naa a22 4500 510817521 CHVBK 20180411083515.0 cr unu---uuuuu 180411e20130601xx s 000 0 eng 10.1007/s11468-013-9491-4 doi (NATIONALLICENCE)springer-10.1007/s11468-013-9491-4 Spatial Distribution of Optical Near-Fields in Plasmonic Gold Sphere Segment Voids [Elektronische Daten] [M. Schmidt, N. Tognalli, M. Otte, M. Alonso, B. Sepúlveda, A. Fainstein, A. Goñi] We present a comprehensive experimental and computational study on the electromagnetic field distribution in sphere segment void arrays. Surface plasmon polaritons can be excited in these void arrays, resulting in greatly enhanced electromagnetic fields. With the scanning near-field optical microscope (SNOM) we are able to measure the electromagnetic field distribution at the sample surface. For this purpose, an array of relatively large voids with a sphere diameter of 900 nm was fabricated, allowing for an easy access of the scanning glass-fibre tip and yielding very detailed scans. Complementary, finite-difference time-domain (FDTD) calculations on a complete void array have been performed and compared with the SNOM intensity maps and experimental reflectivity data. We show in a direct way both the existence of extended and localised modes in the Au void array for three different void depths. We also show and discuss the changes that the modes undergo for the different void depths and excitation wavelengths. Moreover, since the simulations were performed for two different void geometries, one containing perfectly spherical void surfaces and another more realistic one, which considers the presence of interstitial wall holes and other imperfections, as observed in scanning electron micrographs, we were able to determine by comparison with the experiment under which conditions an array of idealised sphere segment voids is a meaningful model. This demonstrates that both SNOM and FDTD simulations are powerful tools for understanding the plasmonic response of metallic nanostructures, thus enabling, for instance, a design for applications in ultra-sensitive optical detection. Springer Science+Business Media New York, 2013 Scanning near-field optical microscope nationallicence Plasmonic nanostructure nationallicence Finite-difference time-domain calculation nationallicence Schmidt M. Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193, Bellaterra, Catalunya, Spain aut Tognalli N. Research Center on Nanoscience and Nanotechnology (CIN2-CSIC) & CIBER-BBN, 08193, Bellaterra, Barcelona, Spain aut Otte M. Research Center on Nanoscience and Nanotechnology (CIN2-CSIC) & CIBER-BBN, 08193, Bellaterra, Barcelona, Spain aut Alonso M. Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193, Bellaterra, Catalunya, Spain aut Sepúlveda B. Research Center on Nanoscience and Nanotechnology (CIN2-CSIC) & CIBER-BBN, 08193, Bellaterra, Barcelona, Spain aut Fainstein A. Centro Atómico Bariloche-Instituto Balseiro, C.N.E.A., 8400, San Carlos de Bariloche, Río Negro, Argentina aut Goñi A. Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193, Bellaterra, Catalunya, Spain aut Plasmonics Springer US; http://www.springer-ny.com 8/2(2013-06-01), 921-930 1557-1955 8:2<921 2013 8 11468 https://doi.org/10.1007/s11468-013-9491-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11468-013-9491-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Schmidt M. Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193, Bellaterra, Catalunya, Spain aut NATIONALLICENCE 700 1- Tognalli N. Research Center on Nanoscience and Nanotechnology (CIN2-CSIC) & CIBER-BBN, 08193, Bellaterra, Barcelona, Spain aut NATIONALLICENCE 700 1- Otte M. Research Center on Nanoscience and Nanotechnology (CIN2-CSIC) & CIBER-BBN, 08193, Bellaterra, Barcelona, Spain aut NATIONALLICENCE 700 1- Alonso M. Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193, Bellaterra, Catalunya, Spain aut NATIONALLICENCE 700 1- Sepúlveda B. Research Center on Nanoscience and Nanotechnology (CIN2-CSIC) & CIBER-BBN, 08193, Bellaterra, Barcelona, Spain aut NATIONALLICENCE 700 1- Fainstein A. Centro Atómico Bariloche-Instituto Balseiro, C.N.E.A., 8400, San Carlos de Bariloche, Río Negro, Argentina aut NATIONALLICENCE 700 1- Goñi A. Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193, Bellaterra, Catalunya, Spain aut NATIONALLICENCE 773 0- Plasmonics Springer US; http://www.springer-ny.com 8/2(2013-06-01), 921-930 1557-1955 8:2<921 2013 8 11468 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer