Study of the jump-amplitude function in interfered surface plasmon fields: analogy with Zeeman’s catastrophe machine

We analyze the behavior of the amplitude function for surface plasmonic fields along a trajectory that crosses the bifurcation set associated with the non-linear Helmholtz equation. Our main result reveals that the amplitude function exhibits both a self-regulating behavior as well as a jump-like discontinuity, analogous to the dynamics observed in Zeeman’s catastrophe machine. This same behavior also occurs in a diffraction field emerging from an elliptical-shaped curve propagating in free space. The study is implemented on a slit-shaped curve recorded in a thin metallic film. All the physical systems under analysis have a bifurcation set with a similar geometrical structure. The jump-amplitude is observed using an interferometric system. Experimental results are shown.