"X-ray pulse preserving single-shot optical cross-correlation method for improved experimental temporal resolution"

M. Beye: O. Krupin, G. Hays, A. H. Reid, D. Rupp, S. de Jong, S. Lee, W.-S. Lee, Y.-D. Chuang, R. Coffee, J. P. Cryan, J. M. Glownia, A. Föhlisch, M. R. Holmes, A. R. Fry, W. E. White, C. Bostedt, A. O. Scherz, H. A. Durr, and W. F. Schlotter; Appl. Phys. Lett. , 03/20/12.

Additional Authors: O. Krupin, G. Hays, A. H. Reid, D. Rupp, S. de Jong, S. Lee, W.-S. Lee, Y.-D. Chuang, R. Coffee, J. P. Cryan, J. M. Glownia, A. Föhlisch, M. R. Holmes, A. R. Fry, W. E. White, C. Bostedt, A. O. Scherz, H. A. Durr, and W. F. Schlotter

Abstract:

We measured the relative arrival time between an optical pulse and a soft x-ray pulse from a free-electron laser. This femtosecond cross-correlation measurement was achieved by observing the change in optical reflectivity induced through the absorption of a fraction of the x-ray pulse. The main x-ray pulse energy remained available for an independent pump-probe experiment where the sample may be opaque to soft x-rays. The method was employed to correct the two-pulse delay data from a canonical pump-probe experiment and demonstrate 130 ± 20 fs (FWHM) temporal resolution. We further analyze possible timing jitter sources and point to future improvements.