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Liekhus-Schmaltz CE, Tenney I, Osipov T, Sanchez-Gonzalez A, Berrah N, Boll R, Bomme C, Bostedt C, Bozek JD, Carron S, Coffee R, Devin J, Erk B, Ferguson KR, Field RW, Foucar L, Frasinski LJ, Glownia JM, Gühr M, Kamalov A, Krzywinski J, Li H, Marangos JP, Martinez TJ, McFarland BK, Miyabe S, Murphy B, Natan A, Rolles D, Rudenko A, Siano M, Simpson ER, Spector L, Swiggers M, Walke D, Wang S, Weber T, Bucksbaum PH, Petrovic VS. Ultrafast isomerization initiated by X-ray core ionization. Nat Commun 2015; 6:8199. [DOI: 10.1038/ncomms9199] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 07/28/2015] [Indexed: 11/09/2022] Open
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27
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Li H, Chen LJ, Cheng HPH, May JE, Smith S, Muehlig K, Uttamadoss A, Frisch JC, Fry AR, Kärtner FX, Bucksbaum PH. Remote two-color optical-to-optical synchronization between two passively mode-locked lasers. OPTICS LETTERS 2014; 39:5325-5328. [PMID: 26466262 DOI: 10.1364/ol.39.005325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Using balanced detection in both the radio frequency (RF) and the optical domain, we remotely synchronize the repetition rate of a Ti:sapphire oscillator to an Er-doped fiber oscillator through a 360 m length-stabilized dispersion compensated fiber link. The drift between these two optical oscillators is 3.3 fs root mean square (rms) over 24 hours. The 68 MHz Er-doped fiber oscillator is locked to a 476 MHz local RF reference clock, and serves as a master clock to distribute 10 fs-level timing signals through stabilized fiber links. This steady remote two-color optical-to-optical synchronization is an important step toward an integrated femtosecond fiber timing distribution system for free-electron lasers (FELs); it does not require x-ray pulses, and it makes sub-10-fs optical/x-ray pump-probe experiments feasible.
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McFarland BK, Berrah N, Bostedt C, Bozek J, Bucksbaum PH, Castagna JC, Coffee RN, Cryan JP, Fang L, Farrell JP, Feifel R, Gaffney KJ, Glownia JM, Martinez TJ, Miyabe S, Mucke M, Murphy B, Natan A, Osipov T, Petrovic VS, Schorb S, Schultz T, Spector LS, Swiggers M, Tarantelli F, Tenney I, Wang S, White JL, White W, Gühr M. Experimental strategies for optical pump – soft x-ray probe experiments at the LCLS. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/1742-6596/488/1/012015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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29
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Spector LS, Artamonov M, Miyabe S, Martinez T, Seideman T, Guehr M, Bucksbaum PH. Axis-dependence of molecular high harmonic emission in three dimensions. Nat Commun 2014; 5:3190. [DOI: 10.1038/ncomms4190] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 01/02/2014] [Indexed: 12/20/2022] Open
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30
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31
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Petrovic VS, Schorb S, Kim J, White J, Cryan JP, Glownia JM, Zipp L, Broege D, Miyabe S, Tao H, Martinez T, Bucksbaum PH. Enhancement of strong-field multiple ionization in the vicinity of the conical intersection in 1,3-cyclohexadiene ring opening. J Chem Phys 2013; 139:184309. [DOI: 10.1063/1.4829766] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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32
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Fang L, Osipov T, Murphy B, Tarantelli F, Kukk E, Cryan JP, Glownia M, Bucksbaum PH, Coffee RN, Chen M, Buth C, Berrah N. Multiphoton ionization as a clock to reveal molecular dynamics with intense short x-ray free electron laser pulses. PHYSICAL REVIEW LETTERS 2012; 109:263001. [PMID: 23368555 DOI: 10.1103/physrevlett.109.263001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Indexed: 05/23/2023]
Abstract
We investigate molecular dynamics of multiple ionization in N2 through multiple core-level photoabsorption and subsequent Auger decay processes induced by intense, short x-ray free electron laser pulses. The timing dynamics of the photoabsorption and dissociation processes is mapped onto the kinetic energy of the fragments. Measurements of the latter allow us to map out the average internuclear separation for every molecular photoionization sequence step and obtain the average time interval between the photoabsorption events. Using multiphoton ionization as a tool of the multiple-pulse pump-probe scheme, we demonstrate the modification of the ionization dynamics as we vary the x-ray laser pulse duration.
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Petrović VS, Siano M, White JL, Berrah N, Bostedt C, Bozek JD, Broege D, Chalfin M, Coffee RN, Cryan J, Fang L, Farrell JP, Frasinski LJ, Glownia JM, Gühr M, Hoener M, Holland DMP, Kim J, Marangos JP, Martinez T, McFarland BK, Minns RS, Miyabe S, Schorb S, Sension RJ, Spector LS, Squibb R, Tao H, Underwood JG, Bucksbaum PH. Transient X-ray fragmentation: probing a prototypical photoinduced ring opening. PHYSICAL REVIEW LETTERS 2012; 108:253006. [PMID: 23004597 DOI: 10.1103/physrevlett.108.253006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Indexed: 05/23/2023]
Abstract
We report the first study of UV-induced photoisomerization probed via core ionization by an x-ray laser. We investigated x-ray ionization and fragmentation of the cyclohexadiene-hexatriene system at 850 eV during the ring opening. We find that the ion-fragmentation patterns evolve over a picosecond, reflecting a change in the state of excitation and the molecular geometry: the average kinetic energy per ion fragment and H(+)-ion count increase as the ring opens and the molecule elongates. We discuss new opportunities for molecular photophysics created by optical pump x-ray probe experiments.
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34
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Kanter EP, Krässig B, Li Y, March AM, Ho P, Rohringer N, Santra R, Southworth SH, DiMauro LF, Doumy G, Roedig CA, Berrah N, Fang L, Hoener M, Bucksbaum PH, Ghimire S, Reis DA, Bozek JD, Bostedt C, Messerschmidt M, Young L. Unveiling and driving hidden resonances with high-fluence, high-intensity x-ray pulses. PHYSICAL REVIEW LETTERS 2011; 107:233001. [PMID: 22182083 DOI: 10.1103/physrevlett.107.233001] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Indexed: 05/24/2023]
Abstract
We show that high fluence, high-intensity x-ray pulses from the world's first hard x-ray free-electron laser produce nonlinear phenomena that differ dramatically from the linear x-ray-matter interaction processes that are encountered at synchrotron x-ray sources. We use intense x-ray pulses of sub-10-fs duration to first reveal and subsequently drive the 1s↔2p resonance in singly ionized neon. This photon-driven cycling of an inner-shell electron modifies the Auger decay process, as evidenced by line shape modification. Our work demonstrates the propensity of high-fluence, femtosecond x-ray pulses to alter the target within a single pulse, i.e., to unveil hidden resonances, by cracking open inner shells energetically inaccessible via single-photon absorption, and to consequently trigger damaging electron cascades at unexpectedly low photon energies.
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35
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Kim J, Tao H, White JL, Petrović VS, Martinez TJ, Bucksbaum PH. Control of 1,3-Cyclohexadiene Photoisomerization Using Light-Induced Conical Intersections. J Phys Chem A 2011; 116:2758-63. [DOI: 10.1021/jp208384b] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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36
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Farrell JP, Petretti S, Förster J, McFarland BK, Spector LS, Vanne YV, Decleva P, Bucksbaum PH, Saenz A, Gühr M. Strong field ionization to multiple electronic states in water. PHYSICAL REVIEW LETTERS 2011; 107:083001. [PMID: 21929165 DOI: 10.1103/physrevlett.107.083001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Indexed: 05/31/2023]
Abstract
High harmonic spectra show that laser-induced strong field ionization of water has a significant contribution from an inner-valence orbital. Our experiment uses the ratio of H(2)O and D(2)O high harmonic yields to isolate the characteristic nuclear motion of the molecular ionic states. The nuclear motion initiated via ionization of the highest occupied molecular orbital (HOMO) is small and is expected to lead to similar harmonic yields for the two isotopes. In contrast, ionization of the second least bound orbital (HOMO-1) exhibits itself via a strong bending motion which creates a significant isotope effect. We elaborate on this interpretation by solving the time-dependent Schrödinger equation to simulate strong field ionization and high harmonic generation from the water isotopes. We expect that this isotope marking scheme for probing excited ionic states in strong field processes can be generalized to other molecules.
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37
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Abstract
AbstractStatistical thermodynamics is used to derive the reaction rate for melting and freezing by considering an atomically sharp interface with or without an activated intermediate state. The resulting predictions differ substantially from those of the classical kinetic rate theory at large deviations from equilibrium. The model may be appropriate for the analysis of pulsed laser melting experiments where large deviations are expected.
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38
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Doumy G, Roedig C, Son SK, Blaga CI, DiChiara AD, Santra R, Berrah N, Bostedt C, Bozek JD, Bucksbaum PH, Cryan JP, Fang L, Ghimire S, Glownia JM, Hoener M, Kanter EP, Krässig B, Kuebel M, Messerschmidt M, Paulus GG, Reis DA, Rohringer N, Young L, Agostini P, DiMauro LF. Nonlinear atomic response to intense ultrashort x rays. PHYSICAL REVIEW LETTERS 2011; 106:083002. [PMID: 21405568 DOI: 10.1103/physrevlett.106.083002] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Indexed: 05/11/2023]
Abstract
The nonlinear absorption mechanisms of neon atoms to intense, femtosecond kilovolt x rays are investigated. The production of Ne(9+) is observed at x-ray frequencies below the Ne(8+), 1s(2) absorption edge and demonstrates a clear quadratic dependence on fluence. Theoretical analysis shows that the production is a combination of the two-photon ionization of Ne(8+) ground state and a high-order sequential process involving single-photon production and ionization of transient excited states on a time scale faster than the Auger decay. We find that the nonlinear direct two-photon ionization cross section is orders of magnitude higher than expected from previous calculations.
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39
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Cryan JP, Glownia JM, Andreasson J, Belkacem A, Berrah N, Blaga CI, Bostedt C, Bozek J, Buth C, DiMauro LF, Fang L, Gessner O, Guehr M, Hajdu J, Hertlein MP, Hoener M, Kornilov O, Marangos JP, March AM, McFarland BK, Merdji H, Petrović VS, Raman C, Ray D, Reis D, Tarantelli F, Trigo M, White JL, White W, Young L, Bucksbaum PH, Coffee RN. Auger electron angular distribution of double core-hole states in the molecular reference frame. PHYSICAL REVIEW LETTERS 2010; 105:083004. [PMID: 20868096 DOI: 10.1103/physrevlett.105.083004] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Indexed: 05/29/2023]
Abstract
The Linac Coherent Light Source free electron laser is a source of high brightness x rays, 2×10(11) photons in a ∼5 fs pulse, that can be focused to produce double core vacancies through rapid sequential ionization. This enables double core vacancy Auger electron spectroscopy, an entirely new way to study femtosecond chemical dynamics with Auger electrons that probe the local valence structure of molecules near a specific atomic core. Using 1.1 keV photons for sequential x-ray ionization of impulsively aligned molecular nitrogen, we observed a rich single-site double core vacancy Auger electron spectrum near 413 eV, in good agreement with ab initio calculations, and we measured the corresponding Auger electron angle dependence in the molecular frame.
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40
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Fang L, Hoener M, Gessner O, Tarantelli F, Pratt ST, Kornilov O, Buth C, Gühr M, Kanter EP, Bostedt C, Bozek JD, Bucksbaum PH, Chen M, Coffee R, Cryan J, Glownia M, Kukk E, Leone SR, Berrah N. Double core-hole production in N2: beating the Auger clock. PHYSICAL REVIEW LETTERS 2010; 105:083005. [PMID: 20868097 DOI: 10.1103/physrevlett.105.083005] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Indexed: 05/29/2023]
Abstract
We investigate the creation of double K-shell holes in N2 molecules via sequential absorption of two photons on a time scale shorter than the core-hole lifetime by using intense x-ray pulses from the Linac Coherent Light Source free electron laser. The production and decay of these states is characterized by photoelectron spectroscopy and Auger electron spectroscopy. In molecules, two types of double core holes are expected, the first with two core holes on the same N atom, and the second with one core hole on each N atom. We report the first direct observations of the former type of core hole in a molecule, in good agreement with theory, and provide an experimental upper bound for the relative contribution of the latter type.
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41
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Glownia JM, Cryan J, Andreasson J, Belkacem A, Berrah N, Blaga CI, Bostedt C, Bozek J, DiMauro LF, Fang L, Frisch J, Gessner O, Gühr M, Hajdu J, Hertlein MP, Hoener M, Huang G, Kornilov O, Marangos JP, March AM, McFarland BK, Merdji H, Petrovic VS, Raman C, Ray D, Reis DA, Trigo M, White JL, White W, Wilcox R, Young L, Coffee RN, Bucksbaum PH. Time-resolved pump-probe experiments at the LCLS. OPTICS EXPRESS 2010; 18:17620-30. [PMID: 20721148 DOI: 10.1364/oe.18.017620] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The first time-resolved x-ray/optical pump-probe experiments at the SLAC Linac Coherent Light Source (LCLS) used a combination of feedback methods and post-analysis binning techniques to synchronize an ultrafast optical laser to the linac-based x-ray laser. Transient molecular nitrogen alignment revival features were resolved in time-dependent x-ray-induced fragmentation spectra. These alignment features were used to find the temporal overlap of the pump and probe pulses. The strong-field dissociation of x-ray generated quasi-bound molecular dications was used to establish the residual timing jitter. This analysis shows that the relative arrival time of the Ti:Sapphire laser and the x-ray pulses had a distribution with a standard deviation of approximately 120 fs. The largest contribution to the jitter noise spectrum was the locking of the laser oscillator to the reference RF of the accelerator, which suggests that simple technical improvements could reduce the jitter to better than 50 fs.
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42
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Young L, Kanter EP, Krässig B, Li Y, March AM, Pratt ST, Santra R, Southworth SH, Rohringer N, Dimauro LF, Doumy G, Roedig CA, Berrah N, Fang L, Hoener M, Bucksbaum PH, Cryan JP, Ghimire S, Glownia JM, Reis DA, Bozek JD, Bostedt C, Messerschmidt M. Femtosecond electronic response of atoms to ultra-intense X-rays. Nature 2010; 466:56-61. [PMID: 20596013 DOI: 10.1038/nature09177] [Citation(s) in RCA: 262] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 05/10/2010] [Indexed: 11/09/2022]
Abstract
An era of exploring the interactions of high-intensity, hard X-rays with matter has begun with the start-up of a hard-X-ray free-electron laser, the Linac Coherent Light Source (LCLS). Understanding how electrons in matter respond to ultra-intense X-ray radiation is essential for all applications. Here we reveal the nature of the electronic response in a free atom to unprecedented high-intensity, short-wavelength, high-fluence radiation (respectively 10(18) W cm(-2), 1.5-0.6 nm, approximately 10(5) X-ray photons per A(2)). At this fluence, the neon target inevitably changes during the course of a single femtosecond-duration X-ray pulse-by sequentially ejecting electrons-to produce fully-stripped neon through absorption of six photons. Rapid photoejection of inner-shell electrons produces 'hollow' atoms and an intensity-induced X-ray transparency. Such transparency, due to the presence of inner-shell vacancies, can be induced in all atomic, molecular and condensed matter systems at high intensity. Quantitative comparison with theory allows us to extract LCLS fluence and pulse duration. Our successful modelling of X-ray/atom interactions using a straightforward rate equation approach augurs favourably for extension to complex systems.
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43
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Meyer DA, Kwiat PG, Hughes RJ, Bucksbaum PH, Ahn J, Weinacht TC. Does Rydberg state manipulation equal quantum computation? Science 2010; 289:1431a. [PMID: 17839509 DOI: 10.1126/science.289.5484.1431a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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44
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Hoener M, Fang L, Kornilov O, Gessner O, Pratt ST, Gühr M, Kanter EP, Blaga C, Bostedt C, Bozek JD, Bucksbaum PH, Buth C, Chen M, Coffee R, Cryan J, Dimauro L, Glownia M, Hosler E, Kukk E, Leone SR, McFarland B, Messerschmidt M, Murphy B, Petrovic V, Rolles D, Berrah N. Ultraintense x-ray induced ionization, dissociation, and frustrated absorption in molecular nitrogen. PHYSICAL REVIEW LETTERS 2010; 104:253002. [PMID: 20867372 DOI: 10.1103/physrevlett.104.253002] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Indexed: 05/11/2023]
Abstract
Sequential multiple photoionization of the prototypical molecule N2 is studied with femtosecond time resolution using the Linac Coherent Light Source (LCLS). A detailed picture of intense x-ray induced ionization and dissociation dynamics is revealed, including a molecular mechanism of frustrated absorption that suppresses the formation of high charge states at short pulse durations. The inverse scaling of the average target charge state with x-ray peak brightness has possible implications for single-pulse imaging applications.
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45
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Farrell JP, Spector LS, Gaarde MB, McFarland BK, Bucksbaum PH, Gühr M. Strongly dispersive transient Bragg grating for high harmonics. OPTICS LETTERS 2010; 35:2028-2030. [PMID: 20548375 DOI: 10.1364/ol.35.002028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We create a transient Bragg grating in a high-harmonic generation medium using two counterpropagating pulses. The Bragg grating disperses the harmonics in angle and can diffract a large bandwidth with temporal resolution limited only by the source size.
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46
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Farrell JP, McFarland BK, Bucksbaum PH, Gühr M. Calibration of a high harmonic spectrometer by laser induced plasma emission. OPTICS EXPRESS 2009; 17:15134-15144. [PMID: 19687991 DOI: 10.1364/oe.17.015134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We present a method that allows for a convenient switching between high harmonic generation (HHG) and accurate calibration of the vacuum ultraviolet (VUV) spectrometer used to analyze the harmonic spectrum. The accurate calibration of HHG spectra is becoming increasingly important for the determination of electronic structures. The wavelength of the laser harmonics themselves depend on the details of the harmonic geometry and phase matching, making them unsuitable for calibration purposes. In our calibration mode, the target resides directly at the focus of the laser, thereby enhancing plasma emission and suppressing harmonic generation. In HHG mode, the source medium resides in front or after the focus, showing enhanced HHG and no plasma emission lines. We analyze the plasma emission and use it for a direct calibration of our HHG spectra.
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47
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Ravasio A, Gauthier D, Maia FRNC, Billon M, Caumes JP, Garzella D, Géléoc M, Gobert O, Hergott JF, Pena AM, Perez H, Carré B, Bourhis E, Gierak J, Madouri A, Mailly D, Schiedt B, Fajardo M, Gautier J, Zeitoun P, Bucksbaum PH, Hajdu J, Merdji H. Single-shot diffractive imaging with a table-top femtosecond soft x-ray laser-harmonics source. PHYSICAL REVIEW LETTERS 2009; 103:028104. [PMID: 19659250 DOI: 10.1103/physrevlett.103.028104] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Indexed: 05/24/2023]
Abstract
Coherent x-ray diffractive imaging is a powerful method for studies on nonperiodic structures on the nanoscale. Access to femtosecond dynamics in major physical, chemical, and biological processes requires single-shot diffraction data. Up to now, this has been limited to intense coherent pulses from a free electron laser. Here we show that laser-driven ultrashort x-ray sources offer a comparatively inexpensive alternative. We present measurements of single-shot diffraction patterns from isolated nano-objects with a single 20 fs pulse from a table-top high-harmonic x-ray laser. Images were reconstructed with a resolution of 119 nm from the single shot and 62 nm from multiple shots.
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48
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Carroll EC, White JL, Florean AC, Bucksbaum PH, Sension RJ. Multiphoton Control of the 1,3-Cyclohexadiene Ring-Opening Reaction in the Presence of Competing Solvent Reactions. J Phys Chem A 2008; 112:6811-22. [DOI: 10.1021/jp8013404] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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49
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Carroll EC, Florean AC, Bucksbaum PH, Spears KG, Sension RJ. Phase control of the competition between electronic transitions in a solvated laser dye. Chem Phys 2008. [DOI: 10.1016/j.chemphys.2008.01.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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50
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Lindenberg AM, Engemann S, Gaffney KJ, Sokolowski-Tinten K, Larsson J, Hillyard PB, Reis DA, Fritz DM, Arthur J, Akre RA, George MJ, Deb A, Bucksbaum PH, Hajdu J, Meyer DA, Nicoul M, Blome C, Tschentscher T, Cavalieri AL, Falcone RW, Lee SH, Pahl R, Rudati J, Fuoss PH, Nelson AJ, Krejcik P, Siddons DP, Lorazo P, Hastings JB. X-ray diffuse scattering measurements of nucleation dynamics at femtosecond resolution. PHYSICAL REVIEW LETTERS 2008; 100:135502. [PMID: 18517965 DOI: 10.1103/physrevlett.100.135502] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Indexed: 05/26/2023]
Abstract
Femtosecond time-resolved small and wide angle x-ray diffuse scattering techniques are applied to investigate the ultrafast nucleation processes that occur during the ablation process in semiconducting materials. Following intense optical excitation, a transient liquid state of high compressibility characterized by large-amplitude density fluctuations is observed and the buildup of these fluctuations is measured in real time. Small-angle scattering measurements reveal snapshots of the spontaneous nucleation of nanoscale voids within a metastable liquid and support theoretical predictions of the ablation process.
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