A new structure of photonic bandgaps: metamorphosis

Photonic crystals with two different length scales are known to have a simple scaling property under the interpolation parametrized by a length scale s that the frequencies of eigenmodes scale by the inverse of s. We found that photonic crystals can have a nontrivial transformation property of metamorphosis under a certain interpolation. During the metamorphosis, the first bandgap that is present at the beginning gradually shortens and disappears, while the second bandgap which is initially absent begins to appear and eventually becomes a new first bandgap.