1998/10/28 by Szu-yuan Chen, S.‐Y. Chen, A. Maksimchuk +3 · 265 citations
Physics and Astronomy · #Advanced X-ray Imaging Techniques #Atomic physics #Compton scattering #Computational physics #Electron #Harmonics #High harmonic generation #Laser #Laser-Matter Interactions and Applications #Laser-Plasma Interactions and Diagnostics #Light scattering #Nuclear physics #Optics #Photon #Physics #Quantum mechanics #Ray #Scattering #Thomson scattering #physics.optics #physics.plasm-ph
paper · pdf · doi:10.1038/25303
published in Nature 396(6712), 653-655 (Nature Portfolio) · including 4 figures
arxiv created 1998/10/28 · openalex publication_date 1998/12/01 · arxiv updated 2009/12/01 · openalex created_date 2017/04/07 · openalex updated_date 2026/08/05
A century ago, J. J. Thomson showed that the scattering of low-intensity light by electrons was a linear process (i.e., the scattered light frequency was identical to that of the incident light) and that light's magnetic field played no role. Today, with the recent invention of ultra-high-peak-power lasers it is now possible to create a sufficient photon density to study Thomson scattering in the relativistic regime. With increasing light intensity, electrons quiver during the scattering process with increasing velocity, approaching the speed of light when the laser intensity approaches 1018 W/cm2. In this limit, the effect of light's magnetic field on electron motion should become comparable to that of its electric field, and the electron mass should increase because of the relativistic correction. Consequently, electrons in such high fields are predicted to quiver nonlinearly, moving in figure-eight patterns, rather than in straight lines, and thus to radiate photons at harmonics of the frequency of the incident laser light, with each harmonic having its own unique angular distribution. In this letter, we report the first ever direct experimental confirmation of these predictions, a topic that has previously been referred to as nonlinear Thomson scattering. Extension of these results to coherent relativistic harmonic generation may eventually lead to novel table-top x-ray sources.