运用平面波展开法，模拟计算了四种散射体横截面形状分别为圆柱形、沙漏形、元宝形和鸭式的二维光子晶体结构的带隙，并且四种散射体形状的对称性依次降低。结果表明，散射体形状为鸭式的二维光子晶体相比散射体为圆柱形、沙漏形、元宝形的光子晶体更容易产生较宽的完全带隙。并且还进一步研究了介电常数和散射体的大小半圆半径对鸭式二维光子晶体的完全带隙的影响，结果表明，当介电常数为26.6，大半圆半径为0.331 μm，小半圆半径为大半圆半径的0.535 倍时，完全带隙达到了最大值，该最大值为0.058 (wa/2πc)。

Complete band gap of two-dimensional photonic crystal structure with four different scatterers (circle, hourglass, wing, duck) are simulated. The symmetry of the four scatterers in turn reduce. The results show that the duck-shaped scatterers of photonic crystals are more likely to produce complete band gap than other shapes of scatterers. The influence of dielectric constant and the geometric parameter of duck-shaped scatterer on the complete band gap is studied. The results show that when the dielectric constant is 26.6, the big semicircular radius is 0.331 μm , and the radius of small semicircular is 0.535 times that of the big semicircular, the value of complete band gap reaches the maximum value of 0.0583 (wa/2πc).