Parametric interactions when resonator reactances are varied in antiphase

The letter considers a situation where both reactances of a resonator are pumped in exact antiphase. While a previous mode of pumping, where the reactances are pumped in unison, has been shown incapable of yielding parametric excitations, the present mode exhibits several possible interactions. Some of the interactions are similar to those in common parametric systems; other interactions seem unfamiliar and related to an aperiodic mode of pumping. The results, and especially those concerning the latter interaction, appear relevant to practical microwave, acoustic and optical systems, and may lead to new applications.