1 Journées Scientifiques de lEDOM March 8, fs laser chain based on optical parametric chirped pulse amplification Lourdes Patricia Ramirez Equipe Lasers Solides et Applications Laboratoire Charles Fabry de lInstitut dOptique (LCFIO), Palaiseau, France Frédéric Druon Directeur de thèse

2 Journées Scientifiques de lEDOM March 8, 2011 Outline 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

3 Journées Scientifiques de lEDOM March 8, 2011 Front end of the Apollon 10 PW laser High contrast, CEP stable, sub-10 fs, >100 µJ, 1 kHz Ultrashort seed 800 nm HEC-DPSSL pumped high rep-rate amplifiers (Yb:KGW, YAG, CaF 2 ) nm, Hz SHG: ps-ns nm Hz Pump 515 nm NOPCPA (BBO or LBO) Optical synchronization Noncollinear Optical Parametric Chirped Pulse Amplification stages <10 fs, 100 nm, Hz 10 TW! Applications: high harmonic generation, attosecond physics, particle acceleration, plasma physics, high energy physics experiments

4 Journées Scientifiques de lEDOM March 8, 2011 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 Crystal X (2) Nonlinear Crystal X (2) pump signal residual pump amplified signal idler signal idler Generation Amplification

5 Journées Scientifiques de lEDOM March 8, 2011 Chirped pulse amplification (CPA)

6 Journées Scientifiques de lEDOM March 8, 2011 OPA + CPA = OPCPA Replace with nonlinear crystals e.g. BBO, LBO, KDP

7 Journées Scientifiques de lEDOM March 8, 2011 Front end of the Apollon 10 PW laser High contrast, CEP stable, sub-10 fs, >100 µJ, 1 kHz Ultrashort seed 800 nm HEC-DPSSL pumped high rep-rate amplifiers (Yb:KGW, YAG, CaF 2 ) nm, Hz SHG: ps-ns nm Hz Pump 515 nm NOPCPA (BBO or LBO) Optical synchronization Noncollinear Optical Parametric Chirped Pulse Amplification stages <10 fs, 100 nm, Hz 10 TW!

8 Journées Scientifiques de lEDOM March 8, 2011 Ultrashort seed source Sub-10 fs, >100 µJ, 1 kHz, CEP stable, high contrast ratio at 800 nm 2 approaches: Commercial ultrashort Ti:Sa system 25 fs, 1.5 mJ, 1 kHz, CEP stable, CR ~ 10 8 Ultrashort approach: 5 fs Hollow core fiber (HCF) pulse compression Cross polarized wave generation (XPW) 5 fs, 100 µJ, CEP preserving, CR ~ Main disadvantages: low efficiency - Compression in between two stages Direct XPW: Sub-10 fs approach Spectral broadening and contrast enhancement via cross polarized wave generation only < 10 fs, µJ, CEP preserving, CR ~ Advantages: higher efficiency -Single stage for broadening and contrast enhancement -Simple and compact setup

9 Journées Scientifiques de lEDOM March 8, 2011 Ultrashort approach: hollow fiber compression Pulse compression: 25 fs to 4.4 fs Spectral broadening in the HCF: 60 nm to 250 nm >750 µJ 1.4mJ, 25fs >850 µJ 60nm Laser HCF

10 Journées Scientifiques de lEDOM March 8, 2011 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 crystals third-order nonlinearity tensor. Glan 1Glan 2 BaF 2 χ (3) Main features: - Contrast enhancement: depends on the polarizer exctinction ratio (10 5 ) -Temporal pulse shortening: -Spectral cleaning and broadening

11 Journées Scientifiques de lEDOM March 8, 2011 Ultrashort approach: HCF + XPW Energy/Spectrum FROG 3ω/f-2f ~80 μJ, 5fs ~550μJ, 5fs ~100μJ Spectral cleaning with XPW: 250 nm to 200 nm XPW HCF Main result: HCF + XPW 5 fs, 100 μJ Compression: 5 fs

12 Journées Scientifiques de lEDOM March 8, 2011 Direct XPW 2.5-mm BaF 2 f = 1.5 m 20-cm hollow core waveguide Polarizer XPW cm Spatial profile of XPW beam Filtered spatial profile of laser beam Actual spatial profile of laser beam ff 1.5 mJ 25 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

13 Journées Scientifiques de lEDOM March 8, 2011 Summary 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, contrast ratio -Direct cross polarized wave generation: 9.6 fs, 300 µJ, contrast ratio Improving the stability and reliability of the direct XPW seed source Developing a stretcher for the seed source Perform OPCPA

14 Journées Scientifiques de lEDOM March 8, 2011 Merci pour votre attention!

15 Journées Scientifiques de lEDOM March 8, 2011 Ultrashort approach: contrast HCF XPW - Pre-pulses are removed. - Contrast ratio is estimated to be