Plasmonic versus All-Dielectric Nanoantennas for Refractometric Sensing: A Direct Comparison

Abstract

In comparison to nanoplasmonic structures, resonant high-index dielectric nanoantennas hold several advantages that may benefit nanophotonic applications, including CMOS compatibility and low ohmic losses. One such application area might be label-free refractometric sensing, where changes in individual antenna resonance properties are used to quantify changes in the surrounding refractive index, for example, due to biomolecular binding. Here, we analyze and compare the sensing performance of silicon and gold nanodisks using a common and unbiased testing framework. We find that the all-dielectric system is fully capable of effectively monitoring small changes in bulk refractive index and biomolecular coverage, but the sensitivity is five to ten times lower than the plasmonic counterpart. However, this drawback is partly compensated for by a more linear response to adsorbate layer thickness changes and an approximately four times smaller susceptibility to photothermal heating. Finally, dielectric sensors may show promise if certain strategies are employed to improve their performance, which could thus bridge the gap between the two systems.

Tuning the exponential sensitivity of a bound-state-in-continuum optical sensor

“…of the system, it is worth to mention that the behavior of the resonance shift as a function of the layer thickness is profoundly different from that of an isolated dielectric nanoparticle in which the size effect rules the energy shift [41]. In case of the BIC, the mode behavior is collective and the coupling among unit cells determines the existence of the mode itself.…”

Nanostructured Organic/Hybrid Materials and Components in Miniaturized Optical and Chemical Sensors

“…Generally speaking, photonic systems have a much better-defined spectral response that can be finely tailored and is intrinsically stable and robust. On the other side, plasmonic systems offer a superior performance in terms of field confinement and enhancement, combined with the drawback of relatively large losses and a much broader spectral response [88]. Up to now, even considering that sensitivity is also depending on the chosen optical parameter (shift of spectrum, polarization, phase, intensity, in reflectance, transmittance and fluorescence mode), field enhancement remains the main factor affecting the final optical detection performance.…”

Broadened Angle-Insensitive Near-Perfect Absorber Based on Mie Resonances in Amorphous Silicon Metasurface

“…Metasurfaces are artificial planar material composed of spatially arranged subwavelength structures, which exhibit remarkable flexibility in manipulating the properties of light at an optically thin interface [1][2][3]. Perfect absorbers based on metasurfaces for energy collection and accumulation have been widely researched, which are promising in applications of light harvesting [4][5][6][7][8], optical isolation [9,10] and so on. Dielectric nanostructure metasurfaces, holding advantages including nonradiative loss [11][12][13], resonant enhancement of both electric and magnetic field [14][15][16][17][18][19], attract much attention in research of high absorption induced by the Mie dipole resonances [20][21][22][23].…”