Transcript Atoms in strong laser fields

Generation and Application of
Attosecond pulse trains
Anne L’Huillier
Femtosecond laser pulse
Attosecond pulse train
Generation
• Easier, more signal
• Complementary tool
• Possibility of control
Application
Controlled
sequences of
attosecond pulses
Measure and
control electron
dynamics
Controlled sequences of attosecond pulses
Femtosecond laser pulse
Attosecond pulse train
~1014 W cm-2
•Pulse separation
•Central photon energy
•Number of pulses
•Pulse duration (metallic filter- Mansten et al. OL 2007)
Attosecond pulse trains using a two-color field
2.7 fs
E-field (a. u.)
1.3 fs
Time
(as)
Time
(as)
Temporal measurements
Odd harmonics
Even and odd harmonics
Inensity (a. u.)
Spectral measurements
Attosecond pulse trains using a two-color field
Energy (eV)
Energy (eV)
Streaking
Trace
1 cycle
1 cycle
Delay
Delay
Mauritsson et al., PRL 2006
Kinetic energy
3 Up
Kinetic energy
Attosecond pulse trains using a two-color field
Energy (eV)
36
0
0.5
1
Return time (T)
28
0
20
0.5
1
Return time (T)
0
Intensity
Intensity (a. u.)
Energy
(eV)
Energy(eV)
36
28
1
ϕ (p
rad)
Relative
Relative
phase
phase
(π rad)
(π rad)
2
0
2
0
1
0
20
20
0
1
ϕ (p rad)
1
ϕMansten
(p rad)
28
Energy (eV)
Energy
(eV)
36
2
et al., NJP, 2008
2
Intensity (arb. u.)
Central energy of attosecond pulse trains
170 as
Argon +
Aluminum
López-Martens, PRL, 2005
Sansone, Science 2006
Intensity (arb. u.)
0
20
40
60
80
Photon Energy (eV)
100
130 as
Neon +
Zirconium
20
Intensity (arb. u.)
0
40
60
80
Photon Energy (eV)
Gustafsson , Opt. Lett., 2007
100
370 as
Johnsson, PRL, 2007
Xenon +
Aluminum
0
20
40
60
80
Photon Energy (eV)
100
Short attosecond pulse trains
Short driving field
ETH Zurich
•12 fs
•CEO stabilized
Attosecond pulse train
Short attosecond pulse trains
Short attosecond pulse trains : Multiple pulse interferences
Energy
Intensity
Intensity
Intensity
Intensity
Time
N sec. max  N pulses  2
Short attosecond pulse trains : Multiple pulse interferences
N sec. max  N pulses  2
Short attosecond pulse trains : Multiple pulse interferences
CEO- dependence
Intensity (a. u.)
1
0
25
35
Energy (eV)
45
Pfeifer et al. OE 2006
Sansone et al., 2004
Controlled sequences of attosecond pulses
Femtosecond laser pulse
Attosecond pulse train
•Pulse separation
•Number of pulses, down to one
•Central photon energy
•Pulse duration (metallic filter)
Measurement and control of electron dynamics
Attosecond pulse train
synchronized with infrared field
toroidal
mirror
electron
detection
recombination
mirror
1 kHz pulsed
valve
focusing
mirror
4 mJ, 35 fs
800 nm
Ti:Saph
filter
wheel
beamsplitter
delay
stage
Streaking with an attosecond pulse train (1 pulse / cycle)
Ar
Itatani et al., PRL 2002
Mairesse, Quéré, PRA 2005
Kienberger, Science 2002
Sansone, Science 2006
o Higher signal- Coherent superposition
Imaging
o Simulates an electron wave packet moving in a
laser field
o Quantum stroboscope
Coherent electron scattering with a train of attosecond
wave packets
He strong field
130 as
Rescattering of the
electron by the atomic
potential
Corkum, Ivanov et al.
Diffraction by returning wp
Mauritsson et al.,
PRL 2008
Characterization of attosecond pulses in a train
5 10
1012 W/cm2
0
Paul et al. Science 2001
RABITT technique
-10 -5
Delay (fs)
Weak field
q+2
17
19
21
23
25
q
Harmonic Order
The sideband signal oscillates as
2  q2  q  
at
q2

at
q
Ar
small
Characterization of attosecond pulses
Kinetic energy
3 Up
0
The sideband signal oscillates as
2  q2  q  
at
q2

small
at
q
0.5
1
Return time (T)
Mairesse et al.
Science 2003
López-Martens et
al., PRL 2005
Characterization of continuum wave packet
812 nm
796 nm
3p
The sideband signal oscillates as
2  q2  q  atq2  atq
Hässler et al., 2009
( )
He
Characterization of continuum wave packet
3x1012
1010
3p
The sideband signal oscillates as
2  q2  q  atq2  atq
He
(I )
AC- Stark shift of the 3p state
Clock
3p
Probe
Generation and Application of
Attosecond pulse trains
Femtosecond laser pulse
Attosecond pulse train
Generation
• Easier, more signal
• Complementary tool
• Possibility of control
Application
Controlled
sequences of
attosecond pulses
Measure and
control electron
dynamics
Johan Mauritsson
Per Johnsson
Mathieu Gisselbrecht
Erik Mansten
Marko Swoboda
Thomas Fordell
Kathrin Klünder
Marcus Dahlström
ETH, Zurich:
Ursula Keller
FOM, Amsterdam:
Marc Vrakking
Polytechnico Milan:
Mauro Nisoli
LSU:
Kenneth J. Schafer
Mette B Gaarde
Attosecond control of ionization
He
Johnsson, PRL, 2007
Rivière, NJP, 2009