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Kang S, Jung KH, Mhin S, Son Y, Lee K, Kim WR, Choi H, Ryu JH, Han H, Kim KM. Fundamental Understanding of the Formation Mechanism for Graphene Quantum Dots Fabricated by Pulsed Laser Fragmentation in Liquid: Experimental and Theoretical Insight. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2003538. [PMID: 32830432 DOI: 10.1002/smll.202003538] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/06/2020] [Indexed: 05/21/2023]
Abstract
The pulsed laser fragmentation in liquid (PLFL) process is a promising technique for the synthesis of carbon-based functional materials. In particular, there has been considerable attention on graphene quantum dots (GQDs) derived from multiwalled carbon nanotubes (MWCNTs) by the PLFL process, owing to the low cost and rapid processing time involved. However, a fundamental deep understanding of the formation of GQDs from MWCNTs by PLFL has still not been achieved despite the high demand. In this work, a mechanism for the formation of GQDs from MWCNTs by the PLFL process is reported, through the combination of experimental and theoretical studies. Both the experimental and computational results demonstrate that the formation of GQDs strongly depends on the pulse laser energy. Both methods demonstrate that the critical energy point, where a plasma plume is generated on the surface of the MWCNTs, should be precisely maintained to produce GQDs; otherwise, an amorphous carbon structure is favorably formed from the scattered carbons.
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Affiliation(s)
- Sukhyun Kang
- Korea Institute of Industrial Technology (KITECH), 137-41 Gwahakdanji-ro, Gangneung, Gangwon, 25440, Republic of Korea
| | - Kyung Hwan Jung
- Korea Institute of Industrial Technology (KITECH), 137-41 Gwahakdanji-ro, Gangneung, Gangwon, 25440, Republic of Korea
| | - Sungwook Mhin
- Department of Advanced Materials Engineering, Kyonggi University, Suwon, 16227, Korea
| | - Yong Son
- Korea Institute of Industrial Technology (KITECH), 113-58, Seohaean-ro, Siheung-si, Gyeonggi-do, 15014, Republic of Korea
| | - Kangpyo Lee
- Korea Institute of Industrial Technology (KITECH), 137-41 Gwahakdanji-ro, Gangneung, Gangwon, 25440, Republic of Korea
| | - Won Rae Kim
- Korea Institute of Industrial Technology (KITECH), 137-41 Gwahakdanji-ro, Gangneung, Gangwon, 25440, Republic of Korea
| | - Heechae Choi
- Theoretical Materials and Chemistry Group, Institute of Inorganic Chemistry, University of Cologne, Greinstr. 6, Cologne, 50939, Germany
| | - Jeong Ho Ryu
- Department of Materials science and Engineering, Korea National University of Transportation, 50 Daehak-ro, Chungju-si, Chungbuk, 27469, Republic of Korea
| | - Hyuksu Han
- Department of Energy Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, Republic of Korea
| | - Kang Min Kim
- Korea Institute of Industrial Technology (KITECH), 137-41 Gwahakdanji-ro, Gangneung, Gangwon, 25440, Republic of Korea
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2
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Nairat M, Lozovoy VV, Dantus M. Order of Magnitude Dissociative Ionization Enhancement Observed for Pulses with High Order Dispersion. J Phys Chem A 2016; 120:8529-8536. [PMID: 27744700 DOI: 10.1021/acs.jpca.6b08659] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
While the interaction of atoms in strong fields is well understood, the same cannot be said about molecules. We consider how dissociative ionization of molecules depends on the quality of the femtosecond laser pulses, in particular, the presence of third- and fourth-order dispersion. We find that high-order dispersion (HOD) unexpectedly results in order-of-magnitude enhanced ion yields, along with the factor of 3 greater kinetic energy release compared to transform-limited pulses with equal peak intensities. The magnitude of these effects is not caused by increased pulse duration. We evaluate the role of pulse pedestals produced by HOD and other pulse shaping approaches, for a number of molecules including acetylene, methanol, methylene chloride, acetonitrile, toluene, and o-nitrotoluene, and discuss our findings in terms of processes such as prealignment, preionization, and bond softening. We conclude, based on the quasi-symmetric temporal dependence of the observed enhancements that cascade ionization is likely responsible for the large accumulation of charge prior to the ejection of energetic fragments along the laser polarization axis.
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Affiliation(s)
- Muath Nairat
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States
| | - Vadim V Lozovoy
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States
| | - Marcos Dantus
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States.,Department of Physics and Astronomy, Michigan State University , East Lansing, Michigan 48824, United States
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3
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Xie X, Lötstedt E, Roither S, Schöffler M, Kartashov D, Midorikawa K, Baltuška A, Yamanouchi K, Kitzler M. Duration of an intense laser pulse can determine the breakage of multiple chemical bonds. Sci Rep 2015; 5:12877. [PMID: 26271602 PMCID: PMC4536518 DOI: 10.1038/srep12877] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 07/13/2015] [Indexed: 11/29/2022] Open
Abstract
Control over the breakage of a certain chemical bond in a molecule by an ultrashort laser pulse has been considered for decades. With the availability of intense non-resonant laser fields it became possible to pre-determine femtosecond to picosecond molecular bond breakage dynamics by controlled distortions of the electronic molecular system on sub-femtosecond time scales using field-sensitive processes such as strong-field ionization or excitation. So far, all successful demonstrations in this area considered only fragmentation reactions, where only one bond is broken and the molecule is split into merely two moieties. Here, using ethylene (C2H4) as an example, we experimentally investigate whether complex fragmentation reactions that involve the breakage of more than one chemical bond can be influenced by parameters of an ultrashort intense laser pulse. We show that the dynamics of removing three electrons by strong-field ionization determines the ratio of fragmentation of the molecular trication into two respectively three moieties. We observe a relative increase of two-body fragmentations with the laser pulse duration by almost an order of magnitude. Supported by quantum chemical simulations we explain our experimental results by the interplay between the dynamics of electron removal and nuclear motion.
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Affiliation(s)
- Xinhua Xie
- Photonics Institute, Vienna University of Technology, Gusshausstrasse 27, A-1040 Vienna, Austria, EU
| | - Erik Lötstedt
- Laser Technology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Stefan Roither
- Photonics Institute, Vienna University of Technology, Gusshausstrasse 27, A-1040 Vienna, Austria, EU
| | - Markus Schöffler
- Photonics Institute, Vienna University of Technology, Gusshausstrasse 27, A-1040 Vienna, Austria, EU
| | - Daniil Kartashov
- Photonics Institute, Vienna University of Technology, Gusshausstrasse 27, A-1040 Vienna, Austria, EU
| | - Katsumi Midorikawa
- Laser Technology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Andrius Baltuška
- Photonics Institute, Vienna University of Technology, Gusshausstrasse 27, A-1040 Vienna, Austria, EU
| | - Kaoru Yamanouchi
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Markus Kitzler
- Photonics Institute, Vienna University of Technology, Gusshausstrasse 27, A-1040 Vienna, Austria, EU
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4
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Hydrogen Migration in Intense Laser Fields: Analysis and Control in Concert. SPRINGER SERIES IN CHEMICAL PHYSICS 2015. [DOI: 10.1007/978-3-319-06731-5_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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5
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Konar A, Shu Y, Lozovoy VV, Jackson JE, Levine BG, Dantus M. Polyatomic molecules under intense femtosecond laser irradiation. J Phys Chem A 2014; 118:11433-50. [PMID: 25314590 DOI: 10.1021/jp505498t] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Interaction of intense laser pulses with atoms and molecules is at the forefront of atomic, molecular, and optical physics. It is the gateway to powerful new tools that include above threshold ionization, high harmonic generation, electron diffraction, molecular tomography, and attosecond pulse generation. Intense laser pulses are ideal for probing and manipulating chemical bonding. Though the behavior of atoms in strong fields has been well studied, molecules under intense fields are not as well understood and current models have failed in certain important aspects. Molecules, as opposed to atoms, present confounding possibilities of nuclear and electronic motion upon excitation. The dynamics and fragmentation patterns in response to the laser field are structure sensitive; therefore, a molecule cannot simply be treated as a "bag of atoms" during field induced ionization. In this article we present a set of experiments and theoretical calculations exploring the behavior of a large collection of aryl alkyl ketones when irradiated with intense femtosecond pulses. Specifically, we consider to what extent molecules retain their molecular identity and properties under strong laser fields. Using time-of-flight mass spectrometry in conjunction with pump-probe techniques we study the dynamical behavior of these molecules, monitoring ion yield modulation caused by intramolecular motions post ionization. The set of molecules studied is further divided into smaller sets, sorted by type and position of functional groups. The pump-probe time-delay scans show that among positional isomers the variations in relative energies, which amount to only a few hundred millielectronvolts, influence the dynamical behavior of the molecules despite their having experienced such high fields (V/Å). High level ab initio quantum chemical calculations were performed to predict molecular dynamics along with single and multiphoton resonances in the neutral and ionic states. We propose the following model of strong-field ionization and subsequent fragmentation for polyatomic molecules: Single electron ionization occurs on a suboptical cycle time scale, and the electron carries away essentially all of the energy, leaving behind little internal energy in the cation. Subsequent fragmentation of the cation takes place as a result of further photon absorption modulated by one- and two-photon resonances, which provide sufficient energy to overcome the dissociation energy. The proposed hypothesis implies the loss of a photoelectron at a rate that is faster than intramolecular vibrational relaxation and is consistent with the observation of nonergodic photofragmentation of polyatomic molecules as well as experimental results from many other research groups on different molecules and with different pulse durations and wavelengths.
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Affiliation(s)
- Arkaprabha Konar
- Department of Chemistry and ‡Department of Physics and Astronomy, Michigan State University , East Lansing, Michigan 48824, United States
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6
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Karimi R, Bisson É, Wales B, Walles B, Beaulieu S, Giguère M, Long Z, Liu WK, Kieffer JC, Légaré F, Sanderson J. N2O ionization and dissociation dynamics in intense femtosecond laser radiation, probed by systematic pulse length variation from 7 to 500 fs. J Chem Phys 2013; 138:204311. [PMID: 23742479 DOI: 10.1063/1.4804653] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have made a series of measurements, as a function of pulse duration, of ionization and fragmentation of the asymmetric molecule N2O in intense femtosecond laser radiation. The pulse length was varied from 7 fs to 500 fs with intensity ranging from 4 × 10(15) to 2.5 × 10(14) W∕cm(2). Time and position sensitive detection allows us to observe all fragments in coincidence. By representing the final dissociation geometry with Dalitz plots, we can identify the underlying breakup dynamics. We observe for the first time that there are two stepwise dissociation pathways for N2O(3+): (1) N2O(3+) → N(+) + NO(2+) → N(+) + N(+) + O(+) and (2) N2O(3+) → N2 (2+) + O(+) → N(+) + N(+) + O(+) as well as one for N2O(4+) → N(2+) + NO(2+) → N(2+) + N(+) + O(+). The N2 (2+) stepwise channel is suppressed for longer pulse length, a phenomenon which we attribute to the influence which the structure of the 3+ potential has on the dissociating wave packet propagation. Finally, by observing the total kinetic energy released for each channel as a function of pulse duration, we show the increasing importance of charge resonance enhanced ionization for channels higher than 3+.
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Affiliation(s)
- Reza Karimi
- Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
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7
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Goswami T, Das DK, Goswami D. Controlling the femtosecond laser-driven transformation of dicyclopentadiene into cyclopentadiene. Chem Phys Lett 2013; 558:1-7. [PMID: 24098059 PMCID: PMC3790071 DOI: 10.1016/j.cplett.2012.10.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Dynamics of the chemical transformation of dicyclopentadiene into cyclopentadiene in a supersonic molecular beam is elucidated using femtosecond time-resolved degenerate pump-probe mass spectrometry. Control of this ultrafast chemical reaction is achieved by using linearly chirped frequency modulated pulses. We show that negatively chirped femtosecond laser pulses enhance the cyclopentadiene photo-product yield by an order of magnitude as compared to that of the unmodulated or the positively chirped pulses. This demonstrates that the phase structure of femtosecond laser pulse plays an important role in determining the outcome of a chemical reaction.
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Affiliation(s)
| | - Dipak K. Das
- Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
| | - Debabrata Goswami
- Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
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8
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Schirmel N, Reusch N, Horsch P, Weitzel KM. Formation of fragment ions (H+, H3+, CH3+) from ethane in intense femtosecond laser fields – from understanding to control. Faraday Discuss 2013; 163:461-74; discussion 513-43. [DOI: 10.1039/c3fd20152j] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Goswami T, Das DK, Kumar SKK, Goswami D. Chirp and polarization control of femtosecond molecular fragmentation. INDIAN JOURNAL OF PHYSICS AND PROCEEDINGS OF THE INDIAN ASSOCIATION FOR THE CULTIVATION OF SCIENCE (2004) 2012; 86:181-185. [PMID: 24115807 PMCID: PMC3792555 DOI: 10.1007/s12648-012-0039-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We explore the simultaneous effect of chirp and polarization as the two control parameters for non-resonant photo-dissociation of n-propyl benzene. Experiments performed over a wide range of laser intensities show that these two control knobs behave mutually exclusively. Specifically, for the coherently enhanced fragments (C3H3+, C5H5+) with negatively chirped pulses and C6H5+ with positively chirped pulses, polarization effect is the same as compared to that in the case of transform-limited pulses. Though a change in polarization affects the overall fragmentation efficiency, the fragmentation pattern of n-propyl benzene molecule remains unaffected in contrast to the chirp case.
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Affiliation(s)
- T Goswami
- Department of Chemistry, Indian Institute of Technology, Kanpur 208 016, Uttar Pradesh, India
| | - D K Das
- Department of Chemistry, Indian Institute of Technology, Kanpur 208 016, Uttar Pradesh, India
| | - S K Karthick Kumar
- Department of Chemistry, Indian Institute of Technology, Kanpur 208 016, Uttar Pradesh, India
| | - D Goswami
- Department of Chemistry, Indian Institute of Technology, Kanpur 208 016, Uttar Pradesh, India
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10
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Xu H, Okino T, Kudou T, Yamanouchi K, Roither S, Kitzler M, Baltuska A, Chin SL. Effect of Laser Parameters on Ultrafast Hydrogen Migration in Methanol Studied by Coincidence Momentum Imaging. J Phys Chem A 2011; 116:2686-90. [DOI: 10.1021/jp207483y] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Huailiang Xu
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China
| | - Tomoya Okino
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tatsuya Kudou
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kaoru Yamanouchi
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Stefan Roither
- Photonics Institute, Vienna University of Technology, Gusshausstrasse 27, A-1040 Vienna, Austria
| | - Markus Kitzler
- Photonics Institute, Vienna University of Technology, Gusshausstrasse 27, A-1040 Vienna, Austria
| | - Andrius Baltuska
- Photonics Institute, Vienna University of Technology, Gusshausstrasse 27, A-1040 Vienna, Austria
| | - See-Leang Chin
- Center for Optics, Photonics and Laser (COPL) & Department of Physics, Engineering Physics and Optics, Laval University, Quebec City, QC, Canada G1 V 0A6
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11
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Tamenori Y, Okada K, Tabayashi K, Hiraya A, Gejo T, Honma K. Photodissociation investigation of doubly charged ethanol clusters induced by inner-shell electron ionization. J Chem Phys 2011; 134:204302. [DOI: 10.1063/1.3590164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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12
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13
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Kato T, Yamanouchi K. Time-dependent multiconfiguration theory for describing molecular dynamics in diatomic-like molecules. J Chem Phys 2009; 131:164118. [DOI: 10.1063/1.3249967] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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14
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Tanaka M, Kawaji M, Yatsuhashi T, Nakashima N. Ionization and Fragmentation of Alkylphenols by 0.8−1.5 μm Femtosecond Laser Pulses. J Phys Chem A 2009; 113:12056-62. [DOI: 10.1021/jp902557v] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michinori Tanaka
- Department of Chemistry, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan
| | - Mariko Kawaji
- Department of Chemistry, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan
| | - Tomoyuki Yatsuhashi
- Department of Chemistry, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan
| | - Nobuaki Nakashima
- Department of Chemistry, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan
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15
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Goswami T, Karthick Kumar SK, Dutta A, Goswami D. Control of laser induced molecular fragmentation of n-propyl benzene using chirped femtosecond laser pulses. Chem Phys 2009; 360:47-52. [PMID: 19696899 PMCID: PMC2722903 DOI: 10.1016/j.chemphys.2009.04.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2008] [Accepted: 04/16/2009] [Indexed: 10/30/2022]
Abstract
We present the effect of chirping a femtosecond laser pulse on the fragmentation of n-propyl benzene. An enhancement of an order of magnitude for the relative yields of C3H3+ and C5H5+ in the case of negatively chirped pulses and C6H5+ in the case of positively chirped pulses with respect to the transform-limited pulse indicates that in some fragmentation channel, coherence of the laser field plays an important role. For the relative yield of all other heavier fragment ions, resulting from the interaction of the intense laser field with the molecule, there is no such enhancement effect with the sign of chirp, within experimental errors. The importance of the laser phase is further reinforced through a direct comparison of the fragmentation results with the second harmonic of the chirped laser pulse with identical bandwidth.
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Affiliation(s)
- Tapas Goswami
- Department of Chemistry, Indian Institute of Technology Kanpur, UP 208016, India
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16
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Photoelectron–photoion coincidence momentum imaging for dissociative ionization of ethanol in intense laser fields. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Wavepacket Dynamics of Molecules in Intense Laser Fields. SPRINGER SERIES IN CHEMICAL PHYSICS 2009. [DOI: 10.1007/978-3-540-69143-3_3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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18
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Lozovoy VV, Zhu X, Gunaratne TC, Harris DA, Shane JC, Dantus M. Control of Molecular Fragmentation Using Shaped Femtosecond Pulses. J Phys Chem A 2008; 112:3789-812. [DOI: 10.1021/jp071691p] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Vadim V. Lozovoy
- Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824
| | - Xin Zhu
- Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824
| | - Tissa C. Gunaratne
- Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824
| | - D. Ahmasi Harris
- Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824
| | - Janelle C. Shane
- Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824
| | - Marcos Dantus
- Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824
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19
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Pearson BJ, Nichols SR, Weinacht T. Molecular fragmentation driven by ultrafast dynamic ionic resonances. J Chem Phys 2007; 127:131101. [DOI: 10.1063/1.2790419] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Yazawa H, Shioyama T, Suda Y, Yamanaka M, Kannari F, Itakura R, Yamanouchi K. Controlling the dissociative ionization of ethanol with 800 and 400nm two-color femtosecond laser pulses. J Chem Phys 2007; 127:124312. [PMID: 17902908 DOI: 10.1063/1.2780156] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ethanol molecules were irradiated with a pair of temporally overlapping ultrashort intense laser pulses (10(13)-10(14) Wcm(2)) with different colors of 400 and 800 nm, and the dissociative ionization processes have been investigated. The yield ratio of the C-O bond breaking with respect to the C-C bond breaking was varied in the range of 0.17-0.53 sensitively depending on the delay time between the two laser pulses, and the absolute value of the yield of the C-O bond breaking was found to be increased largely when the Fourier-transform limited 800 nm laser pulse overlaps the stretched 400 nm laser pulse, demonstrating an advantage of the two-color intense laser fields in controlling chemical bond breaking processes.
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Affiliation(s)
- H Yazawa
- Department of Electronics and Electrical Engineering, Faculty of Science and Technologies, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
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21
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Ab initio molecular dynamics and wavepacket dynamics of highly charged fullerene cations produced with intense near-infrared laser pulses. Chem Phys 2007. [DOI: 10.1016/j.chemphys.2007.04.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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22
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Lu HF, Li FY, Lin CC, Nagaya K, Chao I, Lin S. The fragmentation of ethanol cation under an electric field: An ab initio/RRKM study. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.06.063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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23
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Mai FD, Lu HF, Li FY, Lin SH. Fragmentations of Hydroxymethyl Radical Cation: An Ab Initio Study. J CHIN CHEM SOC-TAIP 2007. [DOI: 10.1002/jccs.200700042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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24
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25
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Hishikawa A, Takahashi EJ, Matsuda A. Electronic and nuclear responses of fixed-in-space H2S to ultrashort intense laser fields. PHYSICAL REVIEW LETTERS 2006; 97:243002. [PMID: 17280276 DOI: 10.1103/physrevlett.97.243002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Indexed: 05/13/2023]
Abstract
The Coulomb explosion dynamics of H2S, H2S3+-->H+ +S+ + H+, in ultrashort intense laser fields (12 fs, approximately 2 x 10(14) W/cm2) is studied by the coincidence momentum imaging of the three fragment ions. Different electronic and nuclear responses are identified depending on the direction of laser polarization epsilon in the molecular frame. The dependence can be interpreted in terms of the electronic and bonding characters of charge transfer states of H2S coupled to the electronic ground state.
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Affiliation(s)
- Akiyoshi Hishikawa
- Institute for Molecular Science, National Institutes of Natural Sciences, Myodaiji, Okazaki, Aichi 444-8585, Japan.
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26
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Yazawa H, Shioyama T, Suda Y, Kannari F, Itakura R, Yamanouchi K. Dissociative ionization of ethanol by 400nm femtosecond laser pulses. J Chem Phys 2006; 125:184311. [PMID: 17115756 DOI: 10.1063/1.2387177] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The dissociative ionization of ethanol in short-pulsed laser fields at approximately 400 nm is investigated. The yield ratio of the C-O bond breaking with respect to the C-C bond breaking increases sharply as the temporal width increases from 60 to 400 fs, and the yield ratio is two to three times as large as that at 800 nm in the entire pulse-width range of 60-580 fs. The enhancement of the C-O bond breaking of singly charged ethanol at 400 nm and the bond elongation prior to the Coulomb explosion of doubly charged ethanol occurring in the relatively weak light field intensity of 10(12)-10(13) W cm(2) is interpreted by the efficient light-induced coupling among the electronic states at the shorter wavelength of 400 nm. From the double pulse experiment, in which ethanol is irradiated with a pair of short pulses (<80 fs), the most efficient coupling occurs at Deltat=160 fs that is much earlier than Deltat=250 at 800 nm, where Deltat denotes the temporal separation of the two pulses, indicating that the nonadiabatic field-induced potential crossings of singly charged ethanol occurs much earlier at 400 nm than at 800 nm.
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Affiliation(s)
- H Yazawa
- Department of Electronics and Electrical Engineering, Faculty of Science and Technologies, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
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Lozovoy VV, Gunaratne TC, Shane JC, Dantus M. Control of Molecular Fragmentation Using Binary Phase-Shaped Femtosecond Laser Pulses. Chemphyschem 2006; 7:2471-3. [PMID: 17072936 DOI: 10.1002/cphc.200600283] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Vadim V Lozovoy
- Department of Chemistry, Michigan State University, East Lansing MI 4882, USA
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Kong F, Luo Q, Xu H, Sharifi M, Song D, Chin SL. Explosive photodissociation of methane induced by ultrafast intense laser. J Chem Phys 2006; 125:133320. [PMID: 17029473 DOI: 10.1063/1.2204919] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A new type of molecular fragmentation induced by femtosecond intense laser at the intensity of 2 x 10(14) W/cm2 is reported. For the parent molecule of methane, ethylene, n-butane, and 1-butene, fluorescence from H (n = 3-->2), CH (A 2Delta, B 2Sigma-, and C 2Sigma+-->X 2Pi), or C2 (d 3Pi g-->a 3Pi u) is observed in the spectrum. It shows that the fragmentation is a universal property of neutral molecule in the intense laser field. Unlike breaking only one or two chemical bonds in conventional UV photodissociation, the fragmentation caused by the intense laser undergoes vigorous changes, breaking most of the bonds in the molecule, like an explosion. The fragments are neutral species and cannot be produced through Coulomb explosion of multiply charged ion. The laser power dependence of CH (A-->X) emission of methane on a log-log scale has a slope of 10 +/- 1. The fragmentation is thus explained as multiple channel dissociation of the superexcited state of parent molecule, which is created by multiphoton excitation.
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Affiliation(s)
- Fanao Kong
- Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, People's Republic of China.
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Tanaka M, Panja S, Murakami M, Yatsuhashi T, Nakashima N. Intact molecular ion formation of cyclohexane and 2,3-dimethyl-1,3-butadiene by excitation with a short, intense femtosecond laser pulse. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.06.065] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Yazawa H, Tanabe T, Okamoto T, Yamanaka M, Kannari F, Itakura R, Yamanouchi K. Open-loop and closed-loop control of dissociative ionization of ethanol in intense laser fields. J Chem Phys 2006; 124:204314. [PMID: 16774339 DOI: 10.1063/1.2200706] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The relative yield of the C-O bond breaking with respect to the C-C bond breaking in ethanol cation C2H5OH+ is maximized in intense laser fields (10(13)-10(15) Wcm2) by open-loop and closed-loop optimization procedures. In the open-loop optimization, a train of intense laser pulses are synthesized so that the temporal separation between the first and last pulses becomes 800 fs, and the number and width of the pulses within a train are systematically varied. When the duration of 800 fs is filled with laser fields by increasing the number of pulses or by stretching all pulses in a triple pulse train, the relative yield of the C-O bond breaking becomes significantly large. In the closed-loop optimization using a self-learning algorithm, the four dispersion coefficients or the phases of 128 frequency components of an intense laser pulse are adopted as optimized parameters. From these optimization experiments it is revealed that the yield ratio of the C-O bond breaking is maximized as far as the total duration of the intense laser field reaches as long as approximately 1 ps and that the intermittent disappearance of the laser field within a pulse does not affect the relative yields of the bond breaking pathways.
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Affiliation(s)
- Hiroki Yazawa
- Department of Electronics and Electrical Engineering, Faculty of Science and Technologies, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
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Breunig HG, Lauer A, Weitzel KM. Control of Branching Ratios in the Dissociative Ionization of Deuterium Chloride. J Phys Chem A 2006; 110:6395-8. [PMID: 16706393 DOI: 10.1021/jp061890t] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The dissociative ionization of deuterium chloride (DCl) has been investigated by employing femtosecond laser pulses at 805 nm. The product branching ratio D(+)/Cl(+) of the fragments D(+) and Cl(+) is strongly affected by the chirp alpha of the laser pulses. The ratio can be controlled by a factor of 3 ranging from D(+)/Cl(+) = 0.7 at alpha = -800 fs(2) to D(+)/Cl(+) = 1.9 at alpha = +150 fs(2). The observation can be rationalized by a model where negative chirp favors intra-electronic state excitation, and positive chirp favors inter-electronic state excitation in the dissociation of the molecular ion. Complementary experiments on hydrogen chloride (HCl) are discussed.
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Kono H, Sato Y, Kanno M, Nakai K, Kato T. Theoretical Investigations of the Electronic and Nuclear Dynamics of Molecules in Intense Laser Fields: Quantum Mechanical Wave Packet Approaches. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2006. [DOI: 10.1246/bcsj.79.196] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Tanabe T, Kannari F, Korte F, Koch J, Chichkov B. Influence of spatiotemporal coupling induced by an ultrashort laser pulse shaper on a focused beam profile. APPLIED OPTICS 2005; 44:1092-8. [PMID: 15751701 DOI: 10.1364/ao.44.001092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
4f pulse shapers have been widely used to temporally manipulate femtosecond optical pulses by spectral filtering. When the temporal waveform is manipulated with a spatial light modulator consisting of segmented pixels, the spatial profile of the output beam also varies because of diffraction at the pixel array, which is known as a spatiotemporal coupling effect. This effect produces a complicated spatio-temporal profile near the focus of the ultrashort pulses, which may affect the interpretation of experimental results obtained with shaped ultrashort pulses. We investigate the spatial intensity distribution at the focus of temporally shaped pulses through ablation experiments. The three-dimensional space-time beam profile is also numerically calculated.
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Affiliation(s)
- Takasumi Tanabe
- Department of Electronics and Electrical Engineering, Faculty of Science and Technologies, Keio University, Kohoku-ku, Yokohama 223-8522, Japan
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Langhojer F, Cardoza D, Baertschy M, Weinacht T. Gaining mechanistic insight from closed loop learning control: The importance of basis in searching the phase space. J Chem Phys 2005; 122:14102. [PMID: 15638637 DOI: 10.1063/1.1826011] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
This paper discusses different routes to gaining insight from closed loop learning control experiments. We focus on the role of the basis in which pulse shapes are encoded and the algorithmic search is performed. We demonstrate that a physically motivated, nonlinear basis change can reduce the dimensionality of the phase space to one or two degrees of freedom. The dependence of the control goal on the most important degrees of freedom can then be mapped out in detail, leading toward a better understanding of the control mechanism. We discuss simulations and experiments in selective molecular fragmentation using shaped ultrafast laser pulses.
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Affiliation(s)
- Florian Langhojer
- Department of Physics, Stony Brook University, Stony Brook, NY 11794, USA
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Kono H, Sato Y, Tanaka N, Kato T, Nakai K, Koseki S, Fujimura Y. Quantum mechanical study of electronic and nuclear dynamics of molecules in intense laser fields. Chem Phys 2004. [DOI: 10.1016/j.chemphys.2004.04.017] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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36
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Mathur D, Rajgara FA. Dissociative ionization of methane by chirped pulses of intense laser light. J Chem Phys 2004; 120:5616-23. [PMID: 15267438 DOI: 10.1063/1.1649723] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Measurements have been made of optical field-induced ionization and fragmentation of methane molecules at laser intensities in the 10(16) W cm(-2) range using near transform limited pulses of 100 fs duration as well as with chirped pulses whose temporal profiles extend up to 1500 fs. Data is taken both in constant-intensity and constant-energy modes. The temporal profile of the chirped laser pulse is found to affect the morphology of the fragmentation pattern that is measured. Besides, the sign of the chirp also affects the yield of fragments like C2+, H+, and H2+ that originate from methane dications that are formed by optical field-induced double ionization.
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Affiliation(s)
- D Mathur
- Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005, India.
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Ohmura H, Nakanaga T. Quantum control of molecular orientation by two-color laser fields. J Chem Phys 2004; 120:5176-80. [PMID: 15267388 DOI: 10.1063/1.1644102] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We demonstrate molecular orientation by using phase-controlled two-color omega+2omega laser pulses with an intensity of 1.0x10(12) W/cm(2) and a pulse duration of 130 fs. The orientation of three iodine-containing molecules (IBr, CH(3)I, and C(3)H(5)I) was monitored by the directional asymmetries of the photofragment angular distribution in dissociative ionization. In all three molecules, the directional asymmetry showed an oscillating behavior dependent on the relative phase difference between omega and 2omega pulses. The phase dependence of the directional asymmetry observed in iodine ions and counterpart ions were out of phase with each other. This result shows that a phase-controlled omega+2omega optical field discriminates between parallel and antiparallel configurations of aligned molecules that have a permanent dipole. This method performed well because (1) molecular orientation can be achieved by all-optical fields; (2) the direction of orientation is easily switched by changing the sign of the quantum interference; and (3) this method is free from any resonance constraint and thus can be applied to any molecule.
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Affiliation(s)
- Hideki Ohmura
- Photoreaction Control Research Center, National Institute of Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8565, Japan.
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