Multiperiodic nanohole array for high precision sensing

In this article, we present a multiperiodic nanohole array structure for improved sensing. The structure consists a series of rows of nanoholes, each having a different period in an ascending order. A monochromatic source illuminates the structure, and a resonance condition is met for the row having a momentum matching Bloch wave, which leads to extraordinary optical transmission. With this new plasmonic structure, the sensing signal can be retrieved using the spatial position of the transmissionmaxima. This setup requires a simple optical setup whileachieving increased resolution and accuracy. A resolutionof 4.6 × 10−6 refractive index units is achieved, which iscomparable to surface plasmon resonance system based on the Kretchmann configuration.

Uncontrolled Keywords

nanomaterials; optical sensors; subwavelength structure; surface waves