Numerical simulations of induced spatial incoherence laser light self-focusing
- Department of Electrical Engineering, University of Alberta, Edmonton, Alberta T6G 2G7, Canada (CA)
The effect of induced spatial incoherence (ISI) on laser light self-focusing is investigated using a two-dimensional Eulerian hydrodynamic plasma simulation code. In homogeneous low-density plasmas (one-tenth of the critical density for radiation of wavelength {lambda}{sub {ital L}}=0.25 {mu}m) it is found that ISI can effectively eliminate thermal and ponderomotive self-focusing for a wide range of intensities. In plasma containing an initial linear gradient in density, strong self-focusing occurs when the maximum intensity in the incident light {ital I}{sub 0} (where {ital I}{sub 0} represents the intensity that would be achieved for a perfectly coherent beam) is allowed to approach 10{sup 17} W cm{sup {minus}2}. At lower intensities, {ital I}{sub 0}{similar to}10{sup 16} W cm{sup {minus}2}, thermal self-focusing is eliminated and ponderomotive self-focusing is significantly reduced. The dwell time of the filamented light varies from the laser light coherence time to a few tens of picoseconds.
- OSTI ID:
- 5146598
- Journal Information:
- Physics of Fluids B: Plasma Physics; (USA), Journal Name: Physics of Fluids B: Plasma Physics; (USA) Vol. 1:12; ISSN 0899-8221; ISSN PFBPE
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
AMPLITUDES
ELECTROMAGNETIC RADIATION
FLUID MECHANICS
FOCUSING
HYDRODYNAMICS
LASER RADIATION
LASER-PRODUCED PLASMA
MECHANICS
NONLINEAR PROBLEMS
NUMERICAL SOLUTION
PLASMA
PLASMA DENSITY
RADIATIONS
SIMULATION