Extraordinary Transmission Characteristics of Subwavelength Nanoholes with Rectangular Lattice
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We investigate the extraordinary optical transmission (EOT) properties of nanohole arrays with a rectangular lattice for label-free refractive index sensing applications. We show that the deviation within the periodicities along the two axes at the nanohole plane leads to more advantageous spectral quality of EOT signal compared to the conventional square lattice geometries. We introduce a way to further improve the sensitivity of the aperture system by carefully choosing the periodicities. We introduce nanohole arrays with a rectangular lattice supporting EOT signals with larger figure-of-merit values as well as enabling much stronger light transmission. We also model a nanohole system covered with a thin dielectric layer, mimicking biomolecules captured on the gold surface, in order to show its biosensing capability. We also show that certain deviation amounts between periodicities create spectral splitting within the EOT signal leading to larger spectral shifts in the presence of a thin dielectric film.
KeywordsPlasmonics Nanoholes Extraordinary optical transmission Rectangular lattice Label-free biosensing
J. Petráček acknowledges the support of the Ministry of Education, Youth, and Sports of the Czech Republic (project LD14008).
- 11.Coskun AF, Cetin AE, Galarreta BC, Alvarez DA, Altug H, Ozcan A (2014) Lensfree optofluidic plasmonic sensor for real-time and label-free monitoring of molecular binding events over a wide field-of-view. Sci Rep 4:1–7Google Scholar
- 22.Ekşioğlu Y, Cetin AE, Petráček J (2016) Optical response of plasmonic nanohole arrays: comparison of square and hexagonal lattices. Plasmonics 11:851–856Google Scholar
- 25.Hanes WM (2015) CRC handbook of chemistry and physics. CRC, Boca RatonGoogle Scholar