Coherent motion of particles in a plasma can imprint itself on radiation.The recent advent of high-power lasers—allowing the nonlinear inverse Compton-scattering regime to be reached—has opened the possibility of lo...Coherent motion of particles in a plasma can imprint itself on radiation.The recent advent of high-power lasers—allowing the nonlinear inverse Compton-scattering regime to be reached—has opened the possibility of looking at collective effects in laser–plasma interactions.Under certain conditions,the collective interaction of many electrons with a laser pulse can generate coherent radiation in the hard x-ray regime.This perspective paper explains the limitations under which such a regime might be attained.展开更多
We report on frequency doubling of high-energy,high repetition rate ns pulses from a cryogenically gas cooled multi-slab ytterbium-doped yttrium aluminum garnet laser system,Bivoj/DiPOLE,using a type-I phase matched l...We report on frequency doubling of high-energy,high repetition rate ns pulses from a cryogenically gas cooled multi-slab ytterbium-doped yttrium aluminum garnet laser system,Bivoj/DiPOLE,using a type-I phase matched lithium triborate crystal.We achieved conversion to 515 nm with energy of 95 J at repetition rate of 10 Hz and conversion efficiency of 79%.High conversion efficiency was achieved due to successful depolarization compensation of the fundamental input beam.展开更多
We present the workflow of the design, realization and testing of deformable mirrors suitable for high power diode pumped solid-state lasers. It starts with the study of the aberration to be corrected, and then it con...We present the workflow of the design, realization and testing of deformable mirrors suitable for high power diode pumped solid-state lasers. It starts with the study of the aberration to be corrected, and then it continues with the design of the actuators position and characteristic. In this paper, we present and compare three deformable mirrors realized for multi-J level laser facilities. We show that with the same design concept it is possible to realize deformable mirrors for other types of lasers. As an example, we report the realization of a deformable mirror for femtosecond lasers and for a CW CO_2 laser.展开更多
We present a diode-pumped, electro-optically Q-switched Tm:YAG laser with a cryogenically cooled laser crystal at120 K. Output pulses of up to 2.55 mJ and 650 ns duration were demonstrated in an actively Q-switched co...We present a diode-pumped, electro-optically Q-switched Tm:YAG laser with a cryogenically cooled laser crystal at120 K. Output pulses of up to 2.55 mJ and 650 ns duration were demonstrated in an actively Q-switched configuration with a repetition rate of 1 Hz. By using cavity dumping the pulse duration was shortened to 18 ns with only a slightly lower output energy of 2.22 mJ. Furthermore, using a simplified rate equation model, we discuss design constraints on the pump fluence in a pulse pump approach for Tm:YAG to maximize the energy storage capability at a given pump power.展开更多
The group-delay dispersion of an optical fiber was measured with the time-of-flight method, using fingerprint-like characteristic spectra from a mode-locked fiber laser source. To determine the group-delay dispersion ...The group-delay dispersion of an optical fiber was measured with the time-of-flight method, using fingerprint-like characteristic spectra from a mode-locked fiber laser source. To determine the group-delay dispersion up to the fourth order, least-squares fitting was applied to the overall time waveform mapped on the time axis for the fingerprint-spectral broadband pulses through a long optical fiber. The analysis of all 4003 data points reduced statistical uncertainty, and provided second-, third-, and fourth-order dispersion with uncertainties of 0.02%, 0.4%, and 4%,respectively.展开更多
We present experimental and numerical investigations of high-energy mid-infrared filamentation with multi-octavespanning supercontinuum generation(SCG), pumped by a 2.4 μm, 250 fs Cr:ZnSe chirped-pulse laser amplifie...We present experimental and numerical investigations of high-energy mid-infrared filamentation with multi-octavespanning supercontinuum generation(SCG), pumped by a 2.4 μm, 250 fs Cr:ZnSe chirped-pulse laser amplifier.The SCG is demonstrated in both anomalous and normal dispersion regimes with YAG and polycrystalline ZnSe,respectively. The formation of stable and robust single filaments along with the visible-to-mid-infrared SCG is obtained with a pump energy of up to 100 μJ in a 6-mm-long YAG medium. To the best of the authors’ knowledge, this is the highest-energy multi-octave-spanning SCG from a laser filament in a solid. On the other hand, the SCG and evenharmonic generation based on random quasi-phase matching(RQPM) are simultaneously observed from the single filaments in a 6-mm-long polycrystalline ZnSe medium with a pump energy of up to 15 μJ. The numerical simulations based on unidirectional pulse propagation equation and RQPM show excellent agreement with the measured multioctave-spanning SCG and even-harmonic generation. They also reveal the temporal structure of mid-infrared filaments,such as soliton-like self-compression in YAG and pulse broadening in ZnSe.展开更多
Development of high energy laser sources with nanosecond pulses at several hertz values for repetition rate has been very attractive in recent years due to their great potential for practical applications. With the re...Development of high energy laser sources with nanosecond pulses at several hertz values for repetition rate has been very attractive in recent years due to their great potential for practical applications. With the recent advancement in fabricating large size laser quality transparent ceramics, diode pumped solid-state laser generating pulse energy of 100 J at 10 Hz has been recently realized at HiLASE center using Yb:YAG ceramic with Cr:YAG cladding. This review discusses Yb based high energy lasers, specific laser geometries for efficient thermal management and the role of transparent ceramics in such diode pumped high-energy-class solid-state lasers around the world.展开更多
Controlling the spatial distribution of functional groups on two-dimensional(2D)materials on a micrometer scale and below represents a fascinating opportunity to achieve anisotropic(opto)electronic properties of these...Controlling the spatial distribution of functional groups on two-dimensional(2D)materials on a micrometer scale and below represents a fascinating opportunity to achieve anisotropic(opto)electronic properties of these materials.Periodic patterns of covalent functionalization can lead to pericxJic potentials in the monolayer;however,creating such superstructures is very challenging.Here,we describe an original approach to the periodic functionalization of graphene induced by substrate patterning using a pulsed laser.Laser-induced periodic surface structures(LIPSS)are produced on silicon wafers with thermally-grown oxide layers.The irradiation conditions for the formation of UPSS confined at the SiO2/Si interface have been unravelled.LIPSS imprint their periodicity to the reactivity of the monolayer graphene placed on the substrate via modulation of its local doping level.This method is clean,straightforward and scalable with high spatial resolution.展开更多
When Fojtik and Henglein [1] submitted in 1992 the first scientific paper on generation of nanoparticles(NPs) by laser ablation in liquids, the authors probably could not realize how it will revolutionize the nanopart...When Fojtik and Henglein [1] submitted in 1992 the first scientific paper on generation of nanoparticles(NPs) by laser ablation in liquids, the authors probably could not realize how it will revolutionize the nanoparticle science and technology. In 2017, marking a quarter century of this pioneering study, Amendola and Barcikowski [2] pointed out that the simple and bright idea of Henglein and Fojtik was an inspiration to hundreds of scientists worldwide over 25 years and opened a way to use lasers in synthesis of colloids.展开更多
基金supported by the Czech Academy of Sciences(Mobility Plus Project No.CNRS-23-12)A.M.F.was supported by the Russian Science Foundation(Grant No.20-12-00077).
文摘Coherent motion of particles in a plasma can imprint itself on radiation.The recent advent of high-power lasers—allowing the nonlinear inverse Compton-scattering regime to be reached—has opened the possibility of looking at collective effects in laser–plasma interactions.Under certain conditions,the collective interaction of many electrons with a laser pulse can generate coherent radiation in the hard x-ray regime.This perspective paper explains the limitations under which such a regime might be attained.
基金This work was supported by the European Regional Development Fund and the state budget of the Czech Republic project HiLASE CoE(CZ.02.1.01/0.0/0.0/15_006/0000674)the Horizon 2020 Framework Programme(H2020)(739573).
文摘We report on frequency doubling of high-energy,high repetition rate ns pulses from a cryogenically gas cooled multi-slab ytterbium-doped yttrium aluminum garnet laser system,Bivoj/DiPOLE,using a type-I phase matched lithium triborate crystal.We achieved conversion to 515 nm with energy of 95 J at repetition rate of 10 Hz and conversion efficiency of 79%.High conversion efficiency was achieved due to successful depolarization compensation of the fundamental input beam.
基金co-financed by the European Regional Development Fundthe European Social Fund+1 种基金the state budget of the Czech Republic(project HiLASE:CZ.1.05/2.1.00/01.0027,project DPSSLasers:CZ.1.07/2.3.00/20.0143)partially supported by the grant RVO 68407700
文摘We present the workflow of the design, realization and testing of deformable mirrors suitable for high power diode pumped solid-state lasers. It starts with the study of the aberration to be corrected, and then it continues with the design of the actuators position and characteristic. In this paper, we present and compare three deformable mirrors realized for multi-J level laser facilities. We show that with the same design concept it is possible to realize deformable mirrors for other types of lasers. As an example, we report the realization of a deformable mirror for femtosecond lasers and for a CW CO_2 laser.
基金funding from the European Union’s Horizon 2020 research and innovation programme(871124 Laserlab-Europe and 739573)the Thuringian Ministry for Economic Affairs,Science and Digital Society(2016FE9058)+2 种基金Bundesministerium für Bildung und Forschung(BMBF)(03ZIK445,05P15SJFA1,03Z1H531,03VNE2068D)the European Regional Development Fund and the state budget of the Czech Republic(project Hi LASE CZ.02.1.01/0.0/0.0/15006/0000674)the Ministry of Education,Youth and Sports of the Czech Republic(NPU I Project No.LO1602)。
文摘We present a diode-pumped, electro-optically Q-switched Tm:YAG laser with a cryogenically cooled laser crystal at120 K. Output pulses of up to 2.55 mJ and 650 ns duration were demonstrated in an actively Q-switched configuration with a repetition rate of 1 Hz. By using cavity dumping the pulse duration was shortened to 18 ns with only a slightly lower output energy of 2.22 mJ. Furthermore, using a simplified rate equation model, we discuss design constraints on the pump fluence in a pulse pump approach for Tm:YAG to maximize the energy storage capability at a given pump power.
基金partly supported by KAKENHI No. 15H03968 and No. 26610081 from JSPS, the Photon Frontier Network Program of MEXT, JST-SENTAN, and JST-CREST in Japanthe European Regional Development Fund+1 种基金the European Social Fundthe state budget of the Czech Republic (project HiLASE: CZ.1.05/2.1.00/01.0027, project Postdok: CZ.1.07/2.3.00/30.0057)
文摘The group-delay dispersion of an optical fiber was measured with the time-of-flight method, using fingerprint-like characteristic spectra from a mode-locked fiber laser source. To determine the group-delay dispersion up to the fourth order, least-squares fitting was applied to the overall time waveform mapped on the time axis for the fingerprint-spectral broadband pulses through a long optical fiber. The analysis of all 4003 data points reduced statistical uncertainty, and provided second-, third-, and fourth-order dispersion with uncertainties of 0.02%, 0.4%, and 4%,respectively.
基金supported by the US DOE accelerator stewardship program(grant number DE-SC0018378)US DOD Office of Navy Research(ONR)DURIP(grant number N00014-17-1-2744)+5 种基金National Science Foundation(NSF)(grant number PHY-1707237)Air Force Office of Scientific Research(AFOSR)(grant number FA9550-18-1-0223)Integrated Electronics Engineering Center(IEEC)of Binghamton UniversityERDF and the state budget(grant number CZ.02.1.01/0.0/0.0/15006/0000674)MEYS(grant number LO1602,LM2015086)of the Czech RepublicEU Horizon 2020(grant number 739573)。
文摘We present experimental and numerical investigations of high-energy mid-infrared filamentation with multi-octavespanning supercontinuum generation(SCG), pumped by a 2.4 μm, 250 fs Cr:ZnSe chirped-pulse laser amplifier.The SCG is demonstrated in both anomalous and normal dispersion regimes with YAG and polycrystalline ZnSe,respectively. The formation of stable and robust single filaments along with the visible-to-mid-infrared SCG is obtained with a pump energy of up to 100 μJ in a 6-mm-long YAG medium. To the best of the authors’ knowledge, this is the highest-energy multi-octave-spanning SCG from a laser filament in a solid. On the other hand, the SCG and evenharmonic generation based on random quasi-phase matching(RQPM) are simultaneously observed from the single filaments in a 6-mm-long polycrystalline ZnSe medium with a pump energy of up to 15 μJ. The numerical simulations based on unidirectional pulse propagation equation and RQPM show excellent agreement with the measured multioctave-spanning SCG and even-harmonic generation. They also reveal the temporal structure of mid-infrared filaments,such as soliton-like self-compression in YAG and pulse broadening in ZnSe.
基金co-financed by the European Regional Development Fundthe state budget of the Czech Republic (project HiLASE CoE: Grant No. CZ.02.1.01/0.0/ 0.0/15 006/0000674)+1 种基金the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 739573the Ministry of Education, Youth and Sports of the Czech Republic (Programmes NPU I Project No. LO1602, and Large Research Infrastructure Project No. LM2015086)
文摘Development of high energy laser sources with nanosecond pulses at several hertz values for repetition rate has been very attractive in recent years due to their great potential for practical applications. With the recent advancement in fabricating large size laser quality transparent ceramics, diode pumped solid-state laser generating pulse energy of 100 J at 10 Hz has been recently realized at HiLASE center using Yb:YAG ceramic with Cr:YAG cladding. This review discusses Yb based high energy lasers, specific laser geometries for efficient thermal management and the role of transparent ceramics in such diode pumped high-energy-class solid-state lasers around the world.
基金The work was supported by project No.18-09055Y and 20-08633X awarded by Czech Science FoundationThe research of I.M.,J.S.,T.J.-Y.D.,and N.M.B.is financed by the European Regional Development Fund and the state budget of the Czech Republic(project BIATRI,No.CZ.02.1.01/0.0/0.0/15_003/0000445,project HiLASE CoE,No.CZ.02.1.01/0.0/0.0/15_006/0000674,programme NPU I,project No.LO1602)+3 种基金The work was further supported by European Regional Development Fund,OP RDE,Project:“Carbon allotropes with rationalized nanointerfaces and nanolinks for environmental and biomedical applications”(No.CZ.02.1.01/0.0/0.0/16_026/0008382)The authors also acknowledge the assistance provided by the Research Infrastructures NanoEnviCz(No.LM2015073)supported by the Ministry of EducationYouth and Sports of the Czech Republic and the project Pro-NanoEnviCz(No.CZ.02.1.01/0.0/0.0/16_013/0001821)supported by the Ministry of EducationYouth and Sports of the Czech Republic and the European Union-European Structural and Investments Funds in the frame of Operational Programme Research Development and Education.
文摘Controlling the spatial distribution of functional groups on two-dimensional(2D)materials on a micrometer scale and below represents a fascinating opportunity to achieve anisotropic(opto)electronic properties of these materials.Periodic patterns of covalent functionalization can lead to pericxJic potentials in the monolayer;however,creating such superstructures is very challenging.Here,we describe an original approach to the periodic functionalization of graphene induced by substrate patterning using a pulsed laser.Laser-induced periodic surface structures(LIPSS)are produced on silicon wafers with thermally-grown oxide layers.The irradiation conditions for the formation of UPSS confined at the SiO2/Si interface have been unravelled.LIPSS imprint their periodicity to the reactivity of the monolayer graphene placed on the substrate via modulation of its local doping level.This method is clean,straightforward and scalable with high spatial resolution.
文摘When Fojtik and Henglein [1] submitted in 1992 the first scientific paper on generation of nanoparticles(NPs) by laser ablation in liquids, the authors probably could not realize how it will revolutionize the nanoparticle science and technology. In 2017, marking a quarter century of this pioneering study, Amendola and Barcikowski [2] pointed out that the simple and bright idea of Henglein and Fojtik was an inspiration to hundreds of scientists worldwide over 25 years and opened a way to use lasers in synthesis of colloids.
