Resonant electromagnetic wave mixing in a dusty plasma

Wave mixing resulting from the resonance of electromagnetic waves with ion acoustic waves modified by dust charge fluctuations is investigated. The corresponding nonlinear susceptibilities are derived and applied to the study of phase conjugation by four-wave mixing. It is shown that dust charge fluctuations can lead to a filling-up of the resonance-induced splitting of the phase-conjugate reflectivity, making the latter a useful tool for the diagnostics of dusty plasmas.