Fig. 3. Calculated electromagnetic field distribution of the porous nano-silver film at a Raman excitation wavelength of 532 nm using the FDTD method. Shown are the 90 nm-thick nanoporous Ag films transferred from AAO templates with diameters of (a) 50, (b) 70, and (c) 90 nm to the PMMA substrates. Also shown are the 90 nm-thick nanoporous Ag films transferred from the AAO templates with diameters of (d) 50, (e) 70, and (f) 90 nm to the PDMS substrates.
