Design of aluminum-based nanoring arrays for realizing efficient plasmonic sensors

In this work, for the first time to our knowledge, an aluminum-based plasmonic nanoring array has been employed to present a practical approach for design of efficient optical sensors. Applying aluminum for this design benefits from cost-effectiveness, CMOS-compatibility, and ease of fabrication, while offering tunable and selective optical characteristics. Utilizing surface plasmon resonances of the proposed nanostructure, an effective refractive index sensor at visible wavelengths has been achieved. The simulation results show a high sensitivity up to 408 nm/RIU with a figure of merit of 5.88, which is comparable to those of gold-based plasmonic sensors and even outperforms some of them.