Reflective behaviour of T_sp (green, left), T_sac (red, centre) and T_honey (blue, right). Presented are R (top, solid lines) and H_R (top, dashed lines) and AID (bottom). AID measurements show normalized intensity (normalized to maximum value) as a function of detector angle (θ_det) in reference to the incident light, with the sample positioned at a 10 degree angle, for different wavelengths (λ). For T_sp, R and H_R are shown as a function of etching time and AID measurements are shown for samples etched at 6.5 mins (left) and 11 mins (right). For T_sac, R and H_R are shown as a function of d_asi. R and H_R of a flat, polished wafer is included as reference. AID measurements are shown for the sample with d_asi = 1500 nm. For T_honey, R and H_R are shown as a function of etching time (step 4) for honeycombs with p = 2 μm (R = dashed/dotted, H_R = dotted) and p = 3 μm (R = solid, H_R = dashed). AID measurements are shown for samples with p = 3 μm etched for 12 mins, with right image showing AID normalized to max value in θ_det = 30^∘–90^∘ range.