Electrical & Computer Engineering, Department of


Date of this Version



Published in APPLIED PHYSICS LETTERS 91, 081501 2007. © 2007 American Institute of Physics. Used by permission.


The spatial confinement effects in laser-induced breakdown of aluminum (A1) targets in air have been investigated both by optical emission spectroscopy and fast photography. A KrF excimer laser was used to produce plasmas from Al targets in air. Al atomic emission lines show an obvious enhancement in the emission intensity when a pair of Al-plate walls were placed to spatially confine the plasma plumes. Images of the Al plasma plumes showed that the plasma plumes evolved into a torus shape and were compressed in the Al walls. The mechanism for the confinement effects was discussed using shock wave theory.