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Bright Coherent Ultrafast X-Ray Beams on a Tabletop and Applications in Nano and Materials Science

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Bright Coherent Ultrafast X-Ray Beams on a Tabletop and Applications in Nano and Materials Science Bright Coherent Ultrafast X-Ray Beams on a Tabletop and Applications in Nano and Materials Science 7.7 Å 14 Å Surprising new science I. Nonlinear optics at the extreme — Efficiently combine >5000 mid-IR laser photons PRL 109, 073004 (2012) — Bright keV x-rays from tabletop lasers — Bright tabletop hard x-ray beams? Zeptosecond pulses? 7.7 Å 14 Å II. Probing the nanoworld at the space-time limits Science 336, 1287 (2012) Capture coupled spin/charge/phonon/photon dynamics — Nature Comm 3, 1037 (2012) Nature Comm 3, 1069 (2012) — Imaging at the wavelength limit — Applications in nano science, nanotechnology, energy, materials, bio science and engineering Excellent students and collaborators Tenio Popmintchev, Ming-Chang Chen, Chan La-O-Vorakiat, Emrah Turgut, Agnieszka Becker, Andreas Becker, Adra Carr, Margaret Murnane, Henry Kapteyn JILA, University of Colorado, Boulder Andrius Baltuška Technical University Vienna Carlos Hernández-García, Luis Plaja University of Salamanca Alexander Gaeta Cornell Tom Silva, Justin Shaw, Hans Nembach NIST Stefan Mathias, Martin Aeschlimann, Claus Schneider Kaiserslautern and Julich Michael Bauer Kiel University Keith Nelson MIT Tamar Seideman, Sai Ramakrishna Northwestern Xiao-Min Tong Tsukuba University Visible laser light benefits society Surgery Welding Optics Communications Material Processing Remote Ranging Sensing Holography Atomic Molecular Optical Science storage 4 X-ray light also benefits society Wilhelm Roentgen 1895 X-ray tube X-ray lasers and free electron lasers 3 Spontaneous emission A21 8πhν 3 = 3 ∝ν Stimulated emission B21 c x-ray beam $ 1 '$ 1' 1 Power ∝& )& ) hν ∝ x-ray beam € & ) ( ) 5 % σ g (% τ ( λ € Soft x-ray laser at 20nm X-ray free electron laser at 1.5nm (D. Matthews 1985) (K. Hodgson 2009) The birth of Nonlinear Optics – second harmonic generation P.A. Franken et al, PRL 7, 118 (1961) 347nm Ruby laser 694nm Lens Quartz crystal Prism Photographic plate The birth of Nonlinear Optics – second harmonic generation P.A. Franken et al, PRL 7, 118 (1961) 347nm Ruby laser 694nm Lens Quartz crystal Prism Photographic plate Laser Nonlinear field electron motion iωt EP(ω)=E0 iωt i2ωt d(ω)=a1e + a2e +… t ω + ω = 2ω High harmonics - coherent version of X-Ray tube x-ray beam High Harmonic Generation (McPherson et al, JOSA B 4, 595 (‘87); Ferray et al, J Phys B 21, L31 (‘88)) 1895 Röntgen X-ray Tube Extreme nonlinear optics - high harmonic generation x-ray beam Corkum, PRL 71, 1994 (1993) Kulander, Schafer, Krause, SILAP Proceedings, 95 (1992-3) Kuchiev, JETP 45, 404 (1987) Extreme nonlinear optics - high harmonic generation x-ray beam Corkum, PRL 71, 1994 (1993) Kulander, Schafer, Krause, SILAP Proceedings, 95 (1992-3) Kuchiev, JETP 45, 404 (1987) High harmonic generation – microscopic physics x-ray beam Broad bandwidth Harmonics from single atom cutoff 2 hνcutoff = Ip+3.2Up ≈ ILλ ionization potential energy of e- Corkum, PRL 71, 1994 (1993) Kulander, Schafer, Krause, SILAP Proceedings, 95 (1992-3) Kuchiev, JETP 45, 404 (1987) High Harmonic Generation – single atom quantum picture t 3 * −iS( p,t,t') x(t) = i∫ dt ! ∫ d p dx [p − A (t)]e E(t ! )dx[p − A (t ! )] + c.c. 0 Tunnel ionization Propagation Recombination ~ 100 Bohrradii Krause, Schafer, Kulander, PRL 68, 3535 (1992) Lewenstein, PRA 49, 2117 (1994) Laser pulse determines the HHG energy and phase 14 Challenge for HHG – macroscopic phase matching Driving laser field Harmonic field - + VLaser=VX-ray= c - + Challenge for HHG – macroscopic phase matching Driving laser field VLaser > C Harmonic field - VX-ray = C + - + Efficient HHG requires phase velocity matching Laser field ionization • Refractive index (phase VLaser > C velocity) of laser is time dependent! VX-ray = C Pressure tuned phase velocity matching • Place gas inside a hollow fiber • Tune the gas pressure to equalize the laser and x-ray phase velocities laser field Δk = qklaser - kHHG = 0 0.% u2 ( % (02 11 λ0 2π Δk = q/' * − P' (1−η) Δδ −η[Natmreλ0 ]*3 0 4πa2 λ 0 VLaser=VX-ray=C 1& ) & 0 )4 Science 280, 1412 (1998) Waveguide Neutrals Plasma Science 297, 376 (2002) € Pressure tuned phase velocity matching • Place gas inside a hollow fiber • Tune the gas pressure to equalize the laser and x-ray phase velocities laser field Fully coherent, laser-like, extreme ultraviolet high harmonic beams VLaser=VX-ray=C Science 280, 1412 (1998) Science 297, 376 (2002) Limits of phase matching • Turning up laser intensity creates plasma that speeds up laser phase velocity • Defines critical ionization/photon energy above which phase matching impossible (150eV) 2 hνSingle atom cutoff ∝ ILλL 0.% u2 ( % (02 11 λ0 2π Δk = q/' * − P' (1−η) Δδ −η[Natmreλ0 ]*3 0 4πa2 λ 0 Vlaser ≠ C 1& ) & 0 )4 Waveguide Neutrals Plasma € Limits of phase matching • Turning up laser intensity creates plasma that speeds up laser phase velocity • Defines critical ionization/photon energy above which phase matching impossible (150eV) 2 hνSingle atom cutoff ∝ ILλL Seres, Brief Communication, Nature 433, 596 (2005) 0.% u2 ( % (02 11 λ0 2π Δk = q/' * − P' (1−η) Δδ −η[Natmreλ0 ]*3 0 4πa2 λ 0 Vlaser ≠ C 1& ) & 0 )4 Waveguide Neutrals Plasma € High harmonic generation using long wavelength lasers 2 Single atom HHG: hνSingle atom cutoff ∝ ILλL Electron trajectory λL= 0.8µm Electron wavepacket spreading due to quantum diffusion means single atom yield scales λ = 1.6µm L -5.5 ∝ λL Sheehy, Schafer, Gaarde, PRL 83, 5270 (1999) Tate et al.,PRL 98, 013901 (2007) Schiessl et al., PRL 99 253903 (2007) Frolov et al., PRL 100, 173001 (2008) Phase matching in mid-IR overcomes low single-atom yield! hν ∝ I λ 2 Single-atom cutoff L L 1.7 hνPhase matched cutoff ∝ ILλL • Mid-IR driving lasers 0.% u2 ( % (02 11 λ0 2π Δk = q/' 2 * − P' (1−η) Δδ −η[Natmreλ0 ]*3 extend HHG phase 10& 4πa ) & λ0 )40 matching to > keV Ti:Sapphire • Counterintuitive finding: € MIR phase matching can overcome low single-atom yield since gas pressure and transparency increase! Extending bright high harmonics into the soft x-ray region 2 hνSingle atom HHG∝ ILλL hν ∝ I λ 1.7 0.8µm Phase matched HHG L L 2µm 4µm 4000 nm Coherent x-ray supercontinuum reaching 8Å 1.3 m 2µm 0.8µm µ > 5000 order nonlinear process! λLASER=3.9 µm B C N O Fe Co Ni Cu • Bright coherent tabletop keV x-rays for first time Popmintchev et al., Prov. US Patent (2008); CLEO Postdeadline (2008); • Near theoretically-limited (absorption-limited) Opt. Lett. 33, 2128 (2008); efficiency to keV! (> 10-5/pulse in 1% bandwidth) PNAS 106, 10516 (2009); Nature Photonics 4, 822 (2010). Chen et al., PRL 105, 173901 (2010). Popmintchev et al., CLEO Postdeadline (2011). Science 336, 1287 (2012). Coherent x-ray supercontinuum reaching 8Å 1.3 m 2µm 0.8µm µ > 5000 order nonlinear process! λLASER=3.9 µm B C N O Fe Co Ni Cu FLAT EFFICIENCY INTO keV! 10-5/pulse in 1% bandwidth • Bright coherent tabletop keV x-rays for first time • Near theoretically-limited (absorption-limited) efficiency to keV! (> 10-5/pulse in 1% bandwidth) Dramatic progress in bright tabletop high harmonics m µ 3.9 m µ m µ 2.0 m 0.8 µ Phase-Matched 1.3 Popmintchev et al. Opt. Lett. 33, 2128 (2008) Year PNAS 106, 10516 (2009) PRL 105, 173901 (2010) Nature Photonics 4, 822 (2010) Science 336, 1287 (2012) Broadest supercontinuum to date - 2.5 as pulses! Uncertainty principle - FWHM τX-ray [as] ΔEX-ray[keV]~1.8 >0.7 keV >1.3 keV Bright EUV and soft x-ray attosecond pulses EUV Soft x-ray ΔE ≈ 700 eV ΔE ≈ 7 eV Δt ≈ 2 as Δt ≈ 210 as Time (fs) Opt. Express 17, 4611 (2009) Science 336, 1287 (2012) Coherent laser-like x-ray beams from 1 – 30 nm θ ≈ λ/d 30nm HHG beam 13nm HHG beam 3nm HHG beam Young, Philos. Trans. R. Soc. XCII 12, 387 (1802) Bartels et al, Science 297, 376 (2002) Zhang et al, Optics Letters 29, 1357 (2004) Popmintchev et al, Nature Photonics 4, 822 (2010) Chen et al, PRL 105, 173901 (2010) Popmintchev et al, Science 336, 1287 (2012) 1nm HHG beam Bright, tabletop, coherent keV X-ray beams Incoherent X-ray Coherent X-ray SupercontinuaHe 7.7-43 Å Ne 14-43 Å He 7.7-43 Å Supercontinua Roentgen, Double X-ray beam INCOHERENT SIMULATION Nature (1896). slit COHERENT SIMULATION EXPERIMENT 5-5-5 µm He 7.7-43 Å Ne 14-43 Å He 7.7-43 Å INCOHERENT SIMULATION COHERENT SIMULATION EXPERIMENT Popmintchev et al., Science 336, 1287 (2012). Limits of high harmonic generation? • He driven by 20 µm mid-IR lasers may generate bright 25 keV beams • ≈ ½ million order phase matched nonlinear process! Coherent x-ray tube The power of x-rays NANO-METROLOGY 1 meter (1 m) child 1 millimeter (10-3 m) blood cell Dynamic metrology of advanced thick magnetic virus nanostructures (< 10nm) 1 micrometer (10-6 m) DNA transistor nanotubes 1 nanometer (10-9 m) Protein water molecule crystallography atom spacing 1 picometer (10-12 m) size of nucleus -15 1 femtometer (10 m) X-rays are ideal probes of the nanoworld: • Penetrate thick objects • Image small features • Elemental and chemical specificity • Capture all dynamics relevant to function The power of x-rays 1 meter (1 m) child 1 millimeter (10-3 m) blood cell virus 1 micrometer (10-6 m) DNA transistor nanotubes 1 nanometer (10-9 m) water molecule atom spacing 1 picometer (10-12 m) Stohr et al. size of nucleus -15 1 femtometer (10 m) X-rays are ideal probes of the nanoworld: • Penetrate thick objects • Image small features • Elemental and chemical specificity • Capture all dynamics relevant to function The power of ultrafast x-rays 1 sec (1 s) clock tick 1 millisecond (10-3 s) camera shutter camera 1 microsecond (10-6 s) flash 1 nanosecond (10-9 s) processor speed data storage rotations -12 1 picosecond (10 s) bond breaking
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