  We report on the first experimental demonstration that the microstructure
based on a dielectric cuboid combined to a thin metal film can act as an
efficient plasmonic lens allowing focusing surface plasmons in a subwavelength
scale. By means of numerical simulation of surface plasmon-polariton (SPP)
field intensity distributions in the microstructure, we observe a low
divergence of plasmonic photonic jet (PPJ) and high intensity subwavelength
spots at the communication wavelength of 1530 nm. Then we fabricate an
experimental sample of the microstructure and study the SSP field intensity
distributions using the amplitude and phase-resolved scanning near-field
optical microscopy and demonstrate the experimental observation of the PPJ
effect for the SSP waves. Such novel and simple platform can provide new
pathways for plasmonics, high-resolution imaging, biophotonics as well as
optical data storage.
