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This content will become publicly available on January 25, 2019

Title: Correlating Nanoscopic Energy Transfer and Far-Field Emission to Unravel Lasing Dynamics in Plasmonic Nanocavity Arrays

Excited-state interactions between nanoscale cavities and photoactive molecules are critical in plasmonic nanolasing, although the underlying details are less-resolved. This paper reports direct visualization of the energy-transfer dynamics between two-dimensional arrays of plasmonic gold bowtie nanocavities and dye molecules. Transient absorption microscopy measurements of single bowties within the array surrounded by gain molecules showed fast excited-state quenching (2.6 ± 1 ps) characteristic of individual nanocavities. Upon optical pumping at powers above threshold, lasing action emerged depending on the spacing of the array. By correlating ultrafast microscopy and far-field light emission characteristics, we found that bowtie nanoparticles acted as isolated cavities when the diffractive modes of the array did not couple to the plasmonic gap mode. These results demonstrate how ultrafast microscopy can provide insight into energy relaxation pathways and, specifically, how nanocavities in arrays can show single-unit nanolaser properties.
ORCiD logo [1] ;  [2] ; ORCiD logo [3] ; ORCiD logo [2] ; ORCiD logo [4]
  1. Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry
  2. Purdue Univ., West Lafayette, IN (United States). Dept. of Chemistry
  3. Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering
  4. Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Nano Letters
Additional Journal Information:
Journal Volume: 18; Journal Issue: 2; Journal ID: ISSN 1530-6984
American Chemical Society
Research Org:
Purdue Univ., West Lafayette, IN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF)
Country of Publication:
United States
14 SOLAR ENERGY; 77 NANOSCIENCE AND NANOTECHNOLOGY; Localized surface plasmons; metal nanoparticle arrays; plasmon lasing; transient absorption microscopy; lattice plasmons
OSTI Identifier: