Pearcey Plasmon: An Autofocusing Surface Wave

In this article, we present a new kind of autofocusing surface plasmonic wave: the Pearcey plasmon. The result shows that the Pearcey plasmon evolves at the silver-air interface in the form of two-dimensional Pearcey plasmon function. And the Pearcey plasmon can be decomposed into two Airy-like plasmons bending in the opposite direction after autofocusing, which leads to dual self-bending behavior of a Pearcey plasmon. We demonstrate the interference patterns of two Airy-like plasmons and find that the self-focusing focus position during propagation is controllable. Also, we find that when a single variable is controlled, both the long wavelength and the large truncation coefficient will reduce the maximum intensity as well as the focal length of the Pearcey plasmon. Furthermore, taking the intensity reduced to 50% of the maximum intensity as a reference, we find that the divergence distance of a Pearcey plasmon is approximately 65 times longer than that of a Gaussian plasmon, which means that under the same intensity, a Pearcey plasmon propagates much farther than a Gaussian plasmon.