Twisted split-ring-resonator photonic metamaterial with huge optical activity

TL;DR

This paper demonstrates a novel photonic metamaterial with a twisted split-ring-resonator design that achieves large optical activity and circular dichroism, with significant rotation angles at visible frequencies.

Contribution

It introduces a specific lateral arrangement of split-ring resonators that eliminates birefringence and enhances optical activity in the visible spectrum.

Findings

Achieved about 30-degree rotation at 100 THz frequency

Eliminated linear birefringence to obtain pure optical activity

Experimental results agree with theoretical modeling

Abstract

Coupled split-ring-resonator metamaterials have previously been shown to exhibit large coupling effects, which are a prerequisite for obtaining large effective optical activity. By a suitable lateral arrangement of these building blocks, we completely eliminate linear birefringence and obtain pure optical activity and connected circular optical dichroism. Experiments at around 100-THz frequency and corresponding modeling are in good agreement. Rotation angles of about 30 degrees for 205nm sample thickness are derived.