Bispectrum and nonlinear wave coupling

The relationship between nonlinear wave coupling and the properties of the bispectrum are investigated for the case of three-wave coupling. In particular, the dependence of the phase of the bispectrum, the direction of power flow between modes, and the sign of the skewness parameter, on the nonlinear amplitude variation and coupling coefficient, is analytically investigated and found to be in good agreement with experimental observations.