Band gaps structure and semi-Dirac point of two-dimensional function photonic crystals
Zhang Si-Qi1, Lu Jing-Bin1, Liang Yu2, Ma Ji2, Li Hong3, Li Xue1, Liu Xiao-Jing2, Wu Xiang-Yao2, †, Meng Xiang-Dong2
       

The band gaps structure of two-dimensional function photonic crystals for the triangle lattice, , , function coefficient , medium column radius . (a) TE wave, (b) TM wave, there is one semi-Dirac point A for the TM wave. In the vicinity of the A point, the dispersion relation is linear along the XM direction and quadratic along the direction.