Nanoscale TiO2 dielectric resonator absorbers

Chengjun Zou, Philipp Gutruf, Withawat Withayachumnankul, Longfang Zou, Madhu Bhaskaran, Sharath Sriram, Christophe Fumeaux

Research output: Contribution to journalArticle

29 Scopus citations

Abstract

We demonstrate a narrow-band plasmonic absorber based on a uniform array of nanoscale cylindrical dielectric resonators (DRs) on a metallic substrate at visible frequencies. Under a normally incident plane-wave excitation, the DRs resonate in their horizontal magnetic dipolar mode, which can be seen as localized plasmonic hot spots. Such a localized resonance also couples incident waves into surface plasmon polaritons (SPPs) bidirectionally, and perfect absorption is achieved by creating SPP standing waves. The simulation shows perfect absorption at 633 nm and 1.8% relative bandwidth with >90% absorption, while the measurement demonstrates maximum absorption of 90% at 636 nm. Both simulation and measurement results are analyzed with coupled mode theory. An additional numerical study elaborates on the dependence of absorption on the resonator size, period, and incidence angle.

Original languageEnglish (US)
Pages (from-to)3391-3394
Number of pages4
JournalOptics letters
Volume41
Issue number15
DOIs
StatePublished - Aug 1 2016
Externally publishedYes

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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    Zou, C., Gutruf, P., Withayachumnankul, W., Zou, L., Bhaskaran, M., Sriram, S., & Fumeaux, C. (2016). Nanoscale TiO2 dielectric resonator absorbers. Optics letters, 41(15), 3391-3394. https://doi.org/10.1364/OL.41.003391