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
w0W 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
w0dw
t
Laser
Oscillator
w0
DAZZLER
Lens
Gas
Jet
wqW
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 (10fs100as) /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
w1W 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)