Measured reflectivity spectra for φ = 0°. Insets are the distribution of the E field at the interface. The corresponding incident wavelengths and incident angles are indicated respectively. (a) For Sample A with TM-polarized incident light. (b) For Sample A with TE-polarized incident light. (c) For Sample B with TM-polarized incident light. (d) For Sample B with TE-polarized incident light.