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Leshchenko V, Smith B, Camacho Garibay A, Agostini P, Fang L, DiMauro LF. Nanoplasma resonance condition in the middle-infrared spectral range. Phys Rev E 2023; 107:055207. [PMID: 37328980 DOI: 10.1103/physreve.107.055207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 04/21/2023] [Indexed: 06/18/2023]
Abstract
The resonance-absorption condition in the laser-nanoplasma interactions has been considered to follow the wavelength dependence of the critical plasma density. We experimentally demonstrate that this assumption fails in the middle-infrared spectral range, while it is valid for visible and near-infrared wavelengths. A thorough analysis supported by molecular dynamic (MD) simulations indicates that the observed transition in the resonance condition is caused by the reduction of the electron scattering rate and the associated increase of the cluster outer-ionization contribution. An expression for the nanoplasma resonance density is derived based on experimental results and MD simulations. The findings are important for a broad range of plasma experiments and applications, since the extension of the laser-plasma interaction studies to longer wavelengths has become increasingly topical.
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Affiliation(s)
- V Leshchenko
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
- NeXUS facility, Institute for Optical Science, The Ohio State University, Columbus, Ohio 43210, USA
| | - B Smith
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - A Camacho Garibay
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - P Agostini
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - L Fang
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - L F DiMauro
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
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2
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Woodbury D, Goffin A, Schwartz RM, Isaacs J, Milchberg HM. Self-Guiding of Long-Wave Infrared Laser Pulses Mediated by Avalanche Ionization. PHYSICAL REVIEW LETTERS 2020; 125:133201. [PMID: 33034483 DOI: 10.1103/physrevlett.125.133201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 08/18/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
Nonlinear self-guided propagation of intense long-wave infrared (LWIR) laser pulses is of significant recent interest, as it promises high power transmission without beam breakup and multifilamentation. Central to self-guiding is the mechanism for the arrest of self-focusing collapse. Here, we show that discrete avalanche sites centered on submicron aerosols can arrest self-focusing, providing a new mechanism for self-guided propagation of moderate intensity LWIR pulses in outdoor environments. Our conclusions are supported by simulations of LWIR pulse propagation using an effective index approach that incorporates the time-resolved plasma dynamics of discrete avalanche breakdown sites.
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Affiliation(s)
- D Woodbury
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
| | - A Goffin
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
| | - R M Schwartz
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
| | - J Isaacs
- Plasma Physics Division, U.S. Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375, USA
| | - H M Milchberg
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
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3
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Sarkar S, Gopal R, Anand M, Kumar MP, Krishnamurthy M. On the importance of field driven single particle processes in short pulse absorption of clusters. Sci Rep 2019; 9:15135. [PMID: 31641204 PMCID: PMC6805859 DOI: 10.1038/s41598-019-51385-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 09/06/2019] [Indexed: 11/09/2022] Open
Abstract
Nano-clusters are acclaimed to be very efficient absorbers of intense femto second light due to dominant collective mechanisms. Enhanced near 100% absorption due to collective linear plasma resonance compared to a small fraction of absorption by unclustered gas was an important drive in nano-plasma studies. Contrary to such perception, we show that if the pulse duration is (<100 fs), absorption is same irrespective of whether the systems are condensed to large clusters or not. So long as there are same number of similar ionizable systems in the focal volume, absorption is the same and such absorption can be accounted for by single particle response to the field and collisional ionization of atoms. Short pulse absorption by the single particle response can be comparable to the linear plasma resonance absorption for smaller clusters.
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Affiliation(s)
- Soubhik Sarkar
- Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Colaba, Mumbai, 400 005, India
| | - R Gopal
- Tata Institute of Fundamental Research, Gopanpally, Hyderabad, 500 107, India
| | - M Anand
- Tata Institute of Fundamental Research, Gopanpally, Hyderabad, 500 107, India
| | - M Praveen Kumar
- Tata Institute of Fundamental Research, Gopanpally, Hyderabad, 500 107, India
| | - M Krishnamurthy
- Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Colaba, Mumbai, 400 005, India. .,Tata Institute of Fundamental Research, Gopanpally, Hyderabad, 500 107, India.
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4
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Gao X, Shim B, Downer MC. Brunel harmonics generated from ionizing clusters by few-cycle laser pulses. OPTICS LETTERS 2019; 44:779-782. [PMID: 30767985 DOI: 10.1364/ol.44.000779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 12/28/2018] [Indexed: 06/09/2023]
Abstract
We study theoretically harmonic generation from ionizing nano-clusters irradiated by intense few-cycle laser pulses and identify a Brunel-type harmonic generation mechanism that originates from subcycle ionization dynamics in clusters. Compared to Brunel harmonics in gases, the spectra are shifted toward odd-order harmonics of Mie frequency ωM due to efficient excitation of Mie oscillations. Considering the appreciable single-cluster harmonic yield and the relaxed phase-matching condition in overdense clustered plasmas, clusters driven by few-cycle laser pulses can be a promising source of vacuum-ultraviolet radiation.
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5
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Vu DT, Jang D, Kim KY. Simplified chirp characterization in single-shot supercontinuum spectral interferometry. OPTICS EXPRESS 2018; 26:20572-20581. [PMID: 30119366 DOI: 10.1364/oe.26.020572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 07/19/2018] [Indexed: 06/08/2023]
Abstract
Single-shot supercontinuum spectral interferometry (SSSI) is an optical technique that can measure ultrafast transients in the complex index of refraction. This method uses chirped supercontinuum reference/probe pulses that need to be pre-characterized prior to use. Conventionally, the spectral phase (or chirp) of those pulses can be determined from a series of phase or spectral measurements taken at various time delays with respect to a pump-induced modulation. Here we propose a novel method to simplify this process and characterize reference/probe pulses up to the third order dispersion from a minimum of 2 snapshots taken at different pump-probe delays. Alternatively, without any pre-characterization, our method can retrieve both unperturbed and perturbed reference/probe phases, including the pump-induced modulation, from 2 time-delayed snapshots. From numerical simulations, we show that our retrieval algorithm is robust and can achieve high accuracy even with 2 snapshots. Without any apparatus modification, our method can be easily applied to any experiment that uses SSSI.
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6
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Electron–Ion Impact Energy Transfer in Nanoplasmas of Coulomb Exploding Clusters. ADVANCES IN QUANTUM CHEMISTRY 2017. [DOI: 10.1016/bs.aiq.2017.01.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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7
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Bang W. Disassembly time of deuterium-cluster-fusion plasma irradiated by an intense laser pulse. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:013102. [PMID: 26274289 DOI: 10.1103/physreve.92.013102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Indexed: 06/04/2023]
Abstract
Energetic deuterium ions from large deuterium clusters (>10nm diameter) irradiated by an intense laser pulse (>10(16)W/cm(2)) produce DD fusion neutrons for a time interval determined by the geometry of the resulting fusion plasma. We present an analytical solution of this time interval, the plasma disassembly time, for deuterium plasmas that are cylindrical in shape. Assuming a symmetrically expanding deuterium plasma, we calculate the expected fusion neutron yield and compare with an independent calculation of the yield using the concept of a finite confinement time at a fixed plasma density. The calculated neutron yields agree quantitatively with the available experimental data. Our one-dimensional simulations indicate that one could expect a tenfold increase in total neutron yield by magnetically confining a 10-keV deuterium fusion plasma for 10ns.
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Affiliation(s)
- W Bang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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8
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Mohamed WT, Chen G, Kim J, Tao GX, Ahn J, Kim DE. Controlling the length of plasma waveguide up to 5 mm, produced by femtosecond laser pulses in atomic clustered gas. OPTICS EXPRESS 2011; 19:15919-15928. [PMID: 21934955 DOI: 10.1364/oe.19.015919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report the observation of longitudinally uniform plasma waveguide with a controlled length of up to nearly 5 mm, in argon clustered gas jet. This self-channeling plasma is obtained using a 35 mJ, 30 fs FWHM pulse as a pump laser pulse to create the plasma channel. A 1 mJ pulse of the same laser is used for probing the plasma channels using interferometric diagnostics. The radial distribution of the electron density confirms the formation of a plasma waveguide. Clustered argon enhances the absorption efficiency of femtosecond pulses which enables the use of pump pulses of only 35 mJ, approximately 10 times less energy than required for heating conventional gas targets. The plasma channel length is controlled by the laser focus point (F), the laser intensity (I), the pump-probe delay time (t) and the laser height from a nozzle (z). The variation of the electron density for these parameters is also studied. We found that the highest density of 1.2 x 10(19) cm(-3) was obtained at I = 5.2 x 10(16) W/cm(2), z = 2 mm and t = 7.6 ns. It was demonstrated that by using a clustered jet, both the plasma waveguide length and the plasma density could be controlled.
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Affiliation(s)
- Walid Tawfik Mohamed
- Department of Physics & Center for Attosecond Science and Technology (CASTECH), Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea
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9
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Lu H, Chen G, Ni G, Li R, Xu Z. Impact of Gas Backing Pressure and Geometry of Conical Nozzle on the Formation of Methane Clusters in Supersonic Jets. J Phys Chem A 2009; 114:2-9. [DOI: 10.1021/jp902094g] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Haiyang Lu
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China, and Key Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China
| | - Guanglong Chen
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China, and Key Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China
| | - Guoquan Ni
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China, and Key Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China
| | - Ruxin Li
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China, and Key Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China
| | - Zhizhan Xu
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China, and Key Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China
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10
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Layer BD, York AG, Varma S, Chen YH, Milchberg HM. Periodic index-modulated plasma waveguide. OPTICS EXPRESS 2009; 17:4263-4267. [PMID: 19293850 DOI: 10.1364/oe.17.004263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrate a wire-obstructed cluster flow technique for making periodically modulated plasma waveguides in hydrogen, nitrogen, and argon with sharp, stable voids as short as 50 microm with a period as small as 200 microm. These gaps persist as the plasma expands for the full lifetime of the waveguide. We demonstrate guided propagation at intensities up to 2 x 10(17) W/cm(2), limited by our laser energy currently available. This technique is useful for quasi-phase matching applications where index-modulated guides are superior to diameter modulated guides.
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Affiliation(s)
- B D Layer
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742, USA.
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11
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Layer BD, York A, Antonsen TM, Varma S, Chen YH, Leng Y, Milchberg HM. Ultrahigh-intensity optical slow-wave structure. PHYSICAL REVIEW LETTERS 2007; 99:035001. [PMID: 17678290 DOI: 10.1103/physrevlett.99.035001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Indexed: 05/16/2023]
Abstract
We report the development of corrugated "slow-wave" plasma guiding structures with application to quasiphase-matched direct laser acceleration of charged particles and generation of a wide spectrum of electromagnetic radiation. These structures support guided propagation at intensities up to 2 x 10(17) W/cm(2), limited by our current laser energy and side leakage. Hydrogen and argon plasma waveguides up to 1.5 cm in length with corrugation period as short as 35 microm are generated in a cryogenic cluster jet. Experimental data are consistent with simulations showing periodic modulations of the laser pulse intensity.
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Affiliation(s)
- B D Layer
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA
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12
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Shim B, Hays G, Zgadzaj R, Ditmire T, Downer MC. Enhanced harmonic generation from expanding clusters. PHYSICAL REVIEW LETTERS 2007; 98:123902. [PMID: 17501124 DOI: 10.1103/physrevlett.98.123902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Indexed: 05/15/2023]
Abstract
We report controlled enhancement of optical third harmonic generation (THG) from hydrodynamically expanding clusters of approximately 6x10(5) noble-gas atoms several hundred femtoseconds following ionization and heating by ultrashort pump pulses. This resonant enhancement is more pronounced for orthogonal than for parallel pump-probe polarizations, a consequence of faster cluster expansion along the pump polarization. Simulations show that the nonlinear susceptibility chi(3) of the individual clusters and the coherence length of the clustered plasma medium are optimized nearly simultaneously as the clusters expand, and both contribute to the observed THG enhancement. This dual enhancement mechanism may be scalable to relativistic probe intensity and to generation of high-order harmonics in the soft-x-ray regime.
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Affiliation(s)
- B Shim
- FOCUS Center, Department of Physics, University of Texas at Austin, Austin, Texas 78712-1081, USA
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13
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Tiggesbäumker J, Stienkemeier F. Formation and properties of metal clusters isolated in helium droplets. Phys Chem Chem Phys 2007; 9:4748-70. [PMID: 17712454 DOI: 10.1039/b703575f] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The unique conditions forming atomic and molecular complexes and clusters using superfluid helium nanodroplets have opened up an innovative route for studying the physical and chemical properties of matter on the nanoscale. This review summarizes the specific characteristics of the formation of atomic clusters partly generated far from equilibrium in the helium environment. Special emphasis is on the optical response, electronic properties as well as dynamical processes which are mostly affected by the surrounding quantum matrix. Experiments include the optical induced response of isolated cluster systems in helium under quite different excitation conditions ranging from the linear regime up to the violent interaction with a strong laser field leading to Coulomb explosion and the generation of highly charged atomic fragments. The variety of results on the outstanding properties in the quantum size regime highlights the peculiar capabilities of helium nanodroplet isolation spectroscopy.
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14
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Kim KY, Milchberg HM, Faenov AY, Magunov AI, Pikuz TA, Skobelev IY. X-ray spectroscopy of 1 cm plasma channels produced by self-guided pulse propagation in elongated cluster jets. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 73:066403. [PMID: 16906984 DOI: 10.1103/physreve.73.066403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Indexed: 05/11/2023]
Abstract
We diagnose the self-channeled propagation of intense femtosecond pulses over an extended distance in a N2O cluster gas target using high resolution kilovolt x-ray pinhole images of the channel and spatially resolved x-ray spectra. The x-ray images are consistent with femtosecond optical scattering, shadowgraphy, and interferometry images. We observe extended plasma channels (approximately 9 mm) limited either by the cluster jet length or by absorption, for injected laser intensities in the range of 10(16)-10(17) W/cm2. Spectral line shapes for the OVII 1s2-1s3p and OVIII 1s-2p transitions (at 1.8627 and 1.8969 nm, respectively) show significant broadening to the blue side and with truncated emission on the red side. We attribute this effect to Doppler blueshifted emission from fast ions from exploding clusters moving toward the spectrometer; redshifted emission from the opposite side of the cluster is absorbed.
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Affiliation(s)
- K Y Kim
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA
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15
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Peano F, Peinetti F, Mulas R, Coppa G, Silva LO. Kinetics of the collisionless expansion of spherical nanoplasmas. PHYSICAL REVIEW LETTERS 2006; 96:175002. [PMID: 16712307 DOI: 10.1103/physrevlett.96.175002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2006] [Indexed: 05/09/2023]
Abstract
The collisionless expansion of spherical plasmas composed of cold ions and hot electrons is analyzed using a novel kinetic model, with special emphasis on the influence of the electron dynamics. Simple, general laws are found, relating the relevant expansion features to the initial conditions of the plasma, determined from a single dimensionless parameter. A transition is identified in the behavior of the ion energy spectrum, which is monotonic only for high electron temperatures, otherwise exhibiting a local peak far from the cutoff energy.
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Affiliation(s)
- F Peano
- Dipartimento di Energetica, Politecnico di Torino, Italy
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16
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Milchberg HM, Kim KY, Kumarappan V, Layer BD, Sheng H. Clustered gases as a medium for efficient plasma waveguide generation. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2006; 364:647-61. [PMID: 16483955 DOI: 10.1098/rsta.2005.1729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Clustered gas jets are shown to be an efficient means for plasma waveguide generation, for both femtosecond and picosecond generation pulses. These waveguides enable significantly lower on-axis plasma density (less than 10(18) cm(-3)) than in conventional hydrodynamic plasma waveguides generated in unclustered gases. Using femtosecond pump pulses, self-guided propagation and strong absorption (more than 70%) are used to produce long centimetre scale channels in an argon cluster jet, and a subsequent intense pulse is coupled into the guide with 50% efficiency and guided at above 10(17)W cm(-2) intensity over 40 Rayleigh lengths. We also demonstrate efficient generation of waveguides using 100 ps axicon-generated Bessel-beam pump pulses. Despite the expected sub-picosecond cluster disassembly time, we observe long pulse absorption efficiencies up to a maximum of 35%. Simulations show that in the far leading edge of the long laser pulse, the volume of heated clusters evolves to a locally uniform and cool plasma already near ionization saturation, which is then efficiently heated by the remainder of the pulse.
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Affiliation(s)
- H M Milchberg
- University of Maryland Institute for Physical Science and Technology College Park, MD 20742, USA
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Sheng H, Kim KY, Kumarappan V, Layer BD, Milchberg HM. Plasma waveguides efficiently generated by Bessel beams in elongated cluster gas jets. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:036411. [PMID: 16241583 DOI: 10.1103/physreve.72.036411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2005] [Indexed: 05/05/2023]
Abstract
We demonstrate the efficient generation of plasma waveguides in elongated cluster gas jets using 100 ps axicon-generated Bessel beam pump pulses. The plasma waveguide space and time evolution is measured using picosecond interferometry. Small radius waveguides with central densities as low as approximately 10(18) cm(-3) can be generated with this technique. Despite the expected subpicosecond cluster disassembly time, we observe long pulse absorption efficiencies that can be more than a factor of 10 greater than in unclustered gas targets of the same volume average atomic density. The maximum long pulse absorption observed in cluster jets under our range of conditions was 35%. The explanation for the enhanced absorption is that in the far-leading edge of the laser pulse, the volume of heated clusters evolves to a locally uniform and cool plasma already near ionization saturation, which is then heated by the remainder of the pulse. From this perspective, the use of clustered gases is equivalent to a supercharged preionization scheme for long duration laser pulses.
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Affiliation(s)
- H Sheng
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA
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18
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Liu J, Duan Z, Zeng Z, Xie X, Deng Y, Li R, Xu Z, Chin SL. Time-resolved investigation of low-density plasma channels produced by a kilohertz femtosecond laser in air. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:026412. [PMID: 16196723 DOI: 10.1103/physreve.72.026412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2005] [Indexed: 05/04/2023]
Abstract
By employing pump-probe back longitudinal diffractometry, the electron density and decay dynamics of a weak plasma channel created by a 1-KHz fs laser in air has been investigated. With ultrashort laser pulses of 50 fs and low energy of 0.6 mJ, we observe weak plasma channels with a length approximately 2 cm in air. An analytical reconstruction method of electron density has been analyzed, which is sensitive to the phase shift and channel size. The electron density in the weak plasma channel is extracted to be about 4 x 10(16) cm(-3). The diameters of the plasma channel and the filament are about 50 and 150 microm, respectively, and the measurable electron density can be extended to less than 10(15) cm(-3). Moreover, a different time-frequency technique called linearly chirped longitudinal diffractometry is proposed to time-resolved investigate ultrafast ionization dynamics of laser-irradiated gas, laser interaction with cluster beam, etc.
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Affiliation(s)
- Jiansheng Liu
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P. O. Box 800-211, Shanghai 201800, People's Republic of China.
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19
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Dorchies F, Caillaud T, Blasco F, Bonté C, Jouin H, Micheau S, Pons B, Stevefelt J. Investigation of laser-irradiated Ar cluster dynamics from K-shell x-ray emission measurements. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:066410. [PMID: 16089883 DOI: 10.1103/physreve.71.066410] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2005] [Revised: 03/09/2005] [Indexed: 05/03/2023]
Abstract
Intense (up to a few 10(17) W/ cm2) femtosecond (down to 40 fs) laser pulses are focused onto a partially clusterized argon gas jet. The target was previously characterized and optimized in order to get a homogeneous and dense jet of clusters with a well controlled size. The interaction leads to x-ray emission that is absolutely calibrated and spectrally resolved using a high resolution time-integrated spectrometer in the K-shell range (from 2.9 to 4.3 keV). X-ray spectra are investigated as a function of different laser temporal parameters such as the nanosecond prepulse contrast, the laser pulse duration, and the femtosecond delay between two different laser pulses. The cluster size ranges from 180 to 350 angstroms and irradiation by laser pulses with both linear and circular polarization is investigated. The experimental results are discussed in terms of the laser-cluster interaction dynamics. They are compared with the predictions of collision-dominated nanoplasma models. However, further interaction processes are required in order to explain the observed characteristic lines demonstrating highly charged ions up to Ar16+.
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Affiliation(s)
- F Dorchies
- CELIA, UMR 5107, CNRS, CEA, Université Bordeaux I, 33405 Talence, France.
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Kumarappan V, Kim KY, Milchberg HM. Guiding of intense laser pulses in plasma waveguides produced from efficient, femtosecond end-pumped heating of clustered gases. PHYSICAL REVIEW LETTERS 2005; 94:205004. [PMID: 16090259 DOI: 10.1103/physrevlett.94.205004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2004] [Indexed: 05/03/2023]
Abstract
We demonstrate intense pulse guiding in efficient femtosecond end-pumped waveguides generated in clustered gases. This novel scheme provides a route to significantly lower on-axis plasma density (< 10(18) cm(-3)) more than is feasible in conventional hydrodynamic plasma waveguides. Self-focused propagation and strong absorption of intense femtosecond laser pulses are used to produce long centimeter scale channels in an argon cluster jet, and a subsequent pulse is guided with 3 x 10(17) W cm(-2) intensity and approximately 50% coupling efficiency. Preliminary results with hydrogen clusters also show guiding.
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Affiliation(s)
- V Kumarappan
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA
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21
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Luo X, Niu D, Kong X, Wen L, Liang F, Pei K, Wang B, Li H. Cluster-assistant generation of multiply charged atomic ions in nanosecond laser ionization of seeded methyl iodide beam. Chem Phys 2005. [DOI: 10.1016/j.chemphys.2004.09.033] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Peano F, Fonseca RA, Silva LO. Dynamics and control of shock shells in the coulomb explosion of very large deuterium clusters. PHYSICAL REVIEW LETTERS 2005; 94:033401. [PMID: 15698262 DOI: 10.1103/physrevlett.94.033401] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2004] [Indexed: 05/24/2023]
Abstract
The explosion dynamics of very large (approximately 10(6)-10(7) atoms) deuterium clusters irradiated by ultraintense laser pulses (I approximately 10(18) W/cm(2)) is analyzed self-consistently with one-to-one three-dimensional and two-dimensional fully relativistic particle-in-cell simulations. Small-scale shock shells in the expanding ion cloud are observed. A technique to induce the formation of large shock shells inside a single cluster, increasing the probability of intracluster nuclear reactions, is proposed and demonstrated.
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Affiliation(s)
- F Peano
- GoLP/Centro de Física dos Plasmas, Instituto Superior Técnico, 1049-001 Lisboa, Portugal
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23
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Gupta A, Antonsen TM, Milchberg HM. Propagation of intense short laser pulses in a gas of atomic clusters. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 70:046410. [PMID: 15600533 DOI: 10.1103/physreve.70.046410] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2004] [Revised: 06/16/2004] [Indexed: 05/24/2023]
Abstract
We present a model and numerical simulations for the propagation of intense short laser pulses in gases of atomic clusters. As the pulse propagates through the clusters, they absorb energy, expand and explode. The clustered gas thus acts as a medium with time dependent effective dielectric constant. A self-consistent model for the cluster expansion and the laser pulse propagation is developed. Self-focusing of the laser pulse, coupling of laser energy to clusters and the evolution of the pulse spectrum are studied for a laser-cluster system with typical laboratory parameters.
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Affiliation(s)
- Ayush Gupta
- Department of Electrical and Computer Engineering and Institute of Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
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24
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Taguchi T, Antonsen TM, Milchberg HM. Resonant heating of a cluster plasma by intense laser light. PHYSICAL REVIEW LETTERS 2004; 92:205003. [PMID: 15169361 DOI: 10.1103/physrevlett.92.205003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2003] [Revised: 01/07/2004] [Indexed: 05/24/2023]
Abstract
The heating of a single argon (Ar) cluster by a strong laser field is studied using an electrostatic particle-in-cell code for a range of intensities and cluster sizes. Heating is dominated by a nonlinear resonant absorption process involving energetic electrons transiting through the cluster. This process gives rise to a threshold in field strength for strong absorption and controls the dielectric properties of the cluster.
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Affiliation(s)
- Toshihiro Taguchi
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
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25
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Chu HH, Tsai HE, Xiao YF, Lee CH, Lin JY, Wang J, Chen SY, Chu HE. Control of laser-beam propagation and absorption in a nanoplasma gas by programming of a transient complex refractive index with a prepulse. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:035403. [PMID: 15089352 DOI: 10.1103/physreve.69.035403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2003] [Indexed: 05/24/2023]
Abstract
By utilizing the intensity- and duration-dependent heating and expansion rate of nanoplasma to generate a transient transverse gradient of the refractive index, prepulse controlled laser-beam propagation is demonstrated. The dynamical response of the macroscopic optical refractive index is traced back to the microscopic polarizability of nanoplasmas experimentally, in accordance with hydrodynamic nanoplasma models. In particular, the delay between the prepulse and the main pulse for maximum Rayleigh scattering is found to be longer than that for maximum x-ray emission, supporting the more refined one-dimensional self-consistent hydrodynamic nanoplasma model.
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Affiliation(s)
- H-H Chu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan
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Alexeev I, Antonsen TM, Kim KY, Milchberg HM. Self-focusing of intense laser pulses in a clustered gas. PHYSICAL REVIEW LETTERS 2003; 90:103402. [PMID: 12688995 DOI: 10.1103/physrevlett.90.103402] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2002] [Indexed: 05/24/2023]
Abstract
We report the self-focusing of intense laser pulses in gases composed of atomic clusters. This is in strong contrast to beam spreading owing to ionization-induced refraction commonly observed in nonclustered gases. The effect is explained in terms of the ensemble average transient polarizability of the heated clusters as they explode in response to the intense pulse.
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Affiliation(s)
- I Alexeev
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA
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