1 Journées Scientifiques de lEDOM March 8, 2011 10 fs laser chain based on optical parametric...
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Transcript of 1 Journées Scientifiques de lEDOM March 8, 2011 10 fs laser chain based on optical parametric...
1Journées Scientifiques de l’EDOM March 8, 2011
10 fs laser chain based on optical 10 fs laser chain based on optical parametric chirped pulse amplificationparametric chirped pulse amplification
Lourdes Patricia RamirezEquipe Lasers Solides et Applications
Laboratoire Charles Fabry de l’Institut d’Optique (LCFIO), Palaiseau, France
Frédéric DruonDirecteur de thèse
2Journées Scientifiques de l’EDOM March 8, 2011
OutlineOutline
• Motivation: Front end of the Apollon laser• Optical parametric chirped pulse amplification (OPCPA)• Seed source for OPCPA
- Ultrashort approach- Direct XPW approach
• Summary and future work
3Journées Scientifiques de l’EDOM March 8, 2011
Front end of the Apollon 10 PW laser Front end of the Apollon 10 PW laser
High contrast, CEP stable, sub-10 fs, >100 µJ, 1 kHz
Ultrashort seed source @ 800 nm
HEC-DPSSL pumpedhigh rep-rate amplifiers
(Yb:KGW, YAG, CaF2)2 J @ 1030 nm, 10-100 Hz
SHG: ps-ns1 J @ 515 nm
10-100 Hz
Pump source @ 515 nm
NOPCPA(BBO or LBO)
Optical synchronization
Noncollinear Optical Parametric Chirped Pulse
Amplification stages
<10 fs, 100 mJ, @800 nm, 10-100 Hz
10 TW!
Applications: high harmonic generation, attosecond physics, particle acceleration, plasma physics, high energy physics experiments
4Journées Scientifiques de l’EDOM March 8, 2011
Optical parametric amplification (OPA)Optical parametric amplification (OPA)
• Extremely broad amplification bandwidth
• High gain per single pass• High quantum efficiency• Low thermal effects• Reduced amplified
spontaneous emission – high energy and intensity contrast ratio pulses
• Scalability to high energies
Nonlinear CrystalX(2)
p s i
Nonlinear CrystalX(2)
pump
pump
signal
residual pump
amplified signal
idler
signal
idler
Generation
Amplification
5Journées Scientifiques de l’EDOM March 8, 2011
Chirped pulse amplification (CPA)Chirped pulse amplification (CPA)
6Journées Scientifiques de l’EDOM March 8, 2011
OPA + CPA = OPCPAOPA + CPA = OPCPA
Replace with nonlinear crystals e.g. BBO, LBO, KDP
7Journées Scientifiques de l’EDOM March 8, 2011
Front end of the Apollon 10 PW laser Front end of the Apollon 10 PW laser
High contrast, CEP stable, sub-10 fs, >100 µJ, 1 kHz
Ultrashort seed source @ 800 nm
HEC-DPSSL pumpedhigh rep-rate amplifiers
(Yb:KGW, YAG, CaF2)2 J @ 1030 nm, 10-100 Hz
SHG: ps-ns1 J @ 515 nm
10-100 Hz
Pump source @ 515 nm
NOPCPA(BBO or LBO)
Optical synchronization
Noncollinear Optical Parametric Chirped Pulse
Amplification stages
<10 fs, 100 mJ, @800 nm, 10-100 Hz
10 TW!
8Journées Scientifiques de l’EDOM March 8, 2011
Ultrashort seed sourceUltrashort seed source
• Sub-10 fs , >100 µJ, 1 kHz, CEP stable, high contrast ratio at 800 nm • 2 approaches:
Commercial ultrashort Ti:Sa system25 fs, 1.5 mJ, 1 kHz, CEP stable, CR ~ 108
Ultrashort approach: 5 fsHollow core fiber (HCF) pulse compression
Cross polarized wave generation (XPW)5 fs, 100 µJ, CEP preserving, CR ~ 1010
Main disadvantages: low efficiency- Compression in between two stages
Direct XPW: Sub-10 fs approachSpectral broadening and contrast enhancement
via cross polarized wave generation only< 10 fs, 200-300 µJ, CEP preserving, CR ~ 1010
Advantages: higher efficiency- Single stage for broadening and contrast
enhancement- Simple and compact setup
9Journées Scientifiques de l’EDOM March 8, 2011
Ultrashort approach: hollow fiber compressionUltrashort approach: hollow fiber compression
Pulse compression:25 fs to 4.4 fs
Spectral broadening in the HCF:60 nm to 250 nm
500 600 700 800 900 1000
0.0
0.2
0.4
0.6
0.8
1.0
Inte
nsity
(a.
u.)
Wavelength (nm)
HCF 250µm diam, 1m long, 1.3bar Ne: ----E
in=1.3 mJ (~48nm)
----Eout
=0.8mJ (~250nm)
250 nm
>750 µJ
1.4mJ, 25fs>850 µJ
60nm
-30 -20 -10 0 10 20 30
0.0
0.2
0.4
0.6
0.8
1.0
Time (fs)
Inte
nsity
(a.
u.)
10
15
20
25
Pha
se (
rad)
Laser HCF
10Journées Scientifiques de l’EDOM March 8, 2011
Cross polarized wave generation (XPW)Cross polarized wave generation (XPW)
XPW is based on a degenerated four-wave mixing process governed by the anisotropy of the real part of a crystal’s third-order nonlinearity tensor.
Glan 1 Glan 2BaF2
χ(3)
Main features:- Contrast enhancement: depends on the polarizer exctinction ratio (105)- Temporal pulse shortening:- Spectral cleaning and broadening
3t3
3( ) ( )XPW LI t I t
11Journées Scientifiques de l’EDOM March 8, 2011
Ultrashort approach: HCF + XPWUltrashort approach: HCF + XPW
Energy/Spectrum FROG3ω/f-2f
~80 μJ, 5fs
~550μJ, 5fs
~100μJ
Spectral cleaning with XPW:250 nm to 200 nm
XPWHCF
-30 -20 -10 0 10 20 30
0.0
0.2
0.4
0.6
0.8
1.0
Time (fs)
Inte
nsity
(a.
u.)
0
10
20
30
40
50
60
Pha
se (
rad)
Main result: HCF + XPW5 fs, 100 μJ
Compression: 5 fs
12Journées Scientifiques de l’EDOM March 8, 2011
Direct XPWDirect XPW
2.5-mm BaF2
f = 1.5 m
20-cm hollow core waveguide
Polarizer
XPW
25-41 cm
Spatial profile of
XPW beam
Filtered spatial profile of laser
beam
Actual spatial profile of laser
beam
ff1.5 mJ25 fs
Spectral broadening with XPW:60 nm to 140 nm
Pulse compression with XPW:25 fs to 9.6 fs
Main result: Direct XPW
9.6 fs, 300 μJ!
300 μJ
13Journées Scientifiques de l’EDOM March 8, 2011
Summary and future workSummary and future work
• Implemented two seed sources for an OPCPA based laser chain.- Hollow core fiber compression and cross polarized wave generation: 5 fs, 100 µJ, 10-10 contrast ratio- Direct cross polarized wave generation: 9.6 fs, 300 µJ, 10-
10 contrast ratio• Improving the stability and reliability of the direct XPW seed
source• Developing a stretcher for the seed source• Perform OPCPA
14Journées Scientifiques de l’EDOM March 8, 2011
Merci pour votre attention!Merci pour votre attention!
15Journées Scientifiques de l’EDOM March 8, 2011
Ultrashort approach: contrast
HCFXPW
- Pre-pulses are removed.- Contrast ratio is estimated to be 10-10.