Optically Active Metasurface with Non-Chiral Plasmonic Nanoantennas

Amr Shaltout, Birck Nanotechnology Center, Purdue University
Jingjing Liu, Purdue University, Birck Nanotechnology Center
V. M. Shalaev, Birck Nanotechnology Center and School of Electrical and Computer Engineering, Purdue University
Alexander V. Kildishev, Birck Nanotechnology Center, School of ECE

Abstract

We design, fabricate, and experimentally demonstrate an optically active metasurface of lambda/50 thickness that rotates linearly polarized fight by 450 over a broadband wavelength range in the near IR region. The rotation is achieved through the use of a planar array of plasmonic nanoantennas, which generates a fixed phase-shift between the left circular polarized and right circular polarized components of the incident light. Our approach is built on a new supercell metasurface design methodology: by judiciously designing the location and orientation of individual antennas in the structural supercells, we achieve an effective chiral metasurface through a collective operation of nonchiral antennas. This approach simplifies the overall structure when compared to designs with chiral antennas and also enables a chiral effect which quantitatively depends solely on the supercell geometry. This allows for greater tolerance against fabrication and temperature effects.

Discipline(s)

Nanoscience and Nanotechnology