  We show how spatial dispersion can be used as a mechanism to customize the
longitudinal profiles of electric fields inside modulated wire media, using a
fast and remarkably accurate 1D inhomogeneous model. This customization gives
fine control of the sub-wavelength behaviour of the field, as has been achieved
recently for transverse fields in simpler slotted-slab media. Our scheme avoids
any necessity to run a long series of computationally intensive 3D simulations
of specific structures, in order to iteratively converge (or brute-force
search) to an empirical `best-performance' design according to an abstract
figure-of-merit. Instead, if supplied with an `ideal waveform' profile, we
could now calculate how to construct it directly. Notably, and unlike most work
on photonic crystal structures, our focus is specifically on the field profiles
because of their potential utility, rather than other issues such as band-gap
control, and/or transmission and reflection coefficients.
