研究了具有二重旋转对称性的椭圆介质柱光子晶体的宽带全角准直色散特性及其在分束器方面的应用。利用平面波展开法计算其色散关系,发现该类结构的TE偏振模式在较宽的带宽内存在跨越整个第一布里渊区的平直等频线,利用这些平直等频线实现了宽带全角超准直光传输。在此基础上设计了一种Y型能量分束器,时域有限差分(FDTD)仿真结果表明,该分束器对内置二维点光源和高斯光源均具有很好的分束性能。以上研究在光子器件集成、定向耦合等领域具有潜在的应用价值。 The broadband full-angle collimation dispersion of elliptical dielectric column photonic crystals with double rotational symmetry and its application in beamsplitter are studied. Using the plane wave expansion method to calculate the dispersion relation, it is found that the TE polarization mode of this kind of structure exists the flat equipotential lines across the entire first Brillouin zone over a wide bandwidth, and the wide-angle full-width Ultra-collimated light transmission. Based on this, a Y-shaped energy beamsplitter was designed. The finite-difference time-domain (FDTD) simulation results show that the beamsplitter has good beam splitting performance for the built-in two-dimensional point light source and Gaussian light source. The above research has potential application in the field of photonic device integration and directional coupling.