Huneus F, Lange W, Ackemann T
Institut für Angewandte Physik, Westfälische Wilhelms-Universität Münster, Corrensstr. 2/4, D-48149 Münster, Federal Republic of Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2006 Jan;73(1 Pt 2):016215. doi: 10.1103/PhysRevE.73.016215. Epub 2006 Jan 18.
In this paper we analyze experimentally and theoretically the competition between two pattern forming instabilities in a single mirror feedback scheme with sodium vapor as the nonlinear medium. Two types of structures with different transverse wave numbers are observed experimentally, if the spatial phase modulation of the light field is varied. This phenomenon results from the combination of a nonlinear self-lensing effect on the one hand and of the externally controlled phase front curvature of the light field on the other. A linear stability analysis yields two instabilities whose length scales match quite well the experimental findings. Further analysis reveals the mechanism of length-scale selection in this system and demonstrates the possibly crucial role of phase front curvature in optical pattern formation.
在本文中，我们通过实验和理论分析了以钠蒸汽为非线性介质的单镜反馈方案中两种图案形成不稳定性之间的竞争。如果改变光场的空间相位调制，实验中会观察到两种具有不同横向波数的结构类型。这种现象一方面源于非线性自聚焦效应，另一方面源于光场的外部控制相位前沿曲率。线性稳定性分析得出两种不稳定性，其长度尺度与实验结果相当吻合。进一步分析揭示了该系统中长度尺度选择的机制，并证明了相位前沿曲率在光学图案形成中可能起的关键作用。
