Coherent VUV generation High order Harmonics in Gases
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Transcript Coherent VUV generation High order Harmonics in Gases
Coherent VUV generation :
High order Harmonics in gases (160 - 10nm)
Rare gas (jet, cell, capillary)
Forward Phase-matching
Laser 5-50fs, 1-30mJ, 10Hz-1kHz
IL ~1014 -1015 Wcm-2
Linear pol.
Spectral selection /focussing
Characterization
Application
Interaction of atoms with high laser field
IL = 1013 -1017 W/cm2
Re-collision
Multiionization
field-electron momentum transfer
Above-threshold Ionization
(ATI)
2- Acceleration
3- Recombination
Ultra-short (as) XUV burst
wUVX = Ec + Ip
Emission time te
ELaser
ELaser
1- Tunnel
ionization
ti
te
time
xelec
Discrete / broadband XUV emission
8
Ne
120
10
2
100
7
80
10
Cutoff
60
65
6
Phase (rad)
Nb photons ~ |Amplitude|
Plateau
25
40
10
20
5
10
0
30
25
20
15
(nm)
Phase of XUV emission dfXUV =
Single harmonic
(Salières et al. Science 2001)
Harmonic phase fq ≈ qfLaser + a IL
Coherence properties
a dIL + te dwXUV
Broadband emission
(Paul et al. Science 2001, Mairesse Science 2003)
Characterization of attosecond pulse train
Attosecond time structure and dynamics
45
EX(t) = S Aq e-iwq(t - teq)
Intensity (arbitrary units)
40
N
35
30
H25-33 (N = 5)
<w25-33>, te
25
H35-43
H45-53
20
<w35-43>, te
15
10
H55-63
H25-63
t =150 as
5
0
0
500
Energy
wUVX
1 000
1 500
Time (as)
2 000
2 500
Electronic trajectory in the laser field
Proof of semi-classical three-step model
Dinu et al., PRL 2003
Mairesse et al, PRL 2004
Energy / Peak power
Hannover: KrF 14mJ 500fs
1GW
Riken 16mJ
10µJ
Energy / pulse
100MW
Ar
µJ
Riken 16mJ
Saclay : EL= 20-25mJ
Riken 130mJ 10MW
100nJ
MW
Ne
10nJ
100kW
Peak Power (20fs XUV pulse)
Xe
nJ
160 120
80
70
60
50
(nm)
40
30
20
10
Scaling laser energy and medium at constant IL (Laserlab I3 ) 10µJ
Spectral selection
• Grating time stretch
Al
• Silica plates + metallic filters
100
Filter Transmission (%)
CXRO data
100nm
160nm
80
Measured T
thickness : 100nm
160nm
60
40
20
90
0
80
70
7
9
11
13
60
15
17
19
21
23
25
27
Harm order
50
40
0,50
30
0,45
20
0,40
7
9
11
13
In, Sn
15
17
19
In 162nm (CXRO)
Sn 162nm
0,35
10
0
7
9
11
13
15
17
19
21
23
25
Harmonic order
• Multilayer mirrors (< 40 nm)
Transmission
Reflectivity of two SiO2 Plates at 10°
RIR ~ 10-4
100
0,30
0,25
0,20
0,15
0,10
0,05
0,00
10
15
20
Photon energy (eV)
25
30
29
Spatial Coherence of High Harmonics
g = 0.5 :
Coherent flux ~ 75% Total flux
Coherent Flux / Total Flux
Collab. Lab. Charles Fabry Orsay
= 61.5 nm (H13)
1,0
0,5
0,0
Fresnel bi-mirror Interferometer
H13 (15)
61nm
0,2
0,4
0,6
0,8
Coherence degree g
d=1mm
d=2mm
d=3mm
Le Déroff et al. PRA 61 (2000) 043802
1,0
Focussing
• Multilayer spherical M
f=200 mm
f=50mm
• Parabola f=70mm
H15 (52 nm)
10
5
2.5 µm
0
6
Spot diameter (µm)
w0 (µm)
15
• Bragg Fresnel lens (Mo/Si)
H37 (21.6 nm)
8
6
4
2
Zeitoun et al. LOA-LIXAM
4
-20
-10
10
M
2
Distance to focus (µm)
2
0
0
200
400
600
800
1000
Backing Pressure (torr)
1µJ at 20eV : IUVX ~ 1014 W.cm-2
20
Mutually coherent harmonic sources
Separated spatially
x=
80µm
180µm
380µm
600µm
x
H17
Spatial interferometry
Separated temporally
1,0
t=450fs
t=150fs
t
Intensity
0,8
H11
0,6
0,4
Spectral interferometry
0,2
0,0
-5
-3
-1
1
(Å)
3
5
-3
-1
1
(Å)
3
5
Temporal properties
XUV Intensity (arb. units)
0,25
/ ~10-3 -10-2
Ar
0,20
25
Coherence time < pulse duration
0,15
0,10
0,05
0,00
50
45
40
35
30
25
(nm)
fq
I L
qwL a
Frequency modulation :
t
t
Complete characterization of an XUV pulse
Principle of SPIDER in the visible
w
2 Replicas
•Temporal delay t
w0
•Spectral shift W
Spectral
interference
t
w0W w0
Grating
S (w) E(w) ² E(w - W) ²
2 E(w) E(w - W) cos(j (w) - j (w - W) wt )
Reconstruction of E(w) and j(w) from the
spectral interference pattern
C. Iaconis & I.A. Walmsley, Optics Letters 23 (1998)
Transposition in XUV : “Dazzling SPIDER”
w0
w0dw
t
Laser
Oscillator
w0
DAZZLER
Lens
Gas
Jet
wqW
t
wq
Amplifier
F. Verluise et al., Optics Letters 25 (2000)
Acousto-optic filter Tailoring of the IR pulse
HH
Generator
Creation of two delayed replicas
t is programmable and accurately set by the Dazzler
Spectral shift of one of them
dw set by cutting the wings of the laser spectrum
HHG
Transfer as W=q.dw on harmonic q
W is measured on the harmonic spectra
Mairesse et al. PRL 2005
SPIDER XUV SPECTRUM
Phase-locked XUV pulses
Intensity
Intensity (a.u.)
w
10
9
25,6 25,7 25,8 25,9 26,0 26,1 26,2
w (.10
-15
rad/s)
Quadratic spectral phase
Quadratic XUV temporal phase (IL-dependent)
Negative linear chirp :
wq = qwL + bq t
8
Phase (rad)
SPIDER
ALGORITHM
11
Temporal profile of harmonic emission
IR
XUV (H11)
FWHM=50fs
FWHM=22fs Consistent
Chirp Rate b11= 1.2 10
236
1
231
230
229
-2
Chirp rate bq (s )
Intensity
232
XUV Phase (rad)
233
x10
Exp. bfund=0
Th.
27 -2
Exp. bfund=0.8 10 s
Th.
0
-1
-2
-3
13
-100
-50
0
50
100
228
s-2
28
235
234
28
15
17
19
Order
21
23
Varju et al., JMO 52, 379 (2005)
Time (fs)
Complete characterization of harmonic pulse
Amplification of harmonics in a laser medium
20 mJ, 30 fs
Delay line
/4
1 J, 30 fs
10Hz
Ph. Zeitoun et al., Nature 431, 426 (2004)
HHG cell
Toroidal Mirror
Kr plasma
Al Filter
3d94d J=0
32,6nm
towards diagnostics
3d94p J=1
Collisions
e - ions
Ni-like Kr 8+ : (Ne)3s23p63d10
Amplification in Krypton IX plasma at 32.8 nm
12000
Amplified harmonic
10000
8000
6000
HHG +XRL
non synchronized
XRL line
4000
2000
0
0
100
200
300
400
500
600
600
700
800
Prints of Laser at 32.8 nm
Harmonic 25 alone
Amplified Harmonic
Amplification Factor : 15 à 200 (depending on seed level)
Divergence : < 2 mrad
Amplification of harmonics in X-Ray laser : TUIXS (NEST)
Broad band Amplification
ASE regime
L’amplification
dépend du >
niveau
d’injection
Gss = 80 cm-1
Iseed ~ Isat/100 : strong amplification (x 200)
Iseed ~ 4Isat : moderate amplification ( x 20)
Researchers - Collaborations - Contracts
Attophysics group 2005
P. Breger
B. Carré
M.-E. Couprie
H. Merdji
P. Monchicourt
P. Salière s
H. Wabnitz
W. Boutu
M. de Grazia
M. Labat
G. Lambert
Y. Mairesse
PDoc
PhD
PhD
PhD
PhD
PhD
Collaborations
Lab. Francis Perrin, CEA-Saclay
Lab. Optique Appliquée, ENSTA-Ecole Polytechnique, Palaiseau
Centre d’Etudes des Lasers Intenses et Applications, Bordeaux
Lab. Interaction du rayonnement X Avec la Matière, Orsay
Lab. Charles Fabry , Institut d’Optique, Orsay
Service de Chimie Moléculaire, CEA-Saclay
Lund Laser Center, Lund
CUSBO, Politecnico Milano
FOM Institute for Atomic and Molecular Physics, Amsterdam
IESL- FORTH, Heraklion, Creete
INOA-LENS, Firenze
Brookhaven Nat Lab
J. J. Thomson Lab., Univ. Reading
Kurchatov Institute, Moscow
Contracts
I3 Laserlab : access (SLIC) / Development of Coherent ultra-short XUV source
Applications of Coherent ultra-short XUV : Marie Curie RTN “XTRA”
Amplification of harmonics in X-Ray laser : TUIXS (NEST)
Seeding of FEL with laser harmonics generated in gas : EUROFEL-DS4
Saclay Laser-matter Interaction Center
UHI10
LUCA
PLFA
Power: 10TW
Duration: 65 fs
Power: <1TW
Power: 0.4TW
reprate: 10 Hz
Duration: 45 fs
Duration: 30 fs
Intensity: >3.1018W/cm2
Reprate: 20 Hz
Reprate: 1 kHz
Plasma physics
+1 line 560-650 nm (GW)
+ 2 NOPAs (~5GW)
Particles acceleration
5 experimental stations
Tunability: 520-750 nm
B4.2 Time-resolved
diagnostics of dense plasmas
XUV interferometer using HH mutual coherence
Collab. Lab. Ch. Fabry Orsay
Magnif. ~10
Pump
Imaging elliptical mirror
B4C/Si multilayer (32nm)
plasma
Object
Resolution (object): 4 µm
Field diam ~ 0.8 mm.
IR beam
splitter
Salières et al. PRL (1999)
Descamps et al. Optics Lett. (2000)
Interferogram
in virtual
Object plane
Applications of Coherent XUV pulses
High intensity in the XUV (~ 1012W/cm2) : Non Linear processes
Short duration (10fs100as) /synchronization with laser : time-resolved studies
Intrinsic or mutual coherence : interferometry techniques
Atomic physics (photoionization): Toma et al. Phys. Rev. A (2000).
Solid state physics : Quéré et al., Phys. Rev. B (2000), Gaudin et al., Appl. Phys. B (2004)
Plasma physics : Salières et al., Phys. Rev. Lett. (1999), Descamps et al., Opt. Lett. (2000).
In 2001-2005
Multi-photon/multi-color photoionization of atoms (AMOLF 2003)
Photoionization of water in the liquid phase (Univ. Stockholm 2004)
Surface ablation by XUV pulses (Univ. Warsaw, PALS 2005)
Photoionization of clusters by XUV pulses (Technische Univ. Berlin
2005)
Spectral selection
• Grating time stretch
• Silica plates + metallic filters
Filter Transmission (%)
100
100
90
Tr / Re (%)
80
70
Transmission
Reflectivity
60
50
Polarization S
40
30
CXRO data
100nm
160nm
80
Measured T
thickness : 100nm
160nm
60
40
20
20
0
10
0
5
10
15
20
7
25
9
11
13
15
17
19
21
23
Harm order
100
7
0,50
90
9
11
13
0,45
80
0,40
70
0,35
Transmission
Reflectivity of two SiO2 Plates at 10°
Incidence (°)
60
50
40
30
17
19
In 162nm (CXRO)
Sn 162nm
0,30
0,25
0,20
0,15
20
0,10
10
0,05
0
15
0,00
7
9
11
13
15
17
19
Harmonic order
21
23
25
10
15
20
Photon energy (eV)
25
30
25
27
29
Spectral selection and focussing
• Multilayer mirror (< 40 nm)
Parabola f=70mm
0,35
0,30
Spherical Mirror
f=200 mm
Simul (inc=4°)
Exp:
,
incidence 4°, 5°
B4C/Si
15
0,20
2.5 µm
0,15
0,10
w0 (µm)
Reflectivity
0,25
Zeitoun et al. LOA-LIXAM
0,05
30
35
40
Wavelength (nm)
5
2
4
M
1µJ at 20eV : IUVX ~ 1014 W.cm-2
10
0
6
0,00
25
H15 (52 nm)
2
0
200
400
600
800
Backing Pressure (torr)
• Bragg Fresnel lens (Mo/Si)
1000
Complete characterization of XUV pulse : SPIDER
w
2 Replicas Principle of IR SPIDER
Spectral
interference
•Temporal delay t
w0
•Spectral shift W
t
w1W w1
Grating
S (w) E(w) ²
E (w - W) ²
2 E(w) E(w - W) cos(j (w) - j (w - W) wt )
Reconstruction of j(w) from the
spectral interference pattern
C. Iaconis & I.A. Walmsley, Optics Letters 23 (1998)