Spooktroscopy: a ghost imaging approach to ultrafast absorption spectroscopy
ORAL
Abstract
With the advent of an X-ray free-electron laser, scientists can probe femtosecond ultrafast molecular dynamics with atomic-site specificity. One well-established technique is transient absorption spectroscopy, where transient sample absorption is determined by scanning the central photon energy and recording the resultant photoproducts. When using sub-femtosecond pulses, this method is limited in spectral resolution due to the large energy bandwidth inherent to the short pulses. Here, we present a novel technique based on the principle of ghost imaging, and demonstrate sub-bandwidth absorption spectroscopy measurements with sub-femtosecond pulses. We show both one-dimensional and two-dimensional results. Our method is applicable to any spectral measurement limited by the bandwidth or noise level of the probing source, provided the probe spectrum is known at each shot.
*This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. Use of the Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515.
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