Figure 4. Fabricated photonic nanostructures with different number of lamellae for multivariable vapour sensing.

(a–d) Schematics and SEMs of nanostructures with 2, 3, 4 and 6 lamellae, respectively. (e) Nanostructure with six lamellae and microribs. (f) Histogram of automated image analysis of lamellae thickness in six-lamellae nanostructures. Thickness measurements of lamella were taken 400 nm from the centre of the ridge. Resulting thickness of 86±6 nm (mean±1 σ, n=70) was a convolution of real thickness and image analysis uncertainty of±2 nm of edge determination.