Figure 4: (a) The band structure of PMMA photonic crystal arranged in a square lattice for the TM polarization. The radii of the cylinders are . The relative permittivity of the PMMA is 2.6. Near the point, there is also a Dirac-like cone dispersion. The inset is the enlarge part near the Dirac-like point shown by blue solid region. (b) The field distributions for a Gaussian beam illumination. The Gaussion beam parameters are the same as in Figure 2.