Polarization insensitive plasmonic perfect absorber with coupled antisymmetric nanorod array


Aslan E. , Kaya S., Aslan E., Korkmaz S., SARAÇOĞLU Ö. G. , Turkmen M.

SENSORS AND ACTUATORS B-CHEMICAL, cilt.243, ss.617-625, 2017 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 243
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1016/j.snb.2016.12.030
  • Dergi Adı: SENSORS AND ACTUATORS B-CHEMICAL
  • Sayfa Sayıları: ss.617-625

Özet

Plasmonic perfect absorbers have a large potential for biomolecular sensing applications such as refractometric biosensing and surface enhanced spectroscopy due to their high near-field enhancement and near-unity absorption capabilities. Despite these properties, novel plasmonic perfect absorbers with additional features are highly needed for real-world sensing applications. In this context, we present the design, characterization and experimental realization of a subwavelength plasmonic perfect absorber array with crucial properties including the dual-band absorption, high near-field enhancement with a large number of hot-spots, mass-production compatible design, high sensitivity, and polarization independency for both narrow and wide resonance bands. In order to investigate the spectral characteristics and to obtain a fine-tuning mechanism, we perform several numerical analyses by using finite difference time domain method. We also investigate the charge and current density distributions at the corresponding resonances. It is observed that the physical origin of the dual-band behavior is based on the dipolar plasmonic resonance of the horizontal nanorods and the plasmonic coupling mechanism of the structure. Furthermore, we investigate the sensing performance of the proposed device by calculating the refractive index sensitivity and figure-of-merit for the resonant modes by embedding it into different cladding media with various refractive indices. Finally, in order to demonstrate the potential of the proposed plasmonic perfect absorber for surface enhanced infrared absorption spectroscopy, we simulate the detection of carbonyl v(C=0) stretching mode of a conformal poly(methyl methacrylate) layer. Due to its highly desired properties, the proposed device can be a good candidate for biomolecular sensing applications and also the results of our investigation can be useful for the further designs of plasmonic based sensors. (C) 2016 Elsevier B.V. All rights reserved.