Fig. 2: Circular polarization-resolved optical characterization of S-NPB.
From: Large exchange-driven intrinsic circular dichroism of a chiral 2D hybrid perovskite

a Ratios of the voltages of the \(1f\) and the DC components (\({V}_{1f}/{V}_{{{{{{\rm{DC}}}}}}}\)) as a function of wavelength measured with a lock-in amplifier; data are plotted for both S-NPB and R-NPB, and for both before and after the coating of Al2O3. b Schematic illustration of the LCP light and RCP light reflected off of an S-NPB single crystal (\({R}_{{{{{{\rm{L}}}}}}}\): reflectivity for LCP light; \({R}_{{{{{{\rm{R}}}}}}}\): reflectivity for RCP light). c CP-differentiated \(n\) and \(k\) for S-NPB. d Differences in \(n\) and \(k\) between LCP and RCP for S-NPB. e CP-differentiated \({\varepsilon }^{{\prime} }\) and \({\varepsilon }^{\prime\prime}\) for S-NPB. f Solid lines: differences in \({\varepsilon }^{{\prime} }\) and \({\varepsilon }^{\prime\prime}\) between LCP and RCP for S-NPB. Blue-dashed line: the change in \({\varepsilon }^{{\prime} }\) caused by the change in \({\varepsilon }^{\prime\prime}\) calculated using the Kramers-Kronig (K-K) relations. RCP: right-hand circularly polarized light. LCP: left-hand circularly polarized light.