Abstract

In this work, we have designed a photonic-metamaterial based broadband circular polarizer using $N=4$ phase-lagged aluminum single helices arranged in a square array as a unit cell. The effect of phase differences between the helices in an array on the optical performance of the structure is studied, and a comparative study is done with that of multi-intertwined helices. It is observed that the proposed metamaterial structure shows circular polarization sensitivity over a broad optical wavelength range ($\approx 450–900\mathrm{nm}$), with improved optical performance in average extinction ratio and broad positive circular dichroism in comparison to multiple intertwined helices. The induced phase lag between the helices in a square-array based unit cell reduces the linear birefringence and leads to the recovery of circular space symmetry in the structure.

© 2015 Optical Society of America

On metamaterial circular polarizers based on metal N-helices

Johannes Kaschke, Justyna K. Gansel, and Martin Wegener
Opt. Express 20(23) 26012-26020 (2012)

Dispersion-free broadband optical polarization rotation based on helix photonic metamaterials

Yu-Ray Li and Yu-Chueh Hung
Opt. Express 23(13) 16772-16781 (2015)

Tapered N-helical metamaterials with three-fold rotational symmetry as improved circular polarizers

Johannes Kaschke, Mark Blome, Sven Burger, and Martin Wegener
Opt. Express 22(17) 19936-19946 (2014)

Higher extinction ratio circular polarizers with hetero-structured double-helical metamaterials

Yang Yu, Zhenyu Yang, Shengxi Li, and Ming Zhao
Opt. Express 19(11) 10886-10894 (2011)

Dual circular polarization gaps in helix photonic metamaterials

Tzu-Hung Kao, Lung-Yu Chang Chien, and Yu-Chueh Hung
Opt. Express 23(19) 24416-24425 (2015)