Jović D, Arsenović D, Strinić A, Belić M, Petrović M
Opt Express. 2005 Jun 13;13(12):4379-89. doi: 10.1364/opex.13.004379.
We present a comprehensive numerical study of (2+1)D counterpropagating incoherent vortices in photorefractive crystals, in both space and time. We consider a local isotropic dynamical model with Kerr-type saturable nonlinearity, and identify the corresponding conserved quantities. We show, both analytically and numerically, that stable beam structures conserve angular momentum, as long as their stability is preserved. As soon as the beams loose stability, owing to radiation or non-elastic collisions, their angular momentum becomes non-conserved. We discover novel types of rotating beam structures that have no counterparts in the copropagating geometry. We consider the counterpropagation of more complex beam arrangements, such as regular arrays of vortices. We follow the transition from a few beam propagation behavior to the transverse pattern formation dynamics.
我们对光折变晶体中（2 + 1）维反向传播的非相干涡旋进行了全面的时空数值研究。我们考虑了具有克尔型饱和非线性的局部各向同性动力学模型，并确定了相应的守恒量。我们通过解析和数值方法表明，只要稳定光束结构的稳定性得以保持，它们就会守恒角动量。一旦光束由于辐射或非弹性碰撞而失去稳定性，其角动量就不再守恒。我们发现了新型的旋转光束结构，这些结构在同向传播几何结构中不存在对应物。我们考虑了更复杂光束排列（如规则涡旋阵列）的反向传播。我们跟踪从少数光束传播行为到横向图案形成动力学的转变。
