Optical Bistability with Symmetry Breaking and Its Related Phenomena

对称性破缺的光学双稳态及其相关现象

基本信息

批准号：
59460033
负责人：
YABUZAKI Tsutomu
金额：
$ 4.86万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1984
资助国家：
日本
起止时间：
1984 至 1986
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-59460033/
关键词：
Optical Bistability 非線型現象

项目摘要

This project was on a new type of optically bistable system which exhibits symmetry-breaking bifurcations. We proposed this system and studied theoretically and experimentally on its static and dynamical behavior. The bistability is based on the optically induced Faraday effect due to the spin polarization in alkali atoms. It can be achieved by a single feedback of the light beam without the use of an optical cavity unlike other systems. The states of the system can be characterized by the orientation of atomic spin polarization or by the helicity of the light in the cell. The symmetry-breaking bifurcation was clearly demonstrated experimentally.We also predicted that continuous spin precession can be possible when we apply a transverse magnetic field to the system. The spin precession is sustained by the optical feedback despite the thermal relaxation. Recently, the precession was confirmed experimentally. The precession frequency was proportional to the magnetic field amplitude as ex … More pected by the theory. The upper limit of the frequency (-10MHz) turned out to be limited by the presence of magnetic inhomogeneity. Without this, more rapid oscillation can be possible.We also studied on chaotic behavior which can be seen in this system. With use of numerical calcurations, we found many interesting strange attractors and bifurcations. Among them "symmetry recovering crises" and "hidden chaos", which we named, was found to be universal phenomena seen in various physical systems.As an extension of our system, we analysed a two-beam system, where the two parts are coupled through the atomic diffusion. In the no-coupling case, it is easy to see that the system shows quadrastability. We found that, even in other cases, it can possess four stable states, if we use laser beams intense enough. We can further extend the analysis to N-beam and two-dimensional systems, which will play an impatient role in optical computers in future.We note that stimulated by our proposal to utilize spin polarization for optical bistability, several groups in the world have been worked out and obtained many fruitful results. Less

该项目是在一种新型的光学双态系统上，该系统表现出对称性分叉。我们提出了这个系统，并在理论上介绍了其静态和动态行为。双态性基于碱原子中的自旋极化引起的光学诱导的法拉第效应。它可以通过光束的单个反馈来实现，而无需使用光腔，与其他系统不同。系统的状态可以以原子自旋极化的方向或细胞中的光的螺旋性为特征。实验清楚地证明了对称性分叉。我们还预测，当我们将横向磁场应用于系统时，可以进行连续的旋转预防。旋转预防由光反馈目的地维持热松弛。最近，预防已通过实验确认。预防频率与磁场放大器成正比，因为该理论更倾向于。频率（-10MHz）的上限受到磁不均匀性的限制。没有此事，就可以实现更快的振荡。我们还研究了该系统中可以看到的混沌行为。通过使用数值计算，我们发现了许多有趣的奇怪攻击者和分叉。其中，我们命名的“对称恢复危机”和“隐藏的混乱”是在各种物理系统中看到的普遍现象。作为系统的扩展，我们分析了一个两光束系统，其中两个部分通过原子扩散耦合。在无耦合情况下，很容易看到系统显示出典当的性能。我们发现，即使在其他情况下，如果我们使用足够强烈的激光束，它也可能潜在四个稳定状态。我们可以将分析进一步扩展到N梁和二维系统，这将在未来的光学计算机中发挥不耐烦。较少的