Low Loss Non-plasmonic Nanoantennas for Surface-Enhanced Spectroscopy and Fluorescence

P. ALBELLA; M. CALDAROLA; E. CORTÉS; M. RAHMANI; T. ROSCHUK; G. GRINBLAT; A.V. BRAGAS; S. A. MAIER

Simposio; Progress In Electromagnetics Research Symposium; 2015

Plasmonic structures enable control and manipulation of light at the nanoscale,allowing for strong enhancements of the electric field for interactions with molecules and materials in their vicinity [1]. Unfortunately, these large enhancements come with the cost of high optical losses due to absorption in the metal, severely limiting some real-world applications. Specifically, localized heating strongly limits the total power that can be delivered to a nanoscale field hot spot before the nanostructure melts and reshapes, affecting their suitability for applications such as lighting and photonic modulation [2]. Moreover, the emission properties of molecules placed near the nanoantennas, can also be modified by this local heating [3]. Here we present a method to overcome these heating issues via the realization of a novel nanophotonic platform basedon the low absorption dielectric nanostructures (silicon, germanium or gallium phosphide) that we theoretically proposed in [4, 5] to form efficient non-plasmonic nanoantennas with ultra-low light-into-heat conversion. We show that silicon-based nanoantennas produce both high surface enhanced fluorescence (SEF) and good surface enhanced Raman scattering (SERS), while at the same time producing a negligible temperature increase in their hot spots and surroundingenvironments compared to gold [6].REFERENCES [1] Bharadwaj, P., B. Deutsch, and L. Novotny, Optical antennas, Advances in Optics and Photonics, Vol. 1, No. 3, 438, 2009. [2] Kuhlicke, A., S. Schietinger, C. Matyssek, K. Busch, and O. Benson, In situ observation of plasmon tuning in a single gold nanoparticle during controlled melting, Nano Letters, Vol. 13, No. 5, 2041-2046, 2013. [3] Mahmoudi, M., et al., Variation of protein corona composition of gold nanoparticles following plasmonic heating, Nano Letters, Vol. 14, No. 1, 6-12, 2013. [4] Albella, P., M. A. Poyli, M. K. Schmidt, S. A. Maier, F. Moreno, J. J. Saenz, and J. Aizpurua, Low-loss electric and magnetic field-enhanced spectroscopy with subwavelength silicon dimers, Journal of Physical Chemistry C, Vol. 117, 13573-13584, 2013. [5] Albella, P., R. Alcaraz de la Osa, F. Moreno, and S. A. Maier, Electric and magnetic field enhancement with ultralow heat radiation dielectric nanoantennas: Considerations for surfaceenhanced spectroscopies, ACS Photonics, Vol. 1, No. 6, 524-529, 2014. [6] Caldarola, M., P. Albella, E. Cortes, M. Rahmani, T. Roschuk, G. Grinblat, A. V. Bragas, and S. A. Maier, Non-plasmonic nanoantennas for surface enhanced spectroscopies with ultra-low heat conversion (Submitted).