Irradiation of a planar solid by an intense laser pulse leads to fast electron acceleration and hard x-ray production. We have investigated whether this high field production of fast electrons can be controlled by introducing dielectric spheres of well-defined size on the target surface. We find that the presence of spheres with a diameter slightly larger than half the laser wavelength leads to Mie enhancements of the laser field which, accompanied by multipass stochastic heating of the electrons, leads to significantly enhanced hard x-ray yield and temperature.
© 2007 American Physical Society
H. A. Sumeruk, S. Kneip, D. R. Symes, I. V. Churina, A. V. Belolipetski, T. D. Donnelly, and T. Ditmire, "Control of Strong-Laser-Field Coupling to Electrons in Solid Targets with Wavelength-Scale Spheres," Phys. Rev. Lett., 98, 045001 (2007). doi: 10.1103/PhysRevLett.98.045001