Tomographic imaging of the photonic environment of plasmonic nanoparticles

作者：Hoerl Anton; Haberfehlner Georg; Truegler Andreas; Schmidt Franz Philipp; Hohenester Ulrich^*; Kothleitner Gerald

来源：Nature Communications, 2017, 8(1): 37.

DOI：10.1038/s41467-017-00051-3

The photonic local density of states (LDOS) governs the enhancement of light-matter interaction at the nanoscale, but despite its importance for nanophotonics and plasmonics experimental local density of states imaging remains extremely challenging. Here we introduce a tomography scheme based on electron microscopy that allows retrieval of the three-dimensional local density of states of plasmonic nanoparticles with nanometre spatial and sub-eV energy resolution. From conventional electron tomography experiments we obtain the three-dimensional morphology of the nanostructure, and use this information to compute an expansion basis for the photonic environment. The expansion coefficients are obtained through solution of an inverse problem using as input electron-energy loss spectroscopy images. We demonstrate the applicability of our scheme for silver nanocuboids and coupled nanodisks, and resolve local density of states enhancements with extreme sub-wavelength dimensions in hot spots located at roughness features or in gaps of coupled nanoparticles.

• 出版日期2017-6-26