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Attosecond technology meeting RAL: 7/12/2005

Attosecond technology meeting RAL: 7/12/2005. Imperial College XUV Attosecond Beamline: progress and results to date Charles Haworth Laser Consortium Imperial College London Supervisor: Dr. John Tisch. intensity. spectral comb. Long pulse. . pulse train. t. many recollisions.

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Attosecond technology meeting RAL: 7/12/2005

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  1. Attosecond technology meeting RAL: 7/12/2005 Imperial College XUV Attosecond Beamline: progress and results to date Charles Haworth Laser Consortium Imperial College London Supervisor: Dr. John Tisch Imperial College London

  2. intensity spectral comb Long pulse  pulse train t many recollisions Few-cycle pulse t continuum intensity  single recollision of maximum energy single pulse Creation of isolated attosecond pulses + + Imperial College London

  3. 6.5fs 200mW 650-900nm 450mW 30fs 800mW 1kHz The few-cycle driving laser Imperial College London

  4. IR Pulse measurement with FROG Retrieved trace Experimental trace Wavelength (nm) Wavelength (nm) Time (fs) Time (fs) Retrieved temporal amplitude & phase Retrieved spectral amplitude & phase Time (fs) Wavelength (nm) Imperial College London

  5. Phase stabiliser The few-cycle driving laser Imperial College London

  6. Fast phase stabilisation A. Baltuska, et al., Nature 421, 611 (2003) Imperial College London

  7. Tunable pulse duration 2.5 bar neon - chirped 0 bar 1.5 bar neon 2.5 bar neon Pressure tuning of pulse duration Adjustment of gas pressure in differentially pumped fibre permits the generation of near-transform-limited pulses in the range 7-30fs, with constant energy and alignment. This provides clean pulses without significant satellites c.f. chirping maximum bandwidth, which introduces significant pulse distortion due to the modulated nature of the self-phase modulated spectrum. FWHM = 18.5fs FWHM = 7fs FWHM = 18.5fs FWHM = 28fs Imperial College London

  8. High harmonic generation f=40cm mirror Imperial College London

  9. Increasing harmonic order Increasing harmonic order Harmonic spectrum Measured harmonic spectra Calculated harmonic spectra Divergence 46nm Wavelength 12nm Divergence Imperial College London

  10. XUV SPIDER Spatially Resolved HHG Spectra (initial data!) Spatially encoded XUV SPIDER Preliminary tests Fringing observed in the harmonic signal from two spatially separated foci We have observed very clear spatial and spectral fringes in the harmonic spectra nozzle ~100µm plasma plasma Imperial College London

  11. Fringes in harmonic spectra Latest fringe data (much cleaner and controllable) Imperial College London

  12. Atomic streak camera Drescher, Science,291 pg1923,2001 Imperial College London

  13. MoSi Mirror X-ray UHV mirror mount for atomic streak camera Engineering the atomic streak camera for metrology of attosecond pulses Developing methods of coring and mounting the MoSi multilayer mirror used as the XUV/IR delay stage. Testing needle gas targets Imperial College London

  14. Coring process Cored two-part mirror Have MoSi mirror from NTT Japan (13nm centre wavelength, 10 bilayers) Tests indicate that core can be cut in-house with minimal damage to the substrate and coating Damage occurs close to the cut and should not adversely affect focusing of either the XUV or infrared pulses. core cutting gap (kerf) Imperial College London

  15. Atto management meeting 09/05 MoSi multilayer 2-part mirror for Atomic Streak Camera Centre part mounted on stalk ready for attachment to piezo stage Annular part mounted in UHV motorised mount 4mm 5mm Imperial College London

  16. MoSi mirror profile Mirror reflectivity Mirror phase CXRO website http://www.cxro.lbl.gov/ Wavelength (nm) Imperial College London

  17. 3D surface plot of neon harmonics Position Intensity Wavelength Neon HHG spectrum Lineout of harmonic spectrum Reflected XUV spectrum Intensity (arb. units) Wavelength (nm) Imperial College London

  18. 3D surface plot of optimised neon harmonics Intensity Position Wavelength Neon harmonics - Continuum 300as pulse duration Intensity Limited by MoSi mirror bandwidth! Time Imperial College London

  19. New beamline!!!!! Imperial College London

  20. Acknowledgements Thanks to…. John,Jon and Roland Joe Robinson Andy Gregory and Peter Ruthven All the other atto people! Imperial College London

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