Abstract
Light-matter interactions are ubiquitous, and underpin a wide range of basic research fields and applied technologies. Although optical interactions have been intensively studied, their microscopic details are often poorly understood and have so far not been directly measurable. X-ray and optical wave mixing was proposed nearly half a century ago as an atomic-scale probe of optical interactions but has not yet been observed owing to a lack of sufficiently intense X-ray sources. Here we use an X-ray laser to demonstrate X-ray and optical sum-frequency generation. The underlying nonlinearity is a reciprocal-space probe of the optically induced charges and associated microscopic fields that arise in an illuminated material. To within the experimental errors, the measured efficiency is consistent with first-principles calculations of microscopic optical polarization in diamond. The ability to probe optical interactions on the atomic scale offers new opportunities in both basic and applied areas of science.
Original language | English |
---|---|
Pages (from-to) | 603-608 |
Number of pages | 6 |
Journal | Nature |
Volume | 488 |
Issue number | 7413 |
DOIs | |
State | Published - 30 Aug 2012 |
Externally published | Yes |
Bibliographical note
Funding Information:Acknowledgements We thank J. D. Jackson, D. Vanderbilt, and J. C. H. Spence for commenting on various aspects of this work. T.E.G. was supported by the Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under contract no. DE-AC02-05CH11231. The work of S.E.H. and S.S. was supported by the US Air Force Office of Scientific Research and the US Army Research Office. D.A.R. and S.G. were supported as part of the AMOS programme within the Chemical Sciences, Geosciences,and Biosciences Division,OfficeofBasic EnergySciences,USDepartment of Energy. Portions of this research were carried out at the LCLS at SLAC National Accelerator Laboratory. LCLS is an Office of Science User Facility operated for the US Department of Energy Office of Science by Stanford University. Preliminary experiments were performed at the Advanced Light Source at Lawrence Berkeley National Laboratory.