Figure 3From: Porous silicon Bloch surface and sub-surface wave structure for simultaneous detection of small and large moleculesSimulated and experimental reflectance spectra of optimized (a) step and (b) gradient index PSi BSW/BSSW sensor in air. The resonance at the lowest angle for each sensor corresponds to the BSW mode while the other resonances are BSSW modes. Simulations show good agreement with experiment, with small error derived from nonlinear refractive index changes within the PSi multilayer.Back to article page