Pesch M, Grosse Westhoff E, Ackemann T, Lange W
Institut für Angewandte Physik, Westfälische Wilhelms-Universität Münster, Corrensstrasse 2/4, D-48149 Münster, Federal Republic of Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Jul;68(1 Pt 2):016209. doi: 10.1103/PhysRevE.68.016209. Epub 2003 Jul 14.
We determine the limits of stability of the homogeneous state of a pattern forming optical system in dependency on the wave number by experimental means. The measurement becomes feasible by adopting a scheme based on a Fourier filtering technique. The system under study is a single-mirror feedback arrangement using sodium vapor as the nonlinear medium. The experiment confirms the existence of multiple instability regions of the homogeneous state expected by theory. The measurements do not agree quantitatively with the marginal stability curve determined by a linear stability analysis of an infinitely extended homogeneous system. We study the system numerically and demonstrate that the results of the simulations for the case of a Gaussian beam can be reproduced by a simple modification of the linear stability analysis which accounts for the finite diameter of the input beam. This explains the wave number dependent systematic deviations between the experiment and the linear stability analysis of the infinitely extended system.
我们通过实验手段确定了一个形成图案的光学系统均匀态稳定性的极限，该极限取决于波数。采用基于傅里叶滤波技术的方案使测量变得可行。所研究的系统是一种使用钠蒸气作为非线性介质的单镜反馈装置。实验证实了理论预期的均匀态存在多个不稳定区域。测量结果在数量上与通过对无限扩展均匀系统进行线性稳定性分析确定的边际稳定性曲线不一致。我们对该系统进行了数值研究，并证明对于高斯光束情况的模拟结果可以通过对线性稳定性分析进行简单修改来重现，该修改考虑了输入光束的有限直径。这解释了实验与无限扩展系统的线性稳定性分析之间与波数相关的系统偏差。
