title: Precise identification of Dirac-like point through a finite photonic crystal square matrix.
abstract: The phenomena of the minimum transmittance spectrum or the maximum reflection spectrum located around the Dirac frequency have been observed to demonstrate the 1/L scaling law near the Dirac-like point through the finite ribbon structure. However, so far there is no effective way to identify the Dirac-like point accurately. In this work we provide an effective measurement method to identify the Dirac-like point accurately through a finite photonic crystal square matrix. Based on the Dirac-like dispersion achieved by the accidental degeneracy at the centre of the Brillouin zone of dielectric photonic crystal, both the simulated and experimental results demonstrate that the transmittance spectra through a finite photonic crystal square matrix not only provide the clear evidence for the existence of Dirac-like point but also can be used to identify the precise location of Dirac-like point by the characteristics of sharp cusps embedded in the extremum spectra surrounding the conical singularity.
authors.affiliation: College of Materials Science and Opto-Electronic Techology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
authors.forename: Guoyan
authors.initials: G
authors.lastname: Dong
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Optics, Shandong University, Jinan, 250100, China.
authors.forename: Xiulun
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Optics, Shandong University, Jinan, 250100, China.
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Meng