1. Imperial College London Imperial College XUV Attosecond Beamline: progress and results to date Charles Haworth Laser Consortium Imperial College London Supervisor: Dr. John Tisch

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

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

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

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

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

7. Imperial College London 0 bar Tunable pulse duration 2.5 bar neon 1.5 bar neon 2.5 bar neon - chirped 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 = 28fsFWHM = 7fs FWHM = 18.5fs

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

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

10. Imperial College London XUV SPIDER 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 plasma ~100µm Spatially Resolved HHG Spectra (initial data!)

11. Imperial College London Latest fringe data (much cleaner and controllable)

12. Imperial College London Drescher, Science,291 pg1923,2001

13. Imperial College London MoSi Mirror 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 X-ray UHV mirror mount for atomic streak camera

14. Imperial College London 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)

15. Imperial College London 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 5mm 4mm

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

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

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

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

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