OPTICAL ELEMENTS INCLUDING PSUEDORANDOM-SHAPED META-ATOMS

The disclosure describes optical elements including pseudorandom-shaped meta-atoms as well as related methods of manufacture. In some implementations, a method includes patterning a resist layer to form a pattern of features in the resist layer. The resist layer is disposed on a substrate that includes an optical sublayer disposed on a support. The substrate further includes a hard mask sublayer disposed on the optical sublayer. The method includes performing a first oxygen plasma etch to impart a pseudorandom shape to the features in the resist layer, and subsequently performing a plurality of etching operations to cause the pseudorandom-shaped features to be transferred into the optical sublayer of the substrate.