Transmission properties near Dirac-like point in two-dimensional dielectric photonic crystals
1 MOE Key Laboratory of Advanced Micro- Structured Materials, School of Physics Science and Engineering, Tongji University - Shanghai 200092, China
2 Institute of Solid State Physics, Shanxi Datong University - Datong 037009, China
Received: 19 July 2014
Accepted: 16 September 2014
We study the wave transport properties near the Dirac-like point at the Brillouin zone center in two-dimensional dielectric photonic crystals with finite thickness. Both simulations and microwave experiments confirm that the transmittance is nearly inversely proportional to the length (L) of the samples in the propagation direction near the Dirac-like point. This transmittance law comes from the conically shaped dispersion. Since the conical singularity at the Brillouin zone center corresponds to zero refractive index, the field at the Dirac-like point contains a basic component of nearly uniform field. In contrast, the field at the Dirac point in the corner of the hexagonal Brillouin zone contains a basic component of inhomogeneous standing-wave–like field.
PACS: 42.70.Qs – Photonic bandgap materials / 42.25.Bs – Wave propagation, transmission and absorption / 11.55.Fv – Dispersion relations
© EPLA, 2014