Tunable focus and multiple plasmonic bottles from the superposition of half Pearcey plasmons

In this paper we utilize the half Pearcey function as a means to describe a surface plasmon, the half Pearcey plasmon. The abrupt autofocusing and self-healing properties from the superposition of the half Pearcey plasmon are observed and discussed. The tunable focal intensity covers three orders of magnitude and the autofocusing property can be maintained with the potential well. Additionally, with the $\ensuremath{\pi}$ phase offset, we construct multiple plasmonic bottles with the chirp factor; both the bottle structure and propagating direction are adjustable. The focusing properties of the plasmon under the chirp depend on the spatial spectrum separation, resulting in the construction of plasmonic bottles with different positions and sizes. The validity of our results is confirmed by finite-difference time-domain numerical simulations. Our findings may provide potential for spectral enhancement, nanoscale plasmonic devices, and plasmonic trapping.