Nonlinear Optics of Free Electrons

We report the investigation of the wave-mixing process with two multiple-cycle pulses having incommensurate frequencies (at 1400 nm and 800 nm). With a collinear and non-collinear configuration of the two beams, a different extreme ultraviolet (XUV) mixing field can be created at low intensity of the 800 nm field. For a high intensity of the second laser pulse we are able to amplify the XUV radiation. We show that the dynamics of the free electrons can be revealed from the frequency mixing process.

Download Full-text

Relativistic Nonlinear Optics of Free Electrons in Laser-Driven Plasmas

Nonlinear Optics: Materials, Fundamentals and Applications ◽

10.1364/nlo.2000.we2 ◽

2000 ◽

Author(s):

Donald Umstadter

Keyword(s):

Nonlinear Optics ◽

Free Electrons

Download Full-text

Dynamic studies of silicide-mediated crystallization of amorphous silicon

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100131395 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1352-1353

Author(s):

C. Hayzelden ◽

J. L. Batstone

Keyword(s):

Ion Implantation ◽

Solid Phase ◽

Metallic Phase ◽

Single Crystal Substrate ◽

Free Electrons ◽

Melt Temperature ◽

Transmission Electron ◽

Crystal Substrate ◽

High Resolution Tem

Epitaxial reordering of amorphous Si(a-Si) on an underlying single-crystal substrate occurs well below the melt temperature by the process of solid phase epitaxial growth (SPEG). Growth of crystalline Si(c-Si) is known to be enhanced by the presence of small amounts of a metallic phase, presumably due to an interaction of the free electrons of the metal with the covalent Si bonds near the growing interface. Ion implantation of Ni was shown to lower the crystallization temperature of an a-Si thin film by approximately 200°C. Using in situ transmission electron microscopy (TEM), precipitates of NiSi2 formed within the a-Si film during annealing, were observed to migrate, leaving a trail of epitaxial c-Si. High resolution TEM revealed an epitaxial NiSi2/Si(l11) interface which was Type A. We discuss here the enhanced nucleation of c-Si and subsequent silicide-mediated SPEG of Ni-implanted a-Si.Thin films of a-Si, 950 Å thick, were deposited onto Si(100) wafers capped with 1000Å of a-SiO2. Ion implantation produced sharply peaked Ni concentrations of 4×l020 and 2×l021 ions cm−3, in the center of the films.

Download Full-text