Abstract

We demonstrate that the local resonance of metamaterials can be tuned by the effects of organic thin films under photoexcitation. Tris (8-hydroxyquinolinato) aluminum (Alq₃) layers are deposited on metamaterial/silicon hybrid structures. By varying the thickness of the Alq₃ layer on the subwavelength scale, the resonant peak of the metamaterial becomes very adjustable, due to the effect of a thin dielectric substrate. In addition, under photoexcitation all the spectral peaks of the resonance shift to higher frequencies. This originates from the reduction of the capacitive response generated inside the gaps of split-ring resonators. The adjustability of the electromagnetic spectrum may be useful for developing optical systems requiring refractive-index engineering and active optical devices.

© 2017 Optical Society of Korea

Thin-film sensing with planar terahertz metamaterials: sensitivity and limitations

John F. O’Hara, Ranjan Singh, Igal Brener, Evgenya Smirnova, Jiaguang Han, Antoinette J. Taylor, and Weili Zhang
Opt. Express 16(3) 1786-1795 (2008)

Effect of thin silicon dioxide layers on resonant frequency in infrared metamaterials

D. J. Shelton, D. W. Peters, M. B. Sinclair, I. Brener, L. K. Warne, L. I. Basilio, K. R. Coffey, and G. D. Boreman
Opt. Express 18(2) 1085-1090 (2010)

Increasing the sensitivity of terahertz split ring resonator metamaterials for dielectric sensing by localized substrate etching

K. Meng, S. J. Park, A. D. Burnett, T. Gill, C. D. Wood, M. Rosamond, L. H. Li, L. Chen, D. R. Bacon, J. R. Freeman, P. Dean, Y. H. Ahn, E. H. Linfield, A. G. Davies, and J. E. Cunningham
Opt. Express 27(16) 23164-23172 (2019)

Absorption enhancement in thin-film organic solar cells through electric and magnetic resonances in optical metamaterial

Chen Zhang, Weizhong Zhou, Shang Sun, Ningbo Yi, Qinghai Song, and Shumin Xiao
Opt. Mater. Express 5(9) 1954-1961 (2015)

Accurate and simultaneous measurement of thickness and refractive index of thermally evaporated thin organic films by surface plasmon resonance spectroscopy

T. Del Rosso, J. Edicson Hernández Sánchez, R. Dos Santos Carvalho, O. Pandoli, and M. Cremona
Opt. Express 22(16) 18914-18923 (2014)