We demonstrate digital plasmonic holography for direct in-plane imaging with propagating surface-plasmon waves. Imaging with surface plasmons suffers from the lack of simple in-plane lenses and mirrors. Lens-less digital holography techniques, however, rely on digitally decoding an interference pattern between a reference wave and an object wave. With far-field diffractive optics, this decoding scheme provides a full recording, i.e., a hologram, of the amplitude and phase of the object wave, giving three-dimensional information from a two-dimensional recording. For plasmonics, only a one-dimensional recording is needed, and both the phase and amplitude of the propagating plasmons can be extracted for high-resolution in-plane imaging. Here, we demonstrate lens-less, point-source digital plasmonic holography using two methods to record the plasmonic holograms: a dual-probe near-field scanning optical microscope and lithographically defined circular fluorescent screens. The point-source geometry gives in-plane magnification, allowing for high-resolution imaging with relatively lower-resolution microscope objectives. These results pave the way for a new form of in-plane plasmonic imaging, gathering the full complex wave, without the need for plasmonic mirrors or lenses.
Physics and Engineering
Light: Science and Applications
Nelson, Joseph W.; Knefelkamp, Greta R.; Brolo, Alexandre G.; and Lindquist, Nathan C., "Digital plasmonic holography" (2018). Physics and Engineering Faculty Publications. 10.
Student authors: Joseph Nelson, Greta Knefelkamp (Physics and Engineering)
Permission to deposit granted by Creative Commons Attribution 4.0 International License
Article originally published in Nelson, J.W., Knefelkamp, G.R., Brolo, A.G. et al. Digital plasmonic holography. Light Sci Appl 7, 52 (2018). https://doi.org/10.1038/s41377-018-0049-2