利用平面波展开法研究了液体介质金刚石(diamond)晶格结构三维光子晶体的带隙和带宽。选择金刚石结构材料TiO_2作为基底,在金刚石晶格光子晶体的球形空洞内填入待测质量摩尔浓度不同的溶液材料,得到了溶液填充的三维光子晶体在不同偏振模式下的禁带宽度。模拟显示:溶液的浓度变化与光子晶体带隙宽度或输出功率变化接近线性关系,而线性相关程度受填充空气孔内液体质量摩尔浓度的影响,进行了多组参数比对与优化,最终获得了线性度最高的禁带宽度或输出功率与溶液质量摩尔浓度的对应关系。 The bandgap and bandwidth of liquid crystal lattice 3D diamond photonic crystal are studied by plane wave expansion method. The diamond material TiO 2 was selected as the substrate, and the solution cavity material was filled into the spherical cavity of the diamond lattice photonic crystal to obtain the forbidden band width of the solution-filled three-dimensional photonic crystal in different polarization modes. The simulation results show that the concentration of the solution changes linearly with the change of band gap or output power of the photonic crystal, and the linear correlation is affected by the molar concentration of liquid in the filled air pores. The relationship between the maximum linearity of the forbidden band width or the output power and the molar mass of the solution.