Jović Dragana, Denz Cornelia, Belić Milivoj
Institut für Angewandte Physik and Center for Nonlinear Science (CeNoS), Westfälische Wilhelms-Universitt Münster, Münster, Germany.
Opt Express. 2011 Dec 19;19(27):26232-8. doi: 10.1364/OE.19.026232.
Using numerical analysis we demonstrate the existence of vortex solitons at the edge and in the corners of two-dimensional triangular photonic lattice. We develop a concise picture of their behavior in both single-propagating and counterpropagating beam geometries. In the single-beam geometry, we observe stable surface vortex solitons for long propagation distances only in the form of discrete six-lobe solutions at the edge of the photonic lattice. Other observed solutions, in the form of ring vortex and discrete solitons with two or three lobes, oscillate during propagation in a way indicating the exchange of power between neighboring lobes. For higher beam powers we observe dynamical instabilities of surface vortex solitons and study orbital angular momentum transfer of such vortex states. In the two-beam counterpropagating geometry, all kinds of vortex solutions are stable for propagation distances of the order of typical experimental crystal lengths.
通过数值分析，我们证明了二维三角形光子晶格边缘和角落处存在涡旋孤子。我们建立了它们在单束传播和反向传播光束几何结构中行为的简洁图像。在单束几何结构中，我们仅在光子晶格边缘观察到离散的六瓣解形式的表面涡旋孤子在长传播距离内是稳定的。其他观察到的解，如环形涡旋和具有两瓣或三瓣的离散孤子，在传播过程中振荡，这表明相邻瓣之间存在功率交换。对于更高的光束功率，我们观察到表面涡旋孤子的动力学不稳定性，并研究了此类涡旋态的轨道角动量转移。在双束反向传播几何结构中，对于典型实验晶体长度量级的传播距离，各种涡旋解都是稳定的。
