Fabrication of circular optical structures with a 20 nm minimum feature size using nanoimprint lithography

We demonstrated the fabrication of Fresnel zone plates with a 75 nm minimum feature size and circular gratings with a 20 nm minimum linewidth in polymethyl methacrylate using nanoimprint lithography, and in metals by means of a lift-off technique. Observation of sharp Moire patterns indicated the high fidelity of nanoimprint lithography in pattern duplication. Our results showed that nanoimprint lithography is a promising technology for patterning integrated optics.