with a superposition of damped oscillations. The amplitude of a damped oscillation cos(<em>ω<sub>n</sub>t</em>)exp(−<em>γ<sub>n</sub>t</em>) as a function of the detection wavelength constitutes a damped oscillation associated spectrum <em>DOAS<sub>n</sub></em>(<em>λ</em>) with an accompanying phase characteristic <em>φ<sub>n</sub></em>(<em>λ</em>). In a case study, the cryptophyte photosynthetic antenna complex PC612 which contains eight bilin chromophores was excited by a broadband optical pulse. Difference absorption spectra from 525 to 715 nm were measured until 1 ns. The population dynamics is described by four lifetimes, with interchromophore equilibration in 0.8 and 7.5 ps. We have resolved 24 DOAS with frequencies between 130 and 1649 cm<sup>−1</sup> and with damping rates between 0.9 and 12 ps<sup>−1</sup>. In addition, 11 more DOAS with faster damping rates were necessary to describe the “coherent artefact.” The DOAS contains both ground and excited state features. Their interpretation is aided by DOAS analysis of simulated transient absorption signals resulting from stimulated emission and ground state bleach.</p>
https://doi.org/10.1063/1.4966196
oai:zenodo.org:212935
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Creative Commons Attribution 4.0 International
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The Journal of Chemical Physics, 145(17), 174201, (2016-11-30)
Excited states
Selected area electron diffraction
Coherence
Absorption spectra
Estimation of damped oscillation associated spectra from ultrafast transient absorption spectra
info:eu-repo/semantics/article