UDIM09, Ischia island, Naples, Italy 1 Valer Tosa National Institute R&D Isotopic Molecular Technologies, Cluj-Napoca, Romania Macroscopic Effects in Single.
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UDIM09, Ischia island, Naples, Italy
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Valer TosaValer TosaNational Institute R&D Isotopic Molecular Technologies, Cluj-Napoca, RomaniaNational Institute R&D Isotopic Molecular Technologies, Cluj-Napoca, Romania
Macroscopic Effects in Single Macroscopic Effects in Single Attosecond Pulse GenerationAttosecond Pulse Generation
Carlo Altucci, Raffaele VelottaCarlo Altucci, Raffaele VelottaDipartimento di Scienze Fisiche, Università “Federico II”, Napoli, ItalyDipartimento di Scienze Fisiche, Università “Federico II”, Napoli, Italy
UDIM09, Ischia island, Naples, Italy
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UDIM09, Ischia island, Naples, Italy
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Layout
1. Tools for numerical modeling of SAP
2. A proposed sheme to obtain a single attosecond pulse (SAP)
3. The mechanism of SAP formation
4. Analysis of scheme feasibility
5. Conclusions
UDIM09, Ischia island, Naples, Italy
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),,()1(),,(1),,(
,2
2
2
2,
2
2,2 tzrE
ct
tzrE
ctzrE
yxeffyx
yx
2
2
020 2
),,,(),,()()(),,,,(
tzrn
tzrInntzrnn epaeaeff
A
'
*
2/3
')"(exp)'()'(),'()],',(exp[
)(),'(2/)'(
'Re2)(
t
ststst
t
st
dttwtEtAttpdttpiS
tAttpdtti
dtitnld
B
2,
2
02,
2
2
2
,2 ),,(),,(
),,(t
tzrP
t
tzrE
ctzrE yx
hyxh
yx
C
Tools
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Scheme of Principle
BS
MG
M
HWP
INPUT
OUTPUT
PA
yddp
dyy
xp
xx
CEPzrTttInL
TtTt
EzrtE
CEPzrtt
EzrtE
,)(2
sin39.1exp,,
,sin39.1exp,,
20
2
0
0
2
0
[for details see C. Altucci et al, Opt. Lett. 33, 2943 (2008) ]
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1D mechanism of SAP formation (1)
-8 -6 -4 -2 0 2
0
1
-8 -6 -4 -2 0 2-8 -6 -4 -2 0 2
0
2
4
6
Time (optical cycles)
Ix, I
y
electron fraction
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1D mechanism of SAP formation
-3.5 -3.0 -2.5 -2.00
2
4
6
8
10
t/T0
single dipole response
-3.5 -3.0 -2.5 -2.00
2
4
6
8
10 single dipole during propagation
t/T0
z=0.0 mm z=0.5 mm z=1.0 mm
-3.5 -3.0 -2.5 -2.00
1
2
3
4
Time (optical cycles)
Final harmonic fieldon-axis
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1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0-40
-20
0
20
40
60
80
Tra
ject
ory
ph
ase
(ra
dia
ns)
z (mm)
tr=-2.6T
0
tr=-3.1T
0
Trajectory analysis (on-axis)
Trajectoryphase:
V. Tosa et al.PRA 79, 043828 (2009)
1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0
-3.1
-3.0
-2.9
-2.8
-2.7
Tim
e (
op
tica
l cyc
les)
z (mm)
short trajectories long trajectories
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-4.0 -3.5 -3.0 -2.5 3.0 3.5 4.0 4.5 5.00
1
2
3
4
5
Time (optical cycles)
Emitted near field
3D SAP formation
-5 -4 -3 -2 -1 0 1 2 3 4 5
10
20
30
40
Time (optical cycles)R
ad
ial co
ord
ina
te
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SAP selection
-4 -3 3 4 5
1
2
3
4
5
6
Inte
nsi
ty (
arb
. u
n.)
Time (optical cycles)
nearfield farfield (iris 1.5 mm @ 500 mm)
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-3.0 -2.5 -2.0 -1.50
2
4
6
In
tens
ity (
arb.
un.
)
Time (o. c.)
15 fs CEP=-/4 CEP=0 CEP=/4
-4.0 -3.5 -3.0 -2.5 -2.00
2
4
6
Inte
nsity
(ar
b. u
n.)
Time (o. c.)
20 fs CEP=0 CEP=2/5 CEP=3/4
-5.0 -4.5 -4.0 -3.5 -3.00
2
4
6
Inte
nsity
(ar
b. u
n.)
Time (o. c.)
25 fs CEP=2/3 CEP=0.7 CEP=3/4
21 31 41
104
105
Po
we
r S
pe
ctru
m
CEP=0 CEP=0.40 CEP=0.75
Explore the limits of the method
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Explore the limits of the method (2)
-4 -3 -2 3 40
1
2
3
4
5
6
7
Time (optical cycles)
0.7 I0
I0
1.3 I0
Intensity variation
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Explore the limits of the method (4)
-4 -2 0 2 40
2
4
6
8
10
12
Time (optical cycles)
constant chirp along radial direction
-5 0 50
2
4
6
8
10
12
Time (optical cycles)
5% radial variation of chirp(but not optimized in CEP)
-4 -2 0 2 4
0
2
4
6
8
10
12
10% radial variation of chirp(but not optimized in CEP)
Time (optical cycles)
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Explore the limits of the method (3)
-4 -3 -2 3 4 5
0
3
6
9
12
15
Ne
ar
field
po
we
r e
mis
sion
Time (optical cycles)
CEP = 0.5 CEP = 0.4 CEP = 0.35
Using a truncated gaussian
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Method efficiency
Case calculated using the polarization gate and conditions specified in
L. J. Sola, et al. Nat. Phys. 2, 319 (2006)
-4 -2 0 20
2
4
6
8
10
12
Har
mon
ic e
mis
sion
Time (optical cycles)
x 6
367 as 352 as
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Conclusions
• Polarization gate does not always insure a SAP at single dipole level
• High brightness SAP can be generated if the interplay among polarization, ionization, and spatial filtering is properly applied
• The proposed scheme could produce single attosecond pulse from multicycle lasers
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