Chiral conformations and experimental optical responses. (a) Schematic diagram of four chiral geometries in one metamolecule with achiral (a, planar conformation), levorotatory (L), dextrorotatory (D), and racemic (r) conformations. (b) Experimental copolarized transmission amplitude of the metamaterial at the four conformations with RCP and LCP light at normal incidence. The RCP and LCP spectra reveal identical responses for a- and r-conformations, and spectral difference emerges at mode II at L- and D-conformations. (c,d) Circular dichroism and optical rotatory dispersion spectra at the four different chiral conformations.