We report extremely strong optical activity and circular dichroism exhibited by subwavelength arrays of four-start-screw holes fabricated with single-pass focused ion beam milling of freely suspended silver films. Having the fourth order rotational symmetry, the structures exhibit the polarization rotation up to 90° and peaks of full circular dichroism and operate as circular polarizers within certain ranges of wavelengths in the visible. We discuss the observations on the basis of general principles (symmetry, reciprocity, and reversibility) and conclude that the extreme optical chirality is determined by the chiral localized plasmonic resonances.
No takes yet. Share an insight, caveat, or question.
A 2014 study studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: