Interaction of the Lissajous singularity and singular Lissajous line passing thr

The interaction of the Lissajous singularity and singular Lissajous line in the presence of an astigmatic lens is studied. It is found that the singular Lissajous line is usually unstable, and disappears after passage through the lens. The creation and annihilation of one or two Lissajous singularit