Coherent electron scattering captured by an attosecond quantum stroboscope.

We demonstrate a quantum stroboscope based on a sequence of identical attosecond pulses that are used to release electrons into a strong infrared (IR) laser field exactly once per laser cycle. The resulting electron momentum distributions are recorded as a function of time delay between the IR laser and the attosecond pulse train using a velocity map imaging spectrometer. Because our train of attosecond pulses creates a train of identical electron wave packets, a single ionization event can be studied stroboscopically. This technique has enabled us to image the coherent electron scattering that takes place when the IR field is sufficiently strong to reverse the initial direction of the electron motion causing it to rescatter from its parent ion.

[1]  J. Spence,et al.  Diffractive electron imaging of nanoparticles on a substrate , 2005, Nature materials.

[2]  M. Vrakking.  An iterative procedure for the inversion of two-dimensional ion/photoelectron imaging experiments , 2001 .

[3]  J. Mauritsson,et al.  Attosecond pulse trains generated using two color laser fields , 2006 .

[4]  J. Levesque,et al.  Tomographic imaging of molecular orbitals , 2004, Nature.

[5]  P. Balcou,et al.  Observation of a Train of Attosecond Pulses from High Harmonic Generation , 2001, Science.

[6]  Direct XUV probing of attosecond electron recollision. , 2007, Physical review letters.

[7]  Gallagher Tf,et al.  Above-threshold ionization in low-frequency limit. , 1988 .

[8]  Yang,et al.  Above threshold ionization beyond the high harmonic cutoff. , 1993, Physical review letters.

[9]  P. Johnsson,et al.  Attosecond electron wave packet interferometry , 2006 .

[10]  P. Corkum,et al.  Attosecond and angstrom science , 2007 .

[11]  T. Kanai,et al.  Quantum interference during high-order harmonic generation from aligned molecules , 2005, Nature.

[12]  P. Corkum,et al.  LETTER TO THE EDITOR: Reading diffraction images in strong field ionization of diatomic molecules , 2004 .

[13]  J. Miao,et al.  Extending the methodology of X-ray crystallography to allow imaging of micrometre-sized non-crystalline specimens , 1999, Nature.

[14]  E. Goulielmakis,et al.  Direct Measurement of Light Waves , 2004, Science.

[15]  U. Heinzmann,et al.  Time-resolved atomic inner-shell spectroscopy , 2002, Nature.

[16]  Schafer,et al.  High-order harmonic generation from atoms and ions in the high intensity regime. , 1992, Physical review letters.

[17]  P. Corkum,et al.  Plasma perspective on strong field multiphoton ionization. , 1993, Physical review letters.

[18]  U. Heinzmann,et al.  Attosecond metrology , 2007, Nature.

[19]  L. Poletto,et al.  Isolated Single-Cycle Attosecond Pulses , 2006, Science.

[20]  W. H. Benner,et al.  Femtosecond diffractive imaging with a soft-X-ray free-electron laser , 2006, physics/0610044.

[21]  P. Agostini,et al.  The physics of attosecond light pulses , 2004 .

[22]  Anders Persson,et al.  Amplitude and phase control of attosecond light pulses. , 2005, Physical review letters.

[23]  P. Corkum,et al.  Attosecond streak camera. , 2002, Physical review letters.

[24]  P. Balcou,et al.  Attosecond electron wave packet dynamics in strong laser fields. , 2005, Physical review letters.

[25]  F. Légaré,et al.  Sub-laser-cycle electron pulses for probing molecular dynamics , 2002, Nature.

[26]  P. Balcou,et al.  Broadband Attosecond Pulse Shaping , 2007, 2007 Conference on Lasers and Electro-Optics (CLEO).

[27]  U. Kleineberg,et al.  Atomic transient recorder , 2004, Nature.

[28]  U. Kleineberg,et al.  Steering Attosecond Electron Wave Packets with Light , 2002, Science.

[29]  L. Poletto,et al.  Controlling attosecond electron dynamics by phase-stabilized polarization gating , 2006 .

[30]  David H. Parker,et al.  Velocity map imaging of ions and electrons using electrostatic lenses: Application in photoelectron and photofragment ion imaging of molecular oxygen , 1997 .

[31]  N. Kabachnik,et al.  Theoretical description of atomic photoionization by an attosecond XUV pulse in a strong laser field: effects of rescattering and orbital polarization , 2007 .