Fig. 4: Comparison of CD between single crystals and thin films.

a Optical transmittance (averaged between LCP and RCP) for an S-NPB single-crystalline slab as a function of slab thickness and wavelength, calculated using the refractive index data in Fig. 1d. The data is plotted in log₁₀ scale (the numbers in parentheses of the color bar show the transmittance values in a linear scale). b Map of the ellipticity \(\theta\) (in degrees) as a function of wavelength and thickness of the single-crystalline S-NPB slab, calculated using the refractive index data in Fig. 2c. c Ellipticity angle \(\theta\) measured for light reflected off of the S/R-NPB single crystals (calculated using data shown in Fig. 2a). d Ellipticity angle \(\theta\) for light reflected off of the S-NPB single crystal at various temperatures from 290 K to 50 K. e Ratios of the \(1f\) voltage (\({V}_{1f}\)) and DC voltage (\({V}_{{{{{{\rm{DC}}}}}}}\)) of the lock-in measured in reflectance for a 320-nm thick, annealed crystalline S-NPB film. The data were taken at randomly selected spots on the sample. f Plots of average and standard deviation of ellipticity angle \(\theta\) in reflectance, calculated using the data shown in e. The shaded area in f represents the standard deviation of the data shown in e.