Highly Sensitive and Polarization Selective Au Serrate Nanogratings Fabricated by Nanoimprint Lithography

In this work, we propose a low cost and high throughput novel asymmetric nanogratings fabricated by nanoimprint lithography. The proposed structure is 160 nm linewidth, 600 nm pitch and 1 cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> area. The proposed Au serrate nanogratings could induce surface charges under both TE and TM polarized light due to the asymmetric serrates. The measured sensitivity of serrate nanogratings is 561 nm/RIU. In addition, the resonance peak could be tunable by fabricating different nanostructures with the same nanoimprint mold.