Enhanced broadband absorption in gold by plasmonic tapered coaxial holes
2014 (English)In: Optics Express, ISSN 1094-4087, Vol. 22, no 26, 32233-32244 p.Article in journal (Refereed) Published
Gold absorbers based on plasmonic tapered coaxial holes (PTCHs) are demonstrated theoretically and experimentally. An average absorption of over 0.93 is obtained theoretically in a broad wavelength range from 300 nm to 900 nm without polarization sensitivity due to the structural symmetry. Strong scattering of the incident light by the tapered coaxial holes is the main reason for the high absorption in the short wavelength range below about 550 nm, while gap surface plasmon polaritons propagating along the taper dominate the resonance-induced high absorption in the long wavelength range. Combining two PTCHs with different structural parameters can further enhance the absorption and thus increase the spectral bandwidth, which is verified by a sample fabricated by focused ion beam milling. This design is promising to be extended to other metals to realize effective and efficient light harvesting and absorption.
Place, publisher, year, edition, pages
2014. Vol. 22, no 26, 32233-32244 p.
Electromagnetic wave polarization, Gold, Ion beams, Broadband absorption, Focused ion beam milling, Gap surface plasmons, Long-wavelength-range, Polarization sensitivity, Spectral bandwidth, Structural parameter, Structural symmetry
Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-159372DOI: 10.1364/OE.22.032233ISI: 000347179300060ScopusID: 2-s2.0-84920124265OAI: oai:DiVA.org:kth-159372DiVA: diva2:784796
QC 201501302015-01-302015-01-292015-01-30Bibliographically approved