Nano sensing based on transparency effect in planar metamaterial

A planar metamaterial, consisting of double-slot cavities in a unit cell, has been investigated in detail. The results indicate that the interaction between two bright modes also leads to the transparency effect. Meanwhile, the transparency window can be adjusted by changing the length of slot cavity and the distance between two slot cavities. Finally, it is demonstrated that the planar metamaterial design may serve as a highly efficient sensor in near-infrared. The sensitivity is as high as 520 nm/RIU, and the FOM is up to 24.83. The planar metamaterial has the advantages of simple and compact structure, easy fabrication, which will greatly benefit the optical switch, nano plasmonic sensor in highly integrated optical circuits.