Investigation of a dual-hole structure-based broadband femtosecond nondiffracting SPP beam emitter by photoemission electron microscopy

Nondiffracting surface plasmon polariton (SPP) beam, which has unique self-healing and non-divergence properties, can be a good candidate in the next-generation on-chip devices and has attracted considerable attention. Here, a simple and broadband coupled femtosecond nondiffracting SPP beam emitter based on a dualhole structure has been demonstrated and characterized by photoemission electron microscopy (PEEM). The PEEM experiments show that, compared with the usual one-color PEEM, the two-color PEEM scheme offers a clear image of the nondiffracting SPP by effectively reducing the influence of the light-SPP interference field. As a result, the parameters of the nondiffracting SPP beam, such as the divergence angle, waist width, and propagation distance, are experimentally determined. The PEEM images of the nondiffracting SPP are well reproduced by the finite-difference time-domain (FDTD) method. This work plays a vital role in the further study of, e.g., high spatial and temporal characterization of the dynamic evolution of nondiffracting SPP beam.

Automated summary

A novel femtosecond nondiffracting surface plasmon polariton (SPP) beam emitter based on a dual-hole structure has been demonstrated and characterized using photoemission electron microscopy (PEEM). The two-color PEEM scheme offers a clear image of the nondiffracting SPP and experimentally determines the beam parameters, which are well reproduced by the finite-difference time-domain (FDTD) method. This work is important for further studying the high spatial and temporal characterization of the dynamic evolution of nondiffracting SPP beam.