基于平行波导横向耦合理论,研究了矩形气孔阵列的双芯光子晶体光纤的耦合特性,并数值计算了光纤的结构参量对耦合特性的影响。计算结果表明,在1.55μm波长处,增大竖直方向气孔间距或缩小横向气孔间距并减小气孔半径都有利于减小光纤的耦合长度,耦合长度差也相应减小。在此基础上设计了一种基于矩形晶格结构具有耦合长度极短(125μm)、分离比较高(38dB)的偏振分束器。 Based on the theory of transverse waveguide parallel coupling, the coupling characteristics of double-core photonic crystal fiber with rectangular aperture array are studied, and the influence of the structural parameters of the fiber on the coupling characteristics is numerically calculated. The calculated results show that increasing the vertical stomatal spacing or decreasing the lateral stomatal spacing and decreasing the stomatal radius at the wavelength of 1.55μm can reduce the coupling length and decrease the coupling length difference. Based on this, a polarization beam splitter based on a rectangular lattice structure with very short coupling length (125μm) and high separation (38dB) has been designed.