title: Spectral encoding method for measuring the relative arrival time between x-ray/optical pulses.
abstract: The advent of few femtosecond x-ray light sources brings promise of x-ray/optical pump-probe experiments that can measure chemical and structural changes in the 10-100 fs time regime. Widely distributed timing systems used at x-ray Free-Electron Laser facilities are typically limited to above 50 fs fwhm jitter in active x-ray/optical synchronization. The approach of single-shot timing measurements is used to sort results in the event processing stage. This has seen wide use to accommodate the insufficient precision of active stabilization schemes. In this article, we review the current technique for "measure-and-sort" at the Linac Coherent Light Source at the SLAC National Accelerator Laboratory. The relative arrival time between an x-ray pulse and an optical pulse is measured near the experimental interaction region as a spectrally encoded cross-correlation signal. The cross-correlation provides a time-stamp for filter-and-sort algorithms used for real-time sorting. Sub-10 fs rms resolution is common in this technique, placing timing precision at the same scale as the duration of the shortest achievable x-ray pulses.
authors.affiliation: Université de Toulouse, UPS, Laboratoire Collisions Agrégats Réactivité, IRSAMC, F-31062 Toulouse, France.
authors.forename: M R
authors.initials: MR
authors.lastname: Bionta
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: N
authors.initials: N
authors.lastname: Hartmann
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
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authors.lastname: Weaver
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
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authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
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authors.initials: DJ
authors.lastname: Nicholson
authors.affiliation: Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
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authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
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authors.initials: JM
authors.lastname: Glownia
authors.affiliation: Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA.
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authors.lastname: Baker
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
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authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
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authors.initials: M
authors.lastname: Chollet
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Ding
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Fritz
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Fry
authors.affiliation: Mesa Photonics, LLC., 1550 Pacheco St., Santa Fe, New Mexico 87505, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Kane
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: J
authors.initials: J
authors.lastname: Krzywinski
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: H T
authors.initials: HT
authors.lastname: Lemke
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: M
authors.initials: M
authors.lastname: Messerschmidt
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: S
authors.initials: S
authors.lastname: Schorb
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: D
authors.initials: D
authors.lastname: Zhu
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: W E
authors.initials: WE
authors.lastname: White
authors.affiliation: The Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: R N
authors.initials: RN
authors.lastname: Coffee