X-ray second harmonic generation

S Shwartz; M Fuchs; J B Hastings; Y Inubushi; T Ishikawa; T Katayama; D A Reis; T Sato; K Tono; M Yabashi; S Yudovich; S E Harris

doi:10.1103/PhysRevLett.112.163901

X-ray second harmonic generation

Phys Rev Lett. 2014 Apr 25;112(16):163901. doi: 10.1103/PhysRevLett.112.163901. Epub 2014 Apr 22.

Authors

S Shwartz¹, M Fuchs², J B Hastings³, Y Inubushi⁴, T Ishikawa⁴, T Katayama⁵, D A Reis⁶, T Sato⁴, K Tono⁵, M Yabashi⁴, S Yudovich⁷, S E Harris⁸

Affiliations

¹ Physics Department and Institute of Nanotechnology, Bar Ilan University, Ramat Gan 52900, Israel and Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.
² PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA and Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, USA.
³ The Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
⁴ RIKEN SPring-8 Center, Kouto 1-1-1 Sayo, Hyogo 679-5148, Japan.
⁵ Japan Synchrotron Radiation Research Institute, JASRI, Kouto 1-1-1 Sayo, Hyogo 679-5148, Japan.
⁶ PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA and Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
⁷ Physics Department and Institute of Nanotechnology, Bar Ilan University, Ramat Gan 52900, Israel.
⁸ Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.

PMID: 24815649
DOI: 10.1103/PhysRevLett.112.163901

Abstract

We report clear experimental evidence for second harmonic generation at hard x-ray wavelengths. Using a 1.7 Å pumping beam generated by a free electron laser, we observe second harmonic generation in diamond. The generated second harmonic is of order 10 times the background radiation, scales quadratically with pump pulse energy, and is generated over a narrow phase-matching condition. Of importance for future experiments, our results indicate that it is possible to observe nonlinear x-ray processes in crystals at pump intensities exceeding 1016 W/cm2.