Xie Ping, Zhang Zhao-Qing
Department of Physics and Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2004 Mar;69(3 Pt 2):036601. doi: 10.1103/PhysRevE.69.036601. Epub 2004 Mar 8.
We study in detail the excitation of gap solitons in finite-sized two-dimensional photonic crystals under various kinds of source configuration, including two external beams along different incident directions and a point source at different locations inside the sample. We find different types of gap solitons, such as soliton trains along different symmetry axes of the photonic crystal and soliton sets with a higher rotational symmetry. In the case of a single external beam, we find the existence of an optimal beamwidth d(opt) for the excitation of gap solitons, and the value of d(opt) is close to the diameter of single localized envelopes of the excitation. In the case of a point source, it is found that the excitation threshold depends only on the distance between the source and the nearest cylinder, and its value increases nearly exponentially with distance.
我们详细研究了在各种源配置下有限尺寸二维光子晶体中带隙孤子的激发情况，包括沿不同入射方向的两束外部光束以及样品内部不同位置的点源。我们发现了不同类型的带隙孤子，例如沿光子晶体不同对称轴的孤子列以及具有更高旋转对称性的孤子集。在单个外部光束的情况下，我们发现存在一个用于激发带隙孤子的最佳光束宽度d(opt)，并且d(opt)的值接近激发的单个局域包络的直径。在点源的情况下，发现激发阈值仅取决于源与最接近圆柱体之间的距离，并且其值随距离几乎呈指数增加。
