4 th Satellite Workshop on Photon Beam Diagnostics 28 th January 2016 DESY Campus, Hamburg. Danielle Dowek

Transcription

1 4 th Satellite Workshop on Photon Beam Diagnostics 28 th January 2016 DESY Campus, Hamburg Molecular polarimetry: a mean to determine the complete polarization state of the ionizing light (Stokes parameters s1, s2, s3) in the VUV-soft Xray range, based on molecular frame photoemission Danielle Dowek Institut des Sciences Moléculaires d Orsay (ISMO) OPT2X Lidex Project Paris-Saclay University

2 Control and characterization of polarization in the XUV and X-ray range Need for circularly polarized, bright, coherent «chiral» light to study the chiral properties of matter : biomolecules, magnetic materials particular timely to produce and control ultra-short CP pulses to investigate time resolved dynamics - Synchrotron radiation: X-ray range, VUV F. Schäfers et al., Appl. Opt. 38, 4074 (1999); L. Nahon and C. Alcaraz, Appl. Opt. 43, 1024 (2004). - Free Electron Lasers: FERMI FEL E. Allaria et al Phys. Rev. X 4, (2014) Mazza et al Nat. Comm (2014): AR-PES on IR+XUV ATI of He - Circularly polarized plasma-based soft X-ray laser A. Depresseux et al Phys. Rev. Lett. 115, (2015) /B. Vodungbo et al Opt. Expr. 19, 4346 (2011) - Elliptically polarized high-order harmonics (HHG) O. Kfir et al Nature photonics 9, 99 (2015) X. Zhou et al Phys. Rev. Lett. 102, (2009) A. Ferré et al Nat. photon. 9, 93 (2015) G. Lambert et al Nat. Comm (2015) Complete characterization of the polarization state of the ionizing light based on 2 MFPADs, including the degree of polarization

3 Molecular Frame Photoelectron Angular Distributions: MFPADs most complete observable in photoionization dynamics NO (X 2 Π, 4σ 2 5σ 2 1π 4 2π 1 ) + hν NO + (c 3 Π 4σ -1 ) + e (l,λ) (hν 22 ev, XUV) P χ z MF θ e (φ e ) V elec x MF N T fi (χ, θ e, φ e ) O Linear polarization hν = ev Polar and azimuthal dependence of MF photoemission for each orientation χ of the polarisation relative to the molecular axis Lucchese et al PRA 65, (2002); Lafosse et al PRL 84, 5987 (2000) 3

4 Circular dichroism in the molecular frame: MF-CDAD NO (X 2 Π, 4σ 2 5σ 2 1π 4 2π 1 ) + hν NO + (c 3 Π 4σ -1 ) + e (l,λ) (hν 22 ev, XUV) N N S 3 =-1 T fi (χ, θ e, φ e ) O S 3 =1 O Linear polarization hν = ev Circular polarization Dubbs et al, PRL, 54, 1249 (1985) Cherepkov et al Z. Phys. D (1987) Schönhense Phys. Scripta 31, 4255 (1989) Jahnke et al, PRL 88, (2002)

5 Circular dichroism in the molecular frame: MF-CDAD NO (X 2 Π, 4σ 2 5σ 2 1π 4 2π 1 ) + hν NO + (c 3 Π 4σ -1 ) + e (l,λ) (hν 22 ev, XUV) N N S 3 =-1 ILCP I e RCP e CDAD( θe) = I + I LCP ( θ ) ( θ ) ( θ ) ( θ ) e RCP e O S 3 =1 Circular dichroism O Linear polarization CDAD θ(deg) hν = ev Gessner et al PRL (2002); Lebech et al JCP 118, 9653 (2003);

6 Electron-ion 3D coincidence momentum spectroscopy in Dissociative PhotoIonization of small molecules AB + hν (ê) AB + + e A + + B + e (V e, V A+, ê) (x MF ) V (z n MF) χ θe Ve ê (θ e,φ e ) (N +,e) T fi (χ, θ e, φ e ) DESIRS beam-line 5-40 ev valence & inner-valence PI PLEIADES inner-shell PI Rep-rate of the light source: SOLEIL (few bunch mode T=147 ns) 7MHz Coincidences: n events/pulse << 1 Lafosse et al PRL (2000) ; Lebech et al RSI (2002); L. Nahon et al J. Synch. Rad. 19, 508 (2012)

7 Electron-ion 3D coincidence momentum spectroscopy in Dissociative PhotoIonization of small molecules: soft X-rays and light sources AB + hν (ê) AB ++ + e ph + e Au A + + B + + e ph + e Au (V e, V A+, V B+, ê) MCP Ion PSD Λ i DESIRS-VUV PLEIADES-soft X-ray T=140 ns ; δt 50 ps Saclay Laser-matter Interaction Center Femto laser, HHG ê K-shell ionization of CO and NO. Xi, Yi, Ti X e, Y e,t e E extr Supersonic jet SAPHIRS C(1s): 284 ev, N(1s) 410 ev, O(1s) 543 ev MCP Λ e W.B. Li et al PRA 75, (2007); Jahnke et al, PRL 88, (2002) Electron PSD PSD: Roentdek Sources of ultrashort XUV & X-ray pulses: Femtosecond lasers and HHG XUV sources x 1 khz FELs : European XFEL pulses/s Efficient methods for the multidimensional data analysis: Lebech et al JCP 118, 9653 (2003) Billaud et al J. Phys. B (2012) T fi ± 1 (χ,θ e,φ e ) = F 00 (θ e ) 0.5 F 20 (θ e ) P 20 (cos χ) 0.5 F 21 (θ e ) P 21 (cos χ) cos (φ e ) L N F ( θ ) = (cos ) N e C P θ L ' LN L ' e L ' 0.5 F 22 (θ e ) P 22 (cos χ) cos (2φ e ) ± F 11 (θ e ) P 11 (cos χ) sin (φ e ) 7

8 STOKES PARAMETERS ê = (s 1,s 2,s 3 ) and Polarization Ellipse Polarisation ellipse Linear component: s 1, s 2 orientation Ψ tg 2 s Ψ = 2 s 1 Ellipticity: ε = tg χ Degree of polarization: s3 sin 2 χ = s +s +s Born & Wolf P= s 1 +s 2 +s 3 =1-s4 Optical polarimetry without dephaser: Malus law 1 s = Arctg 2 s Ψ 2 s = 1-s 3ub s= s 1 +s2 Assuming P = 1: ε ub = tg 0.5 Arcsin(s 3ub ) rotational angle (analyser)

9 MFPADs INDUCED BY ELLIPTICALLY POLARIZED LIGHT T fi (χ, γ,θ e,φ e ) = ê = (s 1,s 2,s 3 ) F 00 (θ e ) + F 20 (θ e ) { 0.5 P 20 (cos χ) t 1 (γ) P 22 (cos χ) } + F 21 (θ e ) {[ 0.5 P 21 (cos χ) t 1 (γ) P 21 (cos χ)]cos (φ e ) 1.5 t 2 (γ) P 11 (cos χ) sin(φ e ) } + F 22 (θ e ) {[ 0.5 P 22 (cos χ) + t 1 (γ) (2+P 20 (cos χ))]cos(2φ e) + 3 t 2 (γ) P 10 (cos χ) sin(2φ e ) } - s 3 F 11 (θ e ) {P 11 (cos χ) sin (φ e )} with t t ( γ) = s1 cos( 2γ) + s sin ( 2γ) ( γ) = s cos( 2γ) s sin ( 2γ) ê χ V n V e (θ e,φ e ) Extraction of the 5 F LN (θ e ) functions: PI dynamics Extraction of s 3 : Molecular frame circular dichroism γ Extraction of s 1 and s 2 : Lab frame ion fragment (or photoelectron) (χ, γ) angular distribution Veyrinas et al., PRA 88, (2013)

10 Determination of the STOKES PARAMETERS (s 1,s 2,s 3 ): s 3 NO (X 2 Π, 4σ 2 5σ 2 1π 4 2π 1 ) + hν NO + (c 3 Π 4σ -1 ) + e (l,λ) Dominant DPI reaction, Large β ion anisotropy: β ion 1 Large circular dichroism (F 11 ) Circular dichroism in the molecular frame s 3 F 11 (θ e ) CDAD meas = - s 3 CDAD ref S 3 =-1 S 3 =0 S 3 = (0.02) Establish reference values of the CDAD (F 11 ) Veyrinas et al., PRA 88, (2013): MCSCI calculations R.R. Lucchese

11 Determination of the STOKES PARAMETERS (s 1,s 2,s 3 ): s 1,s 2 Photoion angular distribution in the lab frame 2D histogram (χ,γ): s 1 and s 2 T χγ 1 1 i 2 χ 1 γ 2 γ 2 χ (, ) = C 1+ β P ( cos ) + ( s cos(2 ) s sin(2 )) P ( cos ) Integration (θ e, φ e ) 500 Intensité [u.a.] χ [deg.] Intensité [u.a.] γ [deg.] Intensité [u.a.] γ [deg.] Intensité [u.a.] γ [deg.] βn + T ( γ ) = C 1 + ( s1cos 2γ s2 sin 2 γ) 2 S 1 = -0.96, S 2 = S 1 = -0.01, S 2 = S 1 = -0,07 S 2 = 0.02 s ± 0.01 Veyrinas et al., PRA 88, (2013)

12 DETERMINATION of the 3 STOKES PARAMETERS Photoion angular distribution in the lab frame 2D histogram (χ,γ): s 1 and s 2 T χγ 1 1 i 2 χ 1 γ 2 γ 2 χ (, ) = C 1+ β P ( cos ) + ( s cos(2 ) s sin(2 )) P ( cos ) Integration (θ e, φ e ) 500 Intensité [u.a.] χ [deg.] Intensité [u.a.] γ [deg.] Intensité [u.a.] γ [deg.] Intensité [u.a.] γ [deg.] βn + T ( γ ) = C 1 + ( s1cos 2γ s2 sin 2 γ) 2 OP & MP (s 1,s 2,s 3 ) P = (1-s 4 ) 12 Veyrinas et al., PRA 88, (2013)

13 Polarization state of HHG XUV Attosecond Pulse Train HHG in SF 6 molecules induced by elliptically polarized IR (moderate) A. Ferré et al Nat. Phot. 9 (201 4) Production of large «ellipticities» ε ub = E ext B PLFA beam line (10 mj, 1 khz, 800 nm, 50 fs) CEA (Saclay) S.J. Weber et al RSI 86, (2015) CIEL COLTRIMS Gisselbrecht et al., RSI 76, (2005) Lebech et al., RSI 73, 1866 (2002)

14 Results: HHG from SF 6 molecules ε (IR) = 0.2 Bmdd-bande-1-bp3.txt 90 deg coupe az : Bmdd-bande-2-bp3.txt 90 deg coupe az : Bmdd-bande-3-bp3.txt 90 deg coupe az : Bmdd-bande-4-bp3-lmax=8.txt 90 deg coupe az : ε 0.84(0.07) ε 0.65(0.05) ε 0.26(0,04) ε 0.11 (0,04) Reference DESIRS SOLEIL S 3 1 Veyrinas, Gruson et al in preparation (2016) Int [u.a.] H15 H17 H19 H E e [ev] H23 H25 Task: «polarization diagnostic for probing HHG mechanisms?» OPT2X project: 7 labs Université Paris-Saclay XUV Beamline instruments ATTOLAB: FAB 10 (10kHz) Multilayer optical polarimeters

15 OPT2X: Polarization control Development of a versatile ML based optical polarizer for ultrashort XUV pulses Linearly polarized XUV π/8 phase shift at each reflection Circularly polarized XUV π/2 phase shift Polarizer transmission Work in progress (2016) Photon Energy (ev) ML photon energies 8-100eV Reflectivity: 3-64% S3 99,7% for monochromatic XUV M. Dehlinger, F. Delmotte (LCF) Optics characterization: SOLEIL L.Nahon WG1 OPT2X

16 Conclusion and perspectives Molecular frame photoemission: A sensitive in situ probe of the complete polarization state of XUV and X-ray radiation in one-xuv or X-ray photon ionization: Full polarization ellipse (s 1, s 2, s 3 ), including the degree of polarization disentanglement of s 3 and s 4 Need to establish reference value for the CDAD (exp and/or theory) Extended photon energy range, tunability with the phototelectron energy Inner-valence and K /L shell ionization CO, NO, CS2. C(1s), O(1s), N(1s), S(2p), F(1s) Electron-ion coincident momentum spectroscopy Take advantage of High rep rate of XFEL and the existence of COLTRIMS instruments Characterization of high harmonics elliptically polarized XUV attosecond pulses when symmetry breaking occurs: HHG from aligned molecules: origin of depolarization? Role of shape resonance n PI of SF6: amplification of ellipticity Counter rotating bichromatic fields (O. Cohen et al) Integration in beamlines

17 Acknowledgments K. Veyrinas, S. Marggi-Poullain, N. Saquet, J.C. Houver (ISMO) M. Lebech (Niels Bohr Institute, Copenhagen) R. R. Lucchese (Texas A&M University) L. Nahon, G. Garcia et al DESIRS beamline (SOLEIL) J. Bozek, C. Miron, C. Nicolas, M. Patanen PLEIADES beamline (SOLEIL) V. Gruson, S. Weber, L. Barreau, A. Camper, T. Ruchon, B. Carré, P. Salières et al J.F. Hergott, F. Lepetit et al Attophysics and SLICS (LIDyL, CEA, Saclay) M. Simon, L. Journel, R. Guillemin (LCPMR, UPMC) F. Martín et al (UAM Madrid) ATTOLAB, OPT2X Thank you for your attention