We deploy two-dimensional nano-hole arrays as resonant surface plasmon polariton (SPP) couplers that enable counter-propagation and interference-free imaging of SPP wave-packets. We monitor the spatiotemporal evolution of the resulting SPPs using two-color photoemission electron microscopy (PEEM). The measurements track the electric field envelope of the SPP in real space and time and enable direct characterization of their spatiotemporal properties in a regime where the SPP wave-packet is the principle observable. We provide an analysis of the observables for both the co- and counter-propagating directions via SPP trajectories that are recorded in tandem. Our results highlight the advantages of isolating SPPs through counter-propagation, where field-SPP interactions are suppressed.
Published: March 31, 2022
Citation
Crampton K.T., A.G. Joly, and P.Z. El-Khoury. 2019.Direct Visualization of Counter-Propagating Surface Plasmons in Real Space-Time.The Journal of Physical Chemistry Letters 10, no. 19:5694-5699.PNNL-SA-146664.doi:10.1021/acs.jpclett.9b02151