Nonlinear laser focusing using a conical guide and generation of energetic ions.
Using conventional methods, a laser pulse can be focused down to around 6-8 microm, but further reduction of the spot size has proven to be difficult. Here it is shown by particle-in-cell simulation that with a hollow cone an intense laser pulse can be reduced to a tiny, highly localized, spot of around 1 microm radius, accompanied by much enhanced light intensity. The pulse shaping and focusing effect is due to a nonlinear laser-plasma interaction on the inner surface of the cone. When a thin foil is attached to the tip of the cone, the cone-focused light pulse compresses and accelerates the ions in its path and can punch through the thin target, creating highly localized energetic ion bunches of high density.
Cao
Lihua
L
Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100088, China.
Yu
Wei
W
Yu
M Y
MY
Xu
Han
H
He
X T
XT
Gu
Yuqiu
Y
Liu
Zhanjun
Z
Li
Jinghong
J
Zheng
Chunyang
C