Time-dependent phase conjugation in plasmas: Numerical results and interpretation | CU Experts

The salient features of time-dependent phase conjugation and four-wave mixing in a plasma are summarized and developed numerically in an extension of the work of Goldman and Williams [Phys. Fluids B 3, 751 (1991)]. It is shown that plasma nonuniformity can reduce the decay time of a conjugate wave responding to a delta-function signal without significant reduction in the maximum amplitude of the phase-conjugate wave. A phase-conjugating nonuniform plasma may therefore offer advantages over other media in the tracking or self-targeting of moving objects. The temporal approach to steady-state of an amplified phase-conjugate wave is found numerically for the case of resonant four-wave mixing driven by pumps of unequal intensity; the temporal response above threshold for absolute instability is also studied. Related absolute instabilities pumped by Langmuir waves are briefly described. Effects of nonuniformity are considered in connection with amplified phase conjugation.

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