Spatio-temporal coherence of free electron laser pulses in the soft x-ray regime.

The temporal coherence properties of soft x-ray free electron laser pulses at FLASH are measured at 23.9 nm by interfering two time-delayed partial beams directly on a CCD camera. The partial beams are obtained by wave front beam splitting in an autocorrelator operating at photon energies from h nu = 30 to 200 eV. At zero delay a visibility of (0.63+/- 0.04) is measured. The delay of one partial beam reveals a coherence time of 6 fs at 23.9 nm. The visibility further displays a non-monotonic decay, which can be rationalized by the presence of multiple pulse structure.

[1]  C. Bostedt,et al.  Multistep ionization of argon clusters in intense femtosecond extreme ultraviolet pulses. , 2008, Physical review letters.

[2]  S. Eisebitt,et al.  Lensless imaging of magnetic nanostructures by X-ray spectro-holography , 2004, Nature.

[3]  P. Nicolosi,et al.  First operation of a free-electron laser generating GW power radiation at 32 nm wavelength , 2006 .

[4]  H. Wabnitz,et al.  Multiple ionization of atom clusters by intense soft X-rays from a free-electron laser , 2002, Nature.

[5]  Richard A. London,et al.  Femtosecond time-delay X-ray holography , 2007, Nature.

[6]  W. H. Benner,et al.  Femtosecond diffractive imaging with a soft-X-ray free-electron laser , 2006, physics/0610044.

[7]  Statistical properties of the radiation from VUV FEL at DESY operating at 30 nm wavelength in the femtosecond regime , 2005, physics/0511234.

[8]  Rick Trebino,et al.  Measuring ultrashort laser pulses in the time-frequency domain using frequency-resolved optical gating , 1997 .

[9]  M. V. Yurkov,et al.  Coherence properties of the radiation from X-ray free electron laser , 2006 .

[10]  M. Richter,et al.  Photoelectric effect at ultrahigh intensities. , 2007, Physical review letters.

[11]  M. V. Yurkov,et al.  Statistical properties of the radiation from VUV-FEL at DESY (Femtosecond mode of operation) , 2006 .

[12]  J T Costello,et al.  Spectroscopic characterization of vacuum ultraviolet free electron laser pulses. , 2006, Optics letters.

[13]  T. Noll,et al.  An x-ray autocorrelator and delay line for the VUV-FEL at TTF/DESY , 2005, SPIE Optics + Photonics.

[14]  Zhirong Huang,et al.  Z-dependent spectral measurements of SASE FEL radiation at APS. , 2003 .

[15]  R. Ischebeck,et al.  Study of the transverse coherence at the TTF free electron laser , 2003 .

[16]  David Garzella,et al.  Injection of harmonics generated in gas in a free-electron laser providing intense and coherent extreme-ultraviolet light , 2008 .

[17]  S. Milton,et al.  Characterization of a chaotic optical field using a high-gain, self-amplified free-electron laser. , 2003, Physical review letters.

[18]  Ryszard S. Romaniuk,et al.  Operation of a free-electron laser from the extreme ultraviolet to the water window , 2007 .

[19]  S. Krinsky,et al.  Statistical analysis of the chaotic optical field from a self-amplified spontaneous-emission free-electron laser. , 2006, Physical review. E, Statistical, nonlinear, and soft matter physics.