Kaertner, F. X.

Paper	Title	Page
TUBAU02	Femtosecond Synchronization and Stabilization Techniques	287
	J. Kim, J. Chen, F. X. Kaertner MIT, Cambridge, Massachusetts F. Ludwig DESY, Hamburg Z. Zhang Peking University, School of Physics, Beijing
	Future seeded X-ray free electron laser facilities will be based on an intricate interplay between ultrafast lasers and RF-driven accelerators. To develop the full potential of these new ultrafast X-ray sources, tight synchronization between the laser pulses and the electron bunches on the scale of a few femtoseconds is necessary over several kilometres of distance. In this paper, we present optical synchronization and stabilization techniques that enable the implementation of a long-term stable femtosecond timing and synchronization system. For optical-to-RF synchronization, we demonstrate an optical-microwave phase detector that is capable to extract an RF-signal from an optical pulse train with less than 5 fs timing jitter [1 Hz, 10MHz]. Scaling of this component to sub-femtosecond resolution is discussed. Optical-to-optical synchronization of multiple femtosecond lasers with sub-femtosecond precision over more than 12 hours is demonstrated. In addition, first results on optically stabilized fiber links for timing distribution will be presented. Together with low noise mode-locked lasers, a flexible femtosecond timing distribution system can be constructed.
	Slides
	Talk
MOPPH054	FERMI @ Elettra: A Seeded FEL Facility for EUV and Soft X-Rays	166
	J. N. Corlett, L. R. Doolittle, W. M. Fawley, S. M. Lidia, G. Penn, I. V. Pogorelov, J. Qiang, A. Ratti, J. W. Staples, R. B. Wilcox, A. Zholents LBNL, Berkeley, California E. Allaria, C. J. Bocchetta, D. Bulfone, F. C. Cargnello, D. Cocco, P. Craievich, G. D'Auria, M. B. Danailov, G. De Ninno, S. Di Mitri, B. Diviacco, M. Ferianis, A. Galimberti, A. Gambitta, M. Giannini, F. Iazzourene, E. Karantzoulis, M. Lonza, F. M. Mazzolini, G. Penco, L. Rumiz, S. Spampinati, G. Tromba, M. Trovo, A. Vascotto, M. Veronese, M. Zangrando ELETTRA, Basovizza, Trieste M. Cornacchia, P. Emma, Z. Huang, J. Wu SLAC, Menlo Park, California W. Graves, F. X. Kaertner, D. Wang MIT, Middleton, Massachusetts
	We describe the conceptual design and major performance parameters for the FERMI FEL project funded for construction at the Sincrotrone Trieste, Italy. This user facility complements the existing storage ring light source at Sincrotrone Trieste, and will be the first facility to be based on seeded harmonic cascade FELs. Seeded FELs provide high peak-power pulses, with controlled temporal duration of the coherent output allowing tailored x-ray output for time-domain explorations with short pulses of 100 fs or less, and high resolution with output bandwidths of the order of meV. The facility uses the existing 1.2 GeV S-band linac, driven by electron beam from a new high-brightness rf photocathode gun, and will provide tunable output over a range from ~100 nm to ~10 nm, and APPLE undulator radiators allow control of x-ray polarization. Initially, two FEL cascades are planned, a single-stage harmonic generation to operate over ~100 nm to ~40 nm, and a two-stage cascade operating from ~40 nm to ~10 nm or shorter wavelengh, each with spatially and temporally coherent output, and peak power in the GW range.