  A 3D woodpile structure tunable plasma photonic crystal is designed,
simulated, and experimentally characterized over the S - X band of the
electromagnetic spectrum. The measurements confirm that the electromagnetic
response is rich in dynamics. The photonic crystal's reconfigurability,
achieved through individual discharge control of the properties of the woodpile
plasma columns, offers an unprecedented opportunity to better resolve the
interactions between both the Bragg and localized surface plasmon modes which
dominate the spectrum at lower frequencies. Both the experiments and
simulations reveal evidence for the coupling of Bragg and surface plasmon modes
through a Fano resonance.
