Probing the transition from an uncoupled to a strong near-field coupled regime between bright and dark mode resonators in metasurfaces
Date
2014-08-27Author
Singh, Ranjan
Al-Naib, Ibraheem
Chowdhury, Dibakar Roy
Cong, Longqing
Rockstuhl, Carsten
Zhang, Weili
Metadata
Show full item recordAbstract
The coupling of multiple plasmonic resonators that sustain bright or dark modes provide intriguing spectral signatures. However, probing the onset of coupling effects while engaging the resonators with an increasing proximity has not yet been studied experimentally in detail. Nevertheless, this is of utmost importance to bridge the phenomenological understanding with the peculiarities of real-world-samples. Here, we take advantage of the ability to control spatial dimensions of THz metasurfaces deep in the sub-wavelength domain to study different regimes that occur while coupling split-ring-resonators that sustain a bright and a dark mode with increasing strength. We identify the length scales at which the resonators are uncoupled and then enter the regimes of weak, moderate, and strong coupling. It is shown that a strong coupling takes place only at distances smaller than one hundredth of the resonance wavelength. Understanding the features that emerge from such hybridization is important to take advantage of fundamental effects in metamaterials such as classical analogs of electromagnetically induced transparency, lasing spaser, near-field manipulation, and sensing with dark mode resonances.
Citation
Singh, R., Al-Naib, I., Chowdhury, D. R., Cong, L., Rockstuhl, C., & Zhang, W. (2014). Probing the transition from an uncoupled to a strong near-field coupled regime between bright and dark mode resonators in metasurfaces. Applied Physics Letters, 105(8), Article 081108. https://doi.org/10.1063/1.4893726