High-performance plasmonic metasurface sensor by triangular nano-structures

The increasing need to sense different materials has caused sensors and efforts to improve their performance to receive a lot of attention in the optics field. In this report, we present a high-performance plasmonic metasurface sensor by the DGTD method that includes a two-dimensional periodic lattice of nano-triangles on a glass film and a TiN mirror. The TiN prevents light transmission from the resonators, causing a deeper reflection dip. Two resonances are observed, which offer a maximum sensitivity of about 417 nm/RIU and 735 nm/RIU, correspondingly. In this structure, augmenting the nano-triangles enhances hot spots, improving spectral response and sensitivity. Moreover, the structure maintains an almost unchanged spectral response for small angles. Overall, this sensor can be suitable for various applications such as biosensing.