2. 1. Ionization of molecules - ( MO-ADK theory)
Scope
1. Ionization of molecules - ( MO-ADK theory)
Alignment dependence – imaging MO’s (KSU data)
(Experiments: double ionization; high-harmonic generation)
“Molecular clock”: Time is read from the kinetic energy release of the fragments with sub-fs accuracy
Attosecond XUV + IR laser physics
how to extract lifetime of autoionizing states
Stark effect of laser-assisted photoexcitations
Probing electron dynamics in the time domain
3. Summary

3. APT-attosecond pulse train issues
130 as from the plateau region– the harmonics must be phase locked
two sources of asynchronism:
1.short and long paths, thus two bursts– select short by phase matching condition by focusing before the gas jet and a diaphram after
2.different harmonics, due to different recombination times, linear chirp, limits the as pulse durations to about 100as, need chirp compensation
Relative phases measured by two-photon, two color ionizations—sideband analysis--RABITT
other works– trying to relate the harmonics to electron dynamics
HHG facts: plateau region has positive chirp for the short trajectory
phase locked in the cutoff region

4. z: off the focus
presented by the Saclay group see Mairesse et al PRL 93, (04); also Science 302, 1540 (03)

5. The Milano group also made such studies using short pulses with CEP stabilized

6. not cep sensitive
from simulation, PRL92,113904(04)

7. apt with 170as at Lund --simulation

8. From RABITT
amplitude shaping
phase shaping
APT pulses

9. selecting the time of ionization by apt
APT+IR
good HHG
sharp harmonics
selecting the time of ionization by apt
schaffer et al PRL92, (04)
preliminary data from U. Keller’s group confirm the HHG enhancement
Lund’s group measured the ATI enhancement to higher electron energies

10. HHG as light sources
Crete’ group, use 7th and 13th harmonics for cross correlation experiments

11. Attosecond electron bursts for imaging –”industry?”
Corkum-
Paulus– use the phase information in the tunneling electrons for interference?
M. Lezius-
Ivanov– theory for imaging by electrons (quite complicated, but not impossible)
Villeneuve– imaging thru HHG (N2 Nature04)
Kietzer-ALLE
need to know e-wave packet better.

12. Krausz’s recent work tried IR-pump/XUV probe– signal too weak
XUV pump/IR probe
look at the time of shakeup electrons, rise time is about 4fs

13. The COLTRIMS people
Doerner- e-e spectra, sequential, nonsequential, also circularly polarized, laser lab soon
Moshammer– double and multiple ionization
cold recoil ions
Helm- negative ions, atoms
All good talks– theory done by experimentalists mostly,
S-matrix theory does not really work

14. HHG of molecules Marangnos+Italy group
alignment dependence, short and long pulses; difference in H2 and D2

16. Activities--
Colloquium at Univ. of Electrocommunications
Seminar at RIKEN
1st talk at the conference (more mixed audience)
covered:
alignment-depn ionization rates and imaging of the electron cloud
molecular cloud
laser-assisted autoionization

17. Intense XUV and soft X-ray source
0.33  = 29.6 nm
(Ti:Sapphire H27)
Above-threshold ionization (ATI) of He
Sekikawa et al., Nature 432, 605 (2004)
h = 27.9 eV
ATI & Two-photon double ionization (TPDI) of He
Hasegawa et al., Phys. Rev. A, in press; Nabekawa et al., Phys. Rev. Lett., in press
h = 41.8 eV
focused to an area of 10mm2 by a mirror
Assuming the pulse duration < 30 fs
XUV
1014 W/cm2
Soft X-ray
Mashiko et al., Opt. Lett. 29, 1927 (2004)

18. High-order harmonic generation (HHG)
RIKEN, Laser Technology Laboratory (K. Midorikawa)
25  = 13.5 nm (Ti:S H59)
0.33 J @  = 29.6 nm (Ti:S H27)
1 J @  = 54 nm (Ti:S H15)
4.7 J @  = 62.3 nm (Ti:S H13)
7 J @  = 72.7 nm (Ti:S H11)
CEA-Saclay, DSM/DRECAM/SPAM (P. Salieres)
1.9 J @  = 53.3 nm (Ti:S H15)
University of Tokyo, ISSP (S. Watanabe)
1.2 J @  = 49.7 nm (KrF Excimer H5)
Takahashi et al.
Phys. Rev. A 66, (2002)
Opt. Lett. 27, 1920(2002)
JOSA B 20, 158 (2003)
Appl. Phys. Lett. 84, 4 (2004)
Hergott et al.
Phys. Rev. A 66, (2002)
Yoshitomi et al.
Opt, Lett. 27, 2170 (2002)