(a) Schematic picture of a pseudospin-1 superlattice formed by a Kronig-Penney type photonic potential. (b) The wedge-shaped dispersion structure of pseudospin-1 EM waves near for a superlattice realized by alternating stacks of PC1 and PC2 (see Figure 2). Both PC1 and PC2 have the same thickness , i.e., the spatial period of the superlattice is . The photonic potential is set at . (c) The magnitude of electric field distribution of a Gaussian wave packet at with the reduced center frequency and the half width . (d) and (e) The magnitude of electric field distributions of the Gaussian wave packet at in a single PC (left panel) and in the PC superlattice (right panel) with the initial propagation direction in an angle (d) and (e), respectively. The results show the supercollimation induced by the superlattice. Adapted from .