Numerical simulations of induced spatial incoherence laser light self-focusing

Journal Article · Fri Dec 01 00:00:00 EST 1989 · Physics of Fluids B: Plasma Physics; (USA)

DOI:https://doi.org/10.1063/1.859179· OSTI ID:5146598

Rankin, R; Capjack, C E; James, C R ^[1]

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1. 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), Vol. 1:12; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
LASER-PRODUCED PLASMA
NONLINEAR PROBLEMS
AMPLITUDES
FOCUSING
HYDRODYNAMICS
LASER RADIATION
NUMERICAL SOLUTION
PLASMA DENSITY
SIMULATION
ELECTROMAGNETIC RADIATION
FLUID MECHANICS
MECHANICS
PLASMA
RADIATIONS
700108* - Fusion Energy- Plasma Research- Wave Phenomena