Laser-assisted electron diffraction for femtosecond molecular imaging.

We report the observation of laser-assisted electron diffraction (LAED) through the collision of 1 keV electrons with gas-phase CCl4 molecules in a femtosecond near-infrared laser field. In the angular distribution of the scattered electrons with the energy shifts of ±ℏω, we observed clear diffraction patterns which reflect the geometrical structure of the molecules at the moment of laser irradiation. Our results demonstrate that ultrafast nuclear dynamics of molecules can be probed by LAED with the high temporal (<10 fs) and spatial (∼0.01 Å) resolutions.

[1]  Matthias Golling,et al.  Cutting-Edge High-Power Ultrafast Thin Disk Oscillators , 2013 .

[2]  Milo M. Lin,et al.  Photon-induced near-field electron microscopy (PINEM): theoretical and experimental , 2010 .

[3]  Aleksander Jablonski,et al.  ELSEPA - Dirac partial-wave calculation of elastic scattering of electrons and positrons by atoms, positive ions and molecules , 2005, Comput. Phys. Commun..

[4]  A. Zewail,et al.  Photon-induced near field electron microscopy , 2013, Optics & Photonics - Optical Engineering + Applications.

[5]  Y. Morimoto,et al.  Apparatus for laser-assisted electron scattering in femtosecond intense laser fields. , 2011, The Review of scientific instruments.

[6]  J. Kamiński,et al.  ELECTRON-ATOM COLLISIONS IN A LASER FIELD , 1998 .

[7]  A. Zewail,et al.  Ultrafast electron diffraction. Velocity mismatch and temporal resolution in crossed-beam experiments , 1993 .

[8]  Ferenc Krausz,et al.  Time-resolved electron diffraction from selectively aligned molecules. , 2009, Physical review letters.

[9]  Francesc Salvat,et al.  Optical-model potential for electron and positron elastic scattering by atoms , 2003 .

[10]  N. J. Mason.  Laser-assisted electron-atom collisions , 1989 .

[11]  H. Daimon,et al.  Measurement of Differential Cross Sections of Low-Energy Electrons Elastically Scattered by Gas Molecules. III. Effect of Intramolecular Double Scattering as Observed in the Scattering of 70–400 eV Electrons by Carbon Tetrachloride , 1983 .

[12]  N. Kroll,et al.  Charged-Particle Scattering in the Presence of a Strong Electromagnetic Wave , 1973 .

[13]  Cesar Jauregui,et al.  High-power fibre lasers , 2013 .

[14]  Ahmed H. Zewail,et al.  4D Visualization of Transitional Structures in Phase Transformations by Electron Diffraction , 2007, Science.

[15]  M. Kimura,et al.  A Reinvestigation of Small-angle Electron Scattering by CS2 and CCl4 Molecules , 1982 .

[16]  A. Zewail,et al.  Enhancing image contrast and slicing electron pulses in 4D near field electron microscopy , 2012 .

[17]  A. Zewail,et al.  Structural preablation dynamics of graphite observed by ultrafast electron crystallography. , 2008, Physical review letters.

[18]  R. Miller,et al.  Electronic acceleration of atomic motions and disordering in bismuth , 2009, Nature.

[19]  T. Ohshima,et al.  Alignment of CS2 in intense nanosecond laser fields probed by pulsed gas electron diffraction , 2003 .

[20]  Y. Morimoto,et al.  Observation of laser-assisted electron-atom scattering in femtosecond intense laser fields. , 2010, Physical review letters.

[21]  Peter M. Weber,et al.  Ultrafast Diffraction Imaging of the Electrocyclic Ring-Opening Reaction of 1,3-Cyclohexadiene , 2001 .

[22]  S. A. Aseyev,et al.  Ultrafast Electron Microscopy for Chemistry, Biology and Material Science , 2013 .

[23]  A. Zewail,et al.  Breaking resolution limits in ultrafast electron diffraction and microscopy , 2006, Proceedings of the National Academy of Sciences.

[24]  Terry A. Miller,et al.  Information for : Imaging ultrafast molecular dynamics with laser-induced electron diffraction , 2012 .

[25]  Katsumi Midorikawa,et al.  High-Pulse-Energy Yb:YAG Thin Disk Mode-Locked Oscillator for Intra-Cavity High Harmonic Generation , 2013 .

[26]  Germán Sciaini,et al.  Femtosecond electron diffraction: heralding the era of atomically resolved dynamics , 2011 .

[27]  Martin Centurion,et al.  Imaging of isolated molecules with ultrafast electron pulses. , 2012, Physical review letters.

[28]  Y. Morino,et al.  Mean Square Amplitudes and Force Constants of Tetrahedral Molecules. I. Carbon Tetrachloride and Germanium Tetrachloride , 1960 .

[29]  Tetsuya Ishikawa,et al.  Compact XFEL and AMO sciences: SACLA and SCSS , 2013 .

[30]  H Ihee,et al.  Direct imaging of transient molecular structures with ultrafast diffraction. , 2001, Science.

[31]  M. Fink,et al.  Differential cross sections for elastic electron scattering. III. The C2H2, C2H4, and C2H6 results , 1975 .

[32]  Vladimir A. Lobastov,et al.  Ultrafast electron diffraction (UED) a new development for the 4D determination of transient molecular structures , 2003 .

[33]  Natalie M. Cann,et al.  Absolute scale determination for photoabsorption spectra and the calculation of molecular properties using dipole sum-rules , 1997 .

[34]  Fabrizio Carbone,et al.  A perspective on novel sources of ultrashort electron and X-ray pulses , 2012 .

[35]  Jerome B. Hastings,et al.  Ultrafast Time-Resolved Electron Diffraction with Megavolt Electron Beams , 2006 .

[36]  H. C. Bandulet,et al.  Laser-Induced Electron Tunneling and Diffraction , 2008, Science.

[37]  Jeffrey K. Nagle,et al.  Atomic polarizability and electronegativity , 1990 .