Diffraction manipulated resonators with intracavity photonic crystals

Photonic crystals (PCs), the materials with periodic in space refraction index, is an object of intensive study since their proposal in 1987. The studies were focused initially on the temporal dispersion characteristics of the PCs. The dispersion curves were found to modify substantially due to the periodic modulation of the index, and to display a band structure. More recently it was found that the spatial dispersion (diffraction) characteristics also modify substantially in periodic materials: the diffraction can become negative, or can vanish to zero [1, 2], resulting in the so-called self-collimation effect in the latter case.